RobzWorkz #6(66)a: Enjoying the Electrical Demons: Relay Board Renewal

Hello again, FChat!!!

I have been busy with my '87 328 over the last couple of years and publishing the RobzWorkz series for all of us to enjoy. I am now up to RobzWorkz #6(66). This time, I reserved the #666 (the 6(66) in the post title) for addressing the pitfall of all older-car ownership: the dreaded electrical demons! They show up all the time, and, unless one replaces all the wires, relays, connectors, switches, bulbs, ECU's and boards in the entire car, they don't really go away.


INTRODUCTION:
When I first got the car (for an excellent price indeed!!!), I expected the worst: no startup, flippy-lights, a small fire, etc. However, when I picked her up from the delivery guy, she started and ran very well; the drive home was enjoyable; the only drawback was that the fog light assemblies were removed and I had to install some alternates (BTW, I plan to re-design a new set of fog/signal light assemblies anyway since the old ones are prohibitively expensive and are simple enough to reinvent). Other than that, I only had some glitches with the lighting and some of the peripheral stuff; the engine ran well enough to enjoy some driving before my renewal efforts began. I certainly do enjoy a project!

Over the time, I replaced many bulbs, fuses and relays, and did pre-emptive cleanup of various switches to keep the car running well while doing the other restoration efforts: please review the RobzWorkz series at your leisure. Now I have begun to attack the electrical demons with enough determination to enable my enjoyment of the car for several years, while only needing to conduct simple preventative maintenance of the electrical system. Although it is my endeavor--several years from now--to re-design the entire car's operating system with modern methods, these RobzWorkz 6(66) posts are only for demonstrating the rehabilitation the current, outdated, design of the vintage 80's system.

Since I am refurbishing all of the operational electronics of the 328, I think it venerable to begin with the largest demon of them all: the relay board and its connectors. This post will only deal with the relay board...the connectors will be next (6(66)b). As an example of the demonic nature of the 328 relay board, I submit to you that I enjoyed better all-around operation of my 328 when I dismounted the relay board from under the dash and let it hang by the wires (the dash panel removed): my lights worked better than ever, even after cleaning/replacing bulb sockets and cleaning the stalk-switch mechanisms. I also read in several FChat posts about the relay board/connectors posing several problems. It is well-established that the compacted area under the dash is unsuitable for for the board and its connectors; the assembly heats up with the significant current and the wires in the connectors are pressed to cinching. Thus the area gets hot and deformed and the electronics suffers.

Therefore, my effort will basically rebuild the entire relay board, clean/replace and test relays and fuses as necessary, and test the board as a whole. Additionally, I will refurbish the connectors/wires and relocate the relay board to a location where there is less wire stress and heat can be better liberated.

BTW, since acquiring the 328, I found it worthwhile to completely remove the heating and AC system (in its entirety; pieces are available, just PM me for a part). Although novel in design in its day, with its nifty two-passenger controls and such, the technology is inferior enough by today's standards to warrant a redesign (a future endeavor). Thus, since removing the AC evaporator assembly and associated ducting, I now have a sufficient area underneath the passenger dash to relocate the relay board there: when finished, the relay board assembly will be as new, and there will be less stress on the connectors and heat will dissipate very well.


REBUILDING THE RELAY BOARD:

First, some very important caveats:

1. IF YOUR RELAY BOARD WORKS, DON'T MESS WITH IT: you can take it out and open it up and clean it with alcohol...even clean and insulate the connectors, relays and fuses, but that's about it. If it works well enough, keep it, love it, and leave it alone...you are very blessed, and will not be able to improve it anyway.

2. The relay board is a design incorporating a flexible, five-layered, through-soldered curcuit board. If you try to disassemble this board, you will destroy it...it is not repaiable by an amature: desoldering this item is not possible without significantly degrading it. Thus, if you desolder this board, be sure you are fully-committed to rebuilding with other means or with replacement: I was fully-committed and de-soldered the board, used the layers for reference and rebuilt it with solid core wiring.

3. Rebuilding the board with wire soldered into position is not simple: if you have little or no experience with soldering, don't try this effort...just enjoy the post. I am a professional at soldering various items from electronics to stained glass and very am confident in my abilities. Also, as I did, be sure to practice a little prior to doing the actual work. Be sure to tin material before final soldering. For this effort, I used a 30 WATT SOLDERING IRON with good results.

4. Use only SOLID CORE WIRE in the relay board rebuild: when soldered, stranded wire wicks in fluxes and other impurities which will aid in corrosion and deter from good electronic performance. Because of its flexibile property, stranded wire is essential when routing through and around obsticles; inside the relay board assembly is not this type of environment. BTW, most effort with stranded wire involves crimpimg vice soldering.

5. Clean and re-clean; solder and re-solder: when I solder large electronics (wires like this are large, unlike circuit chips and smaller components), I clean it, solder it, clean it, solder it, and repeat until I get a good shiny uniform solder joint. Some older material, like the relay plugs, will require multiple efforts to properly solder.

