Avoiding FUSEBOX "China Syndrome" MELTDOWN: Pre-emptive fix

Checking, testing and cleaning chassis grounds has been established industry procedure since the introduction of large scale electronics in the late 60's and early 70's. Anyone not doing it has no business performing electrical diagnosis.

Chassis grounds are a good idea (The car is the biggest and best wire in the system) and has continuously proven so since the 2 wire idea was abandoned in the 30's. Wires and their connections are the biggest source of trouble and that method doubles it. I won't even go into the issues of weight, expense and complexity.

 

The only problems run into regarding the fuse's themselves is with the old ceramic Bosch type. The contact area is quite small and the fuse boxes are never mounted in an area where very strong contact tangs are user friendly. In this type of situation aero type circuit breakers would work fine but additional space would be needed for housing them. I use the Aero push to reset breakers on every race car I build but the cost will become a factor when looking at an inexpensive fix for this problem.

The ATO fuses have proven problem free as the blade contacts have enough surface area to reliably handle more current than the fusible link portion. My main focus to date has been with the ATO type fuse boxes as this is where we see most of the problems. As there are slight variations from model to model (Mondial T Cab to Mondial T Coupe...) I have had my hands full drawing up diagrams for each model and then building templates and prototypes for each. Daunting task when they are all being dealt with at the same time and trying to find a cost effective method that they can all share. Too small of a production run on each model to sublet produce yet quite a task to hand build one at a time. While waiting for the custom parts I decided to build 20 of each and see how efficient they can be made.

Edwardo's solution is well founded but still leaves a few issues not addressed from what my research has shown. It took looking long and hard at a great many failures over the years to see all of the weak points and to then identify an acceptable fix that could be implemented on each model. Some of the failures were only seen once and could, in a round about way, be explained due to other "creative wiring" throughout the car. Some of the single type failures could on the other hand could be predicted when looking at what is going on. Why it happened on only one subject I never bothered to dig deep enough to identify as that would take countless hours and destruction testing which most owners would frown upon. I am hired to fix them not cut them apart, I do that on my own time with failed parts.

There are many ways to deal with these problems and no one way is correct. I choose to take the low tech, easy to diagnose in the future, easy to install method. I have looked at doing a higher tech solution using replaceable transistors and printed circuits but decided using an over designed low tech solution was the better route as it mimicked the technology used on the OE system while dealing with the problems and still making future diagnosis a bit more owner friendly. Simple enough to do as a preventative measure yet over engineered enough to deal with a system that has seen better days. As the trend continues and these systems age further we will all be seeing an exponential increase in failures as I have over the last year or so. It is for this reason I choose to find a simple solution to deal with it now.

Dave

 

Dave, how many variations have you seen on any one models fuse box? I've noticed that although there is only two wiring diagrams for the mondial (8) & (3.2,t) there are in fact 3 different boxes from what I've seen. I do wonder how Clive is going to handle that, no word yet from him -radio silence-

i have an '81 mondial 8 but the box is not as shown in the diagrams for that yr or for the yrs after, there seems to be a difference in the lower "X" connection and what is being fed from there, no diagrams I have show what it is.'

So in reference to what you're saying I agree completely there are many variables that make a project for complete replacement very expensive.

 

Quote :Chassis grounds are a good idea (The car is the biggest and best wire in the system) and has continuously proven so since the 2 wire idea was abandoned in the 30's. Wires and their connections are the biggest source of trouble and that method doubles it. I won't even go into the issues of weight, expense and complexity.

As result of my electrical problems I solved them with the second wire idea. See discription on my thread :

http://www.ferrarichat.com/forum/showthread.php?t=209843 -- 3 chapter.

Weight : 20 m of 4 mm2 wire and about 20 contacts....200 gram ;
Expense : 20 euro ;
Complexity : a work of 4 hours by 1 man.

