Some guages quit working 1988 328

I was driving and the speedometer quit working along with oil temp, water temp and oil pressure gauge. Tach, clock and gas gauge were working. At a stop light it was idling a little uneven but not bad. When I got home I turned it off then tried to restart and the lights went on but no noise or click from starter. All the lights were bright. Turn signals, wipers and lights work. Any ideas?

 

Sounds like a main / common chassis ground failure ---- IIRC, all those gauges you mentioned (that quit working) are grounded through the engine casings, and then returned to battery (-) via ground straps connecting the engine block to the frame --- also, the (-) terminal on the starter serves as a primary ground path for many things.

I would check the engine-to-frame ground strap(s) and the cable from the starter(-) terminal all the way to the battery. My guess is that you will find a loose, or corroded, connection / damaged cable there somewhere. Sometimes, the braided ground strap (engine-to-frame) breaks all together --- leaving an open-circuit failure at that location.

 

Thanks, I'll give it a look

 

Or....fuse box failure. Search this forum for details...it's ugly...and I hope this is not your situation. If it is, consult with Dave Helms at Scuderia Rampante.

 

Sorry to hear about this problem John.
It would be real nice if you could get an opinion from Paul_308 on this?

 

I discount a ground fault as exactly and only those gauges plus the speedo sensor are fed from one fuse, third from left, on the printed circuit fuse panel. A ground would affect other items as well. Unfortunately, the 328 is known for intermittent faults to occur in that panel and a fix is painful.

 

If this has not been done elswhere I would volunteer to reproduce any printed circuit boards. There would be a minimum to bring the costs down per board but the layout work would be free. I would need a schematic or better yet a board, good or bad to reproduce.

 

Interesting about the PWB....

What about his starter not working --- separate issue, then?

 

If that happens its REALLY bad because this is the ground return for the starter motor. So the entire 300 amps-plus of current tries to find its way through alternative ground paths such as the throttle cable or assorted small wires in the harnesses. This can result in quantities of smoke if the starter is run for any length of time! The gauge problem would be the least obvious of the issues!

 

Yes, it can be an ugly scenario --- if it is a "total" open, fortunately though it usually is just a "partial" failure (not completely broken).

I definitely agree with checking out the PWA / fuse possibility as has been suggested by Paul. But, John also has the "uneven idle" symptoms he described ---- which makes wonder if there isn't some other, more generalized, electrical problem going on......

I'd check / rule out the basics first, before exploring the more "exotic" possibilities .

 

I pulled the 7.5 amp fuse, third from the left, and it tested good
When this happened I was about 5 miles from home and noticed the idle was not as smooth as normal at the stop light 2 miles from home. There was no electrical overheating odor. Could a relay be causing this? The lights in the dash light up when the key is turned just as they normally do but when it is turned further to activate the starter nothing no click just silence and the dash lights or interior light don't dim

 

Ignition switch / relay?

 

Here is the circuit for the starter. The voltage to engage the starter goes directly from ignition switch to the starter and doesn't pass through the fuse/relay box so it isn't a part of 'lack of click' problem.

Idle problem can be fuel pump as it's a common problem with the 328 to loose voltage due to burnt connector at the fuse/relay box.

Sounds like the car caught a direct hit from a solar flare.
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Yeah, you know folks, this is kind of a weird one (as electrical faults often can be).....

It may very well be the case that you (John) have more than one, and totally independent, electrical problem going on simultaneously ---- related to one another only by coincidence of timing.

Welcome to Italian cars !

 

Here's my refurb of the 328. I have the old floppy boards:

http://www.ferrarichat.com/forum/showthread.php?t=312775&highlight=RobzWorkz

 

John if after reading the great work above and you end up looking for someone to do this for you send me a PM. I have a soldering station and can do this level of work with no problem. I hope that you don't really need this much intervention.

myrob1, I did not know that this was a multilayer board. I am limited to having two layer boards made up. Your solution is simple and elegant. Well done. If you could scan each layer with your drawings and post it, then it would speed up reproducing your work. If you feel up to it.

 

It's 5 boards. You could do two 2-layered and one single layered with insulation in-between. It will be a challenge to align and connect the dots between boards, but that should be a single design effort. I don't know what Dave Helms does for these, so check with him first (no need to reinvent if done).

BTW, I would just mail you the flex boards and you can return them after you set-in the design. You will need the proper dimensions to fit into the normal enclosure.

 

My cad software only handles 2 layers. Any more then that and my head hurts (too old). I was just thinking about helping out John this time around since I had no clue it was this complicated. John doesn't live too far away. I thank you for your offer and depending on what if at all I hear from John I will be in touch.

I was tossing the idea around using multiple boards but the fabrication would be the PITA putting it all together in a small space. I would end up with something similar to the original in order to have enough trace thickness and we already know how well that doesn't work. I am wondering if the cad software might be able to take the schematic and redesign the board into just two layers. Any clue as to where I might find a 328 schematic?

 

Thanks for all the help. Given the complex nature of electrical problems I have decided to send the car to Competizione who does the work on my car and have it fixed. I will keep everyone updated as I get info. When I called them and explained my symptoms they were perplexed and suggested the same things as mentioned in this thread from ground to fuse panel to solar flares. Well maybe not solar flares but maybe corona mass ejections. Kind of sucks since October is great driving weather in my area. Thanks for all the help and to Bob for helping to do the circuit board. Does Dave Helms have boards for the 328? On his site it just states working on it or in progress. I don't know if it has been updated. I used his fuel lines for my major done

 

As I understand the Helms solution, it involves plugging into some relay sockets with an additional add-on box. This may only be an interim solution he has found, but it's the only kit-fix I've seen published. Realize there may be something later than this and that he is interested in a solution for more models than the 328.

http://www.ferrarichat.com/forum/showpost.php?p=138010471

An interesting approach.
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I have to say that myrob1's solution for the board rebuild is excellent. However, if there are issues before the board then they need to be addressed as well or even this fix may be limited in duration. I see perhaps a melding of the solutions to the underlying problems with the mechanical rebuild of myrob1. I put forth the Rob/Helms electrical dilemma solution challenge. May the force be with them.

 

Had the same problem: no starter, no gauges.
There are two multi-connectors sitting above the inner protectionshield (rear wheel) on the driverside. They transport al the signals from motor to dashboard. Also the ignition signals to the Digiplex.
Remove shield and pull connectors. Check and clean. If burnt ore oxidated: replace or bypass.

These two connectors are really important and check/treat them (WD-40) at least once a year.

Also a very important connection is sitting in the radiator-bay.
It is the well known battery-switch. By cleaning the connector itself: no improvement.
Lose and remove the nut holding it to the chassis and treat it with cupperpaste. Clean surfaces.

These actions wil help you to make your car more reliable.

 

FYI,
I also rebuilt my connectors...and relocated the board altogether to minimize heat buildup...

http://www.ferrarichat.com/forum/showthread.php?t=313441&highlight=RobzWorkz

The 328 electrical panel (along with other older-technology cars) were designed so that actual operating currents were present throughout the entirety of wiring harnesses, relays, and connectors. Modern designs are set up so that primary currents are more localized and that relay control currents are distributed from control switches at smaller currents to the relays controlling the larger currents. Newest designs incorporate ECUs to assess operation and diagnose failures.

The best method to enhance the 328 (and others) is to redesign altogether.

 

Note: Superperformance is listing the fuse board PCBs in stock.

 

See bottom of page.

http://www.superformance.co.uk/a-328/electrical.htm

$1500USD!!!

Pocket change...

And you still have to solder it into the board (all the relay and connector connections too)