6. Use separate color wires for each layer of the relay board: I got my wire at Home depot...12 gauge solid core, with five different colors, one for each layer. This is important, especially if you have to go back later and repair.

7. Be sure to have retrieved the circuit diagrams. Much of the basic diagrams for the 328 and others, are available for free download.

8. After the rebuild, depending on your quality and thickness of work, reinstalling may be a challenge if returning to its original position behind the passenger dash panel. So, first, consider relocation (rewiring the connectors is essential for this); if not, reinstalling may require removing the tabs on the top of the board (mine did) and using longer screws for installation.

9.Finally, take your time...this is a project, not a lifestyle. Enjoy your effort and its rewards.


FIRST STEPS:
1. Car is OFF.
2. Disconnect the battery.
3. Remove the passenger dash cover...two finger bolts.
4. Remove the screws holding the relay board in place. It should hang after helping it out from behind the dash.
5. Disconnect the connectors: I use a long medium-sized flat blade screw driver. It's easy once you do this a couple of times.
6. Disassemble the relay board.
7. Clean the board and its components with 90% or greater rubbing alcohol (get at drug store).


NOW FOR SOME PICS:

Pic 1 shows the relay board as an assembly; note, I had installed some cheap relays to use during the rebuild. The proper relays are metal-boxed Bosch and are awaiting testing and refinishing, to be done later. Pic 2 is of all the relays and fuses taken out and the screws holding the relay board in place. Pic 3 is a display of disassembled stuff. Pic 4 shows the fuse, relay and connector pins/terminals, all to be refurbished. Pics 5 and 6 show the relay board circuit board assembly, awaiting desoldering. Pic 7 shows the terminal board with the relay terminals fully-removed; fuse box areas were also removed; I kept the connector terminals in place though. Pic 8 shows the circuit board desoldered and separated.
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FYI, the terminals to which the relays attach are way too thin, just single little wires attached to the relay board itself. To allow proper current and mechanical stability, I re-fashioned them with finishing nails. The nails are thick enough to provide for good current and mechanical strength while being able to be tinned with solder. First, solder the relay terminals to the finishing nails. To properly install, place within the terminal board with relays themselves and begin soldering the wires to them from below.

PICS:
Pic 1 shows how each terminal has a finishing nail soldered to it. Pic 2 shows placing into the terminal board with a relay attached; this is essential to allow for proper alignment of relays to the board; do this with all relay positions. Pic 3 shows the upside-down view of the terminal board with all relays and terminals in position, ready to begin soldering with the solid core wires.Pic 4 shows the top view with all the relays in position. Also note the six terminals that are "floating" but useful to the wiring of the board.
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I've decided that I would show one layer soldered-in for one post; this will be done with pics in each.

Pic 1 shows bending a white wire associated with a current path on Layer 1. Pic 2 shows Layer 1 assembled. Note that it still has flux present. All will be cleaned after all layers are installed.
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Layer 2 is blue, shown with its circuit layer.
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Layer 3 is red, shown with its circuit board layer. You can see one black line from Layer 4 installed; this was necessary for proper fitment; you will notice this type of predictive assembly as you progress, hopefully.
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Layer 4 is black, shown with its circuit layer. This view is of the board rotated 180 degrees from the previous post.
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Layer 5 is green as shown.
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It is very important to clean all the flux and other impurities from the completed board. This can be done with 90% or greater rubbing alcohol purchased from a drug store and scrubbed with flux brushes and wiped with paper towels. Also, I used a rotating brush attachment on a Dremel tool for cleaning.

To test the circuit assembly, use an ohm-meter; one with a continuity sound checker is a good choice.

Pic 1 shows me cleaning soldering points with the Dremel tool. Pics 2 and 3 show me "ohming-out" the board. All was well with this effort board thus far. Pic 4 shows the assembly with the cheap relays in place, ready to refurbish the originals.
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When I acquired my 328, I was fortunate to have all of the original relays. However, they were unsightly, but still working. Thus, I sought to refinish them, test them, and install for an original look and operation. Also, I chose to paint the ingraved lettering on each Bosch relay a certain color so as to identify them quickly. Recall, there are three types of Bosch relays installed on the relay board. Please refer to the owner's manual to identify. To apply the color, I pained the top of a relay with Testors enamel paint, let dry, then sanded off with an emery board; I used the emory board to shine-up the relay boxes as well.

To test a relay, I used an 11.1V battery used for RC airplanes and such to toggle the relay while monitoring for continuity of the relay circuit.

Pic 1 shows the painting effort to color the relays. Pic 2 shows a "before-and-after" comparison. Pic 3 shows the setup used for testing the relays. Any relay that didn't switch was replaced with a new one (generally purchased off of ebay).
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To finish, install all relays in their proper locations (use Owner's Manual as a guide), install proper fuses, and install the relay board connectors and the board itself in the passenger side of the dash. After installing, I tested and all went well. I still noticed some glitches, which was expected: I knew the connectors needed refurbishment. This will be the next installment of the RobzWorkz series.