All contacts are easy to reach, the wires can easely hidden...you just have to connect the black wires one after oneother.
The chassis stay in contact with them also, but the current passes much easyer in the copper wires.

Enzo52

 

Photo your box and I will try to identify what it came from.

Did one of the kit installs in a Mondial QV that had a late 3.2 Cab box installed about 4 yrs back and was already well on its way to going bad for the second time. Trouble came in when the past owner kept the original cover for show reasons.......

I have diagrams for 7 models:
Mondial 8
Mondial QV 84/85 Bosch ceramic fuse
Mondial 3.2 Early ATO type fuse
Mondial 86/87
Mondial 88
Mondial T Coupe
Mondial T Cab

I have ordered fuse boxes for F-40's and recieved a TR part# box inside the F-40 part# box with who knows what fuse box inside that. Clive has a challange ahead of him! I have my part worked out as I standardized the parts required for me to build the kits down to variations of 2 manufactured parts.

Dave

 

here's the box, the white paper on the bottom is long since faded. it's from a 1981 mondial 8. the bottom right connection point labeled as "X" per WSM has three additional connections, hopefully this diagram works;
[- - - 0 0 0 0 - - - - ] the zero's indicating blank/not used. the first 3 on the right of the 4 are in question.
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With the early boxes such as this you are going to have to go by wire color and work backwards. Looks like an early Mondial QV box, circa 84, if I was going to guess without digging through the books. Mondial 8's didnt have the extra 2 relays in the lower right corner by memory. Are the wire colors light blue/ yellow and white just to the left of the open spaces?

Dave

 

I was afraid of this. Not sure, but I believe the Mondial T first year, 1989 had a different box. I can get a pic of that one and compare, but they didn't have the seat mice. OR perhaps that fuse arangement is held near the ECU area?

I kept my original box top, and used that, as the new one off the NOS replaced from Europe few years back didn't have the lettering in the cover.

SO: What could be the difference on the coupe vs cab?

ALSO, I'm wondering about the Valeo models

rik

 

the lower two relays according the manual shouldn't be there, but they are used in this particular application. the wire colors for that connector are..
LB/Y; LB/Y; WH; 0 0 0 0 WH/R; R/B; WH/B; BR/WH

with B being blue.

 

Then I believe you are talking about connection "Y" of a QV box from the 84'ish era. I am only going from memory and could be mistaken. I am up against the wall with deadlines to have cars preped for the Colorado Grand and our local Fall Tour and do not have the time to verify these statements for a day or two. One sure (? if one is to believe the wiring diagrams which are known to be full of mistakes) thing is it has already been replaced some time in the past and wasnt original to the car.

Dave

 

It is because of all these minor variances that reproduction of the fuse boxes is such a daunting task. Which one do you use as the base model and adapt all others to? Adaptor harness variances....

Using the original covers with updated boxes can lead to a great deal of confusion If it is taken for granted the cover and the box are a mated pair. There are changes in fuse placement and relay location albeit minor, dealt with that already. Assume nothing when it comes to these!

This also brings to light the base reason to retain the box in the car if it can be salvaged, which most can. One can now start to see how much time had to be devoted to identifying the areas of problems, compare one variant to another within the same model run.... I have flow charts for known failures and predicted future failures for each of the Mondial and series and have decided to break it down to 3 kits dedicated to the Mondials. Failures I have seen or predicted only on the 3.2's are addressed on all of the boxes up to the 88 Mondial Cab as they are quite close to one another. Same type of issues with the TR / F-40's as there you have the early box, mid run box and then the late 512 type design. Lets just say there are a LOT of notes generated before any hands on building started!

The temptation was to address each issue individually on each model but that would take a team of folks working on this making any fix extremely expensive. Fortunately they all share a great deal of the same circuitry and in turn problems and that has allowed me to ignore minor variations and focus on the similarities and problems.

I have all the TR series and ATO fused Mondials done to my satisfaction and then took the time to spec custom parts to be manufactured that will fit all of these applications. I started here only because those represent the bulk of the local cars needing immediate attention. These parts will also fit the early Mondial, and 328 series boxes and Steve's request to look into the window relay issues but I have yet to put a hard focus in that area. Before proper production is started I will look into these as the insight might show that some changes to my hand built kits could benefit enough individuals that incorporating this into the standard kit is justified. My goal is to widdle this down to 6 kits to address all of the issues following the KISS logic and in turn easily affordable. As with any engineering challenge of this nature, one can positively state there will be future problems down stream of the fuse box. The fuse box is at the top of the waterfall and is expected to distribute 12 to 14.5 volts to various circuits throughout the car and this is what I am doing. As it stands now many of the circuits supplied by ALL of these boxes are lucky to see 10.25 volts which causes an incredible amount of hard to explain "gremlins" that come and go. Ohm's Law says there have been a lot of TR fan motor transistors that have fallen prey to this problem!

Steve, John returns from a business trip first part of next week and I will see if he can bring the "mule" back in and we can use that to test the window thoughts. I will do the same with one of my 308's using resistors and see what we come up with.

Dave

 

Dave and Steve,

Thanks for the kind words. My fuseblock "business" came out of a need to repair my fusebox because it was causing new trouble every single time I drove the car. (The straw that broke the camel's back was when the car overheated because the fans didn't come on). It started with a set for me and an offer to build a few more sets for others on fchat because I figured some people didn't have the tools or skills to build their own. The original design is not even mine, and I don't want to take credit for it. Nuvolari did the original design and posted it here. My first set was simply a copy of his. I then improved it with 12 guage copper soldered bus bars on the back, rather than using wires with crimp connectors to piggyback the connections, which I saw as another place to introduce resistance and bad connections. When I got too many people who wanted them for me to justify the incredible amount of time it took to build each set completely by hand, I farmed out a production run of the aluminum back plates to another fchatter (Chris Marsh) who has a machine shop. He stamps the back plates and anodizes them. They are perfectly identically machine-made so they look and fit perfectly. So I kinda of fell into the fuseblock business. Unfortunately, I still have to hand rivet and solder each set, so it's still time-consuming. But I take pride in the fact that I am making 308s more reliable and providing a service that a lot of people appreciate. I actually enjoy taking a little time to sit downstairs in my shop and solder with some music going and a big cup of coffee...except when I have been traveling and the orders pile up and I get backlogged. People don't tend to order them until their car is acting up and then they need them fast, so I hate to take too long to ship them. Anyway, I'm not trying to post a big ad here, I just wanted to give credit where it is due to Nuvolari for the original design and Chris for his awesome fabrication.

As for the windows, there are two issues as I see it. One is the old, hardened grease in the "gearbox" units that couple the electric motor to the pulley/cable system. Pulling that apart, cleaning out the glue-like grease and putting in new grease really does work wonders, but it's not the whole solution, and it's a giant pain in the butt. Disassembling those things totally blows and getting them back together right is a trick that requires practice, preferably on someone else's car. Most people like an easier solution.

To accomplish both up and down action on the windows, they reverse the polarity on the motor. So that means that the car can't use a chassis ground on the motor circuit in the door. They run two wires to the motor from the switch, and the wires reverse polarity depending on whether you are going up or down with the window. As a result, the path for the current to the window is: battery to fusebox to relay (which is activated by the ignition key) to window switch to motor, back to the switch and then to ground. It's a long path filled with connectors that can oxidize. The last time I had a door apart (it was the Mondial) I measured the voltage at the motor and it was something like 8 volts when the window was being raised....meaning there was a 4 volt loss across all the various connectors between the battery and the motor!! That's 1/3 the voltage! No wonder the damn thing is slow!! When I put a straight 12 V on the motor...the sucker went right up!