Pic 1 shows the installed, refurbished relay board. Pic 2 shows with the dash cover installed.

Next effort: the relay board connectors.

Enjoy FChatters!!!
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Rob,

This is truly amazing work and your very helpful post has inspired me to rework my own (charred) circuit board. I have managed to separate the five layers, and now the rebuild begins.

I hope that I can emulate your success.

Guy

 

Love your work, Rob. Thanks for taking the time to document and photograpm your progress.

 

Thanks!

These replies are my sources of inspiration.

 

That's an amazing bit of work Rob - I hope I never have to do it!

 

After losing a horn, a fuel pump, and enduring a sunny drive from SF to LA with no radio and the heater stuck on full blast, I decided I had enough of the electrical gremlins in my relay board.

Rob sure let the genie out of the bottle here! He isn't kidding about this being a one-way process. The circuit boards are quite brittle. My attempts to gingerly deconstruct them resulted in an office reeking of burnt plastic and a pile of Swiss cheese that used to be expensive Italian electronics.

To pay homage to Rob's work, I felt it worthy to invest a little time and fully document this deconstruction. I've used my fancy plastic calipers and some free CAD software to map out the relay board, one layer at a time. These drawings can be used to make laser-cut duplicates of the relay board should one need a replacement... I've learned to plan to screw-up before actually screwing up, so it's not as painful.

I'm also nipping the "molten connector" issue in the bud by ditching the existing connectors for 50A Molex connectors. This will require rewiring all the harnesses, but in comparison to rewiring the relay board, this is small potatoes

Now that deconstruction is done, it's construction time! I'll post some pictures as I progress.
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Wow, amazing work! I dont know if I have the patience to do something like this. Well done.

 

Thanks, guys!

FYI, I did a connector enhancement and board relocation as well:

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

BTW, maestro8, do the 50A Molex connectors come in like sizes as on the board?



My recommendation is for someone to do this kind of rework only when his/her car starts going down the electron tubes. This type of fix works well but requires significant commitment and still may fail over time. That's the main reason for relocating the board: with less heat stored, the board should last significantly longer.

The combination of the relay board rebuild, the connector rebuild and relocation is not the optimum fix. Although it will provide several years of gremlin-free operation, it would be best to fully redesign the 328 (and others) layout so as to have relays located near their current loads and only relay control currents present in the interior. I plan to do this one day, but, for now, my fix will work just fine.

A good interim fix would entail designing a board as designed but with better current handling. Using two 2-sided and one 1-sided PCB's with thick copper conductors could work without making a true "multi-layered" board (I wouldn't encourage building a true mult-layerd board because the currents are high and the board would fail). Basically, the three boards would be electrically isolated (rubber sheets) and only vias with conductors would connect to the relay plug terminals.

Enjoy!

 

Rob, great work!

All I can do is just sit and watch you do your magic.

You are Master of your Domain.

 

Unfortunately, they don't. Only up to 6 conductors in a single row, 12 conductors in a double, and that's all!

I've searched through Mouser and Digikey's catalogs, and checked with a couple specialty distributors (such as http://www.wirecare.com/deutsch-connectors-main.asp), and this is the highest-density high-amperage connector I can find.

I realize I could use lower-amperage connectors for some circuits, or even reuse the existing connectors, but I wanted to go all or nothing on this fix.

 

Alright! I've got my "road map" complete and am on my way to electrical happy-land.

Or, at least I hope.

I've put my order in for connectors and gold pins. At a buck a piece (remember you need a male and a female for each circuit!) that's over $150 just in pins.

$150 may seem steep for pins, but in comparison to a $1k bill for a NOS board and unobtanium stock connectors, it's a steal!

Now the soldering begins...

Edit: I'm more than happy to share my source file. It's in AutoCAD format (DWG) and can be used to produce new boards from blanks if you have the right equipment!
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A

 

my blower switch does not shut off on my f355 it works high and mideum speed i no its the unit otherwise it wouldnt work on 2 speeds does anyone no wrer i can send it out to get fix the curciut board

 

Sorry, I can't help for a 355. Please go to the 348/355 forum and try there. Ernie is doing some excellent work there.

BTW, welcome to FChat!

 

Jason,

Good work with the CAD drawing!

This is for a Mondial3.2, right?

If so, please show board work there and link to it from here. It will reduce confusion since the 328 and Mondial 3.2 are different.

(please provide link updates here when you post there as well...it's awesome so see original developments)

 

Yes, I should be putting this in the Mondial forum... I've only gone through the deconstruction and reverse-engineering process so far, which hasn't differed from your work.

But going forward, engineering the new connectors and reinstallation will be Mondial-specific. So a new thread it will be!

I just wanted to make sure you got credit for my inspiration...