The window accelerators that various people sell (I can't remember who, sorry!) work by adding a relay in the door itself to switch the ground back and forth locally to the chassis, so that the path of the current doesn't have to go all the way back to the switch through a wire, then to ground. They definitely help. I built one as a test and it increased the voltage at the motor to 10 volts. Still not 12, but a 16% increase in voltage. The improvement to the window speed was considerable, though the window was still not fast! (I do not build these...I don't want to step on another fchatters toes. I only built one for fun as a proof of concept.)

Some people find that the replacement 308 fuseblocks help their window speeds a tad because the fuseblock on some of the cars is so corroded that they lose a lot of window voltage there. However, others don't experience as much of a benefit, because the resistance is elsewhere (particularly, in my opinion, the switch--clean them with contact cleaner, it helps!) Hence, I don't promote this as an advantage of the fuseblocks. It will probably help your windows a little--sometimes a lot--but it varies from car to car. It will also help headlights--again, varies from car to car.

Birdman

 

I agree with all you said except for this part. But maybe the early cars like mine are wired a bit different? In both my 77's, the ground terminal on the window switch connects directly inside the door to a ground terminal stud. The ground path is then directly to chassis ground, but via the rusty greasy door hinge pins.

I also do not believe the hard grease in the motors is that much of a problem. Once I cleaned the switch contacts, lubricated the cable pulleys, took out the extra jumper wires from the motors to the switch, cleaned all the connections and adjusted the glass, I can run the window up or down in about 4 seconds. If the engine is running its even faster (more volts). And this is with the ground going through the nasty door hinges. I intend to run a ground wire through the boot and bond it to the chassis directly at some point, but 4 seconds is pretty fast, all things considered, heavy grease and all, and I doubt the window speed can be much further improved.

And your fuseblocks cannot be over emphasized. Folks, if you have a 308 with a stock fuse panel, if it hasnt started failing yet, it will. The fuse block Birdman sells is simple, but well made and can better handle the current loads of the car than the original was ever capable of. Simply swapping out the fuse panel has repeatedly given peoples cars new life by waking everything up. Windows run faster, wipers, fans, blinkers, brighter headlights. The original panel breaks down and causes voltage drops system wide. Get the new panel, it will be one of the cheapest and best upgrades you can do to one of these old cars.

I have a sack full of aircraft circuit breakers ive collected over the years, and it would be cool to make a breaker panel for the 308. But I doubt the car would operate any better than it does now with the new fuseblocks. You cant easily improve a zero resistance connection

 

Then I will expand my compliments to all involved. It is a major undertaking and is done extreemly well. As with your fuse box project I am just skipping a few steps. If I see this many cars having problems here I am going straight into production in an attempt to lower the costs right away and have as few stages of prototype as possible. On the rest of your reply, I completely agree with every point made.

 

I LIKE this approach. Some may think a bit overkill, but you'll never have to worry again. I'm all for, on the older models, when used in a daily mode, upgrading the tech.

When I't concourse time, swap out for that judgement IF necessary.

Otherwise, daily driving, for all it's Barney Google fun, is NOT fun on the far and out traveling I do. IF I wanted my model T back, I'd of kept it.....

rik

 

All of this development is terrific and my hat is off to you guys..

Due to pressing electrical failures I purchased "the first of two" prototype uprated Mondial boxes from GT Auto Parts with the improved board - three months so far and doing ok. As said before, you notice little differences as things just seem to work better.

You guys are the best!

 

Unless they make guys pull off the fuse panel cover on a 308, whatever "panel" you put in to keep the car alive will be completely out of sight.

 

Paul, on the early 308 that is correct for the driver's side window switch which is mounted in the door.

On a later 308 or Mondial, the switches are in the center console of the car, between the seats. Long path. But if you want to talk about a really long path, check out the other window switch in your door which goes to the passenger window!! The wiring goes all the way across the car--twice!!

Jonathan

 

Thanks man! Check's in the mail.

Jonathan

 

John,

All the event cars are done and gone and I have time before the next round comes in. I want to follow through on Steves thoughts prior to going into production. I found a local manufacturer who is interested in building the parts for me on a limited scale. Exactly what I was looking for, a local small speciality company so I can keep my arms around it. I should have a prototype and costs this week as we discussed numerous differant methods of building the parts needed for this project.
Two more cases of the failure found in the last two weeks on local cars only so I need to get this into production right after we look into Steves thoughts. I expected everything in the car to work a little better as now it the whole car gets the correct voltages and current flows but it will not fix other components that are experiancing mechanical failures. Those have to be dealt with seperately as required.

The fusebox fix (we have to name this thing) installed on the Mondial T 2.5 Coupe just before your 2.7 Cab. experianced simular results as yours on his 1000 mile trip, everything just worked better throughout the car, the owner checked in early this week with the feedback. Yesterday I spent time working on the adaptations for the 328 and F40 as I have one of each in the shop now. It is due to the patience of numerous owners such as yourself that this has become a reality. That covers all the models and they are all doable albeit some offer up fairly cramped quarters that restrict the space I have available to work within and not have the mods seen when at all possible.

I have three other re-designs / upgrades "things" on the road being tested now for various models. This by itself has become a full time job and requires a good deal of effort. With the quality, cost and availibility of the parts we are now all getting, I feel spending time on these projects is justified now. The real trick is to keep it affordable and local so the quality of the parts never comes into question. It would be a little cheaper yet if I Sub'ed parts overseas but that would defeat my goals and requirements, we have enough of that going on already.

Stop by when you can,
Dave

 

I tried doing a search, but came up empty: Does anyone know a source for those white edge connectors (shells and pins) at the relay panel? (The cable side)

Also: what's the trick to extracting the pins from the shell? (Where's the release catch between the pin and the shell?) I tried all four sides, and only managed to crack the plastic shell (already brittle from cooking).


I may be missing something, but it looks like the "kit" replaces relays with connectors which then run to fuses. Are those relay positions open on other models, or is the relay function relocated elsewhere?


I've only had one pin burn like that on my 328 -- the instrument lights pin on connector "J" (top right horizontal connector in the car (fuses at the bottom), bottom left as shown in post 1 with the fuses at the top). (The connection from relay "o" and 15A fuse 16)

Unfortunately, it's happened *TWICE*. When it happened in '00, I had the connector replaced. I just had the relay panel out for some rewiring earlier this year, and that same connector fried again earlier this week. Okay, so it's nearly 15A through a tiny connector, carrying the instrument lights, running lights, and fog lights (I was using my fog lights as twilight running lights).

But I think the "smoking gun" is that it seems to be the connections that have two fat wires attached to the itty bitty pin. I suspect that the two wires, stuffed into the narrow parts of the panel space, pull too hard on the connector pin, causing it to have a poor connection, creating heat, etc etc etc.

In almost nine years, I've only had that one pin burn (albeit twice), so I'm thinking that I should replace the shell, and then splice one wire onto the two, and hook the one wire to the pin, so there's less strain on the connector pin.

Of course, to manage that, I'd need to find a source for the shell and pins.

Anyone know a source?

---
And the nerd said, "Let there be (running) light".
And behold, there was running light.
And the nerd looked at the running light and saw that it was never gonna last.

 

Sorry to wander off subject but I found the major cause of my slow and intermittent windows was LOOSE GROUNDS.
The resulting diagrams were the product of tracing the problem circuit by circuit.


Just to help everyone verify the window switch wiring on an early 308 using chassis ground.
All of these switches are mounted on the doors.
This is the drivers window switch wiring hook-up.
The ground was located in the lower forward corner of EACH the door frame.
Stock fuse block, fast windows.
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This is the switch that operates the passenger side window from the DRIVERS SIDE.
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This is the passenger side switch.
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