Defender Source Forum banner

1 - 20 of 30 Posts

·
Premium Member
Joined
·
7,172 Posts
Discussion Starter #1
Board restoration in progress. When I recieved it, it was pretty much encrusted in blue corrosion. Someone tried to clean it up using a scraping tool and did a lot of damage. I cleaned it chemically which helped reveal the extent of the damage. It wasn't pretty.
I reconnected the broken traces. Removed the integrated circuit near the battery as some of the busted traces were underneath. There are three breaks. One there in the middle you can see easily, then another just to the right and the third just above between the resistor and the IC holes. I will install a socket for the ICs so that they can be removed easily. Next step is to epoxy seal the card and install the missing parts.
You can also see there's a bad trace for the battery leg (the wider one) there near the black capacitor . I'm going to have to reroute that under the board with a jumper wire. The ground leg hole (center of pic) has some damage but I think it'll solder up OK. All in all not as bad as I've seen, but still a challenge. I'm using parts from two boards to make one good one. Super fiddly work bending the hair-thin wires and holding them in place to solder. I have to solder while looking thru a magnifier.
 

Attachments

·
Premium Member
Joined
·
7,172 Posts
Discussion Starter #4 (Edited)
Send it on up Mr C.
One thing that eats the traces is the corrosive acid which somehow finds a way under the green conformal coating. The coating has to be carefully removed and the acidy area neutralized so it doesn't get any worse. Then you can repair the breaks and recoat.
 

·
Premium Member
Joined
·
4,618 Posts
This is fascinating. Why repair in this case? The challenge?
Because these ecu boxes are unobtanium.
You lose drivers' seat function and control of the mirrors when the ecu fails.


.
 

·
Premium Member
Joined
·
876 Posts
Very cool, Bill. Most of my youth was spent repairing circuit boards for various electronics on navy ships and subs. I have a few of these ecu's in storage. maybe I'll look to fix a couple and provide for a nominal fee to those desiring one. Other than the memory function I see no use in this overly complicated ecu. All of the basic functions could be bypassed IMHO. I think some have done this very thing. I'm putting older vogue mechanical seats into my '90 rrc. The mirrors will be fused and maybe a simple load relay for operation.
 

·
Premium Member
Joined
·
13,823 Posts
Because these ecu boxes are unobtanium.
You lose drivers' seat function and control of the mirrors when the ecu fails.


.
Unless you live near Doc Nomar, he can rig ya up with a non memory seat switch and some adapter wiring and regain @ least the seat functions.
 

·
Premium Member
Joined
·
13,823 Posts
Send it on up Mr C.
One thing that eats the traces is the corrosive acid which somehow finds a way under the green conformal coating. The coating has to be carefully removed and the acidy area neutralized so it doesn't get any worse. Then you can repair the breaks and recoat.
Do you have a source for a replacement battery ? I know Joel found some and I haven't asked or even looked but batteries have come a long way since 1994.
 

·
Premium Member
Joined
·
6,562 Posts
Do you have a source for a replacement battery ? I know Joel found some and I haven't asked or even looked but batteries have come a long way since 1994.
There's a uk sell on ebay that sells the battery and separately the chip and most commonly failed parts on the RRC ecu. We just went through that. Greenbull used same seller and repaired his.
 

·
Premium Member
Joined
·
13,823 Posts
Couldn't you splice in part of a harness from an earlier RRC and just lose the memory function?
That's what Jeff/Nomar did for me. We took some harness out of an 89 parts truck I have and he made something that plugged into the existing harness and the seat now works, but no mirrors.
 

·
Premium Member
Joined
·
7,172 Posts
Discussion Starter #15 (Edited)
Doug they are very common batteries. I got them from Mouser. The only custom bit is the memory chip. Everything else is off the shelf electronics parts available from a gazillion sources. That said, usually the only thing that gets messed up are the capacitors that are in the battery's neighborhood.

------ Follow up post added September 16th, 2015 03:11 PM ------

Very cool, Bill. Most of my youth was spent repairing circuit boards for various electronics on navy ships and subs. I have a few of these ecu's in storage. maybe I'll look to fix a couple and provide for a nominal fee to those desiring one. Other than the memory function I see no use in this overly complicated ecu. All of the basic functions could be bypassed IMHO. I think some have done this very thing. I'm putting older vogue mechanical seats into my '90 rrc. The mirrors will be fused and maybe a simple load relay for operation.
The problems are specifically related to the two position memory seats and not the non memory seats. I think they are 93-95 LWB specific, but probably were also on any County model from that time frame.
You can swap out the memory ECU for a non memory ECU, along with a non memory mirror switch and be OK....I think.
 

·
Premium Member
Joined
·
522 Posts
Very cool. I didn't know the ecu was repairable.

Out of frustration I rewired my seat using an earlier RRC switch. If you use a Disco I mirror switch, you can get the mirrors to work. The mirror switch looks the same as the Disco switch but it is different. For some reason the rear wiper switch in my '95 lwb is on the same circuit as the ecu and I had to get power to the relay but everything works now.
 

·
Premium Member
Joined
·
15,221 Posts
I fixed mine with just a battery. Anyone with any of these trucks should replace the battery as a precaution and repeat every ten years.
 

·
Premium Member
Joined
·
7,172 Posts
Discussion Starter #18 (Edited)
OK tested the repaired board last night. Had to undo my own front seat (!!!!) to access the connectors so I could plug it in to the LWB wiring. 99 percent success. Well, maybe not exactly 99%. Memory function in both setting 1 and 2, and the seat motors and mirrors function properly. The relays for the seat back recline function operate (board is out of the case so I can see them clicking open and closed) but the seat back is not reclining. Well, actually it did for a couple of tries then stopped. I suspect this one relay on the board is faulty so I'm going to replace it and retest this evening.
Those relays are a HUGE PAIN IN THE ASS to desolder and remove without ruining the trace on the top surface of the PC card. They are a big hunk of copper so they soak up all the heat from your iron, making it difficult to get all the old solder out. Even my big Weller iron is having some difficulty, and the solder wick is not soaking up the wet solder. Then there is a very slight amount left topside that you just can't reach.....
 

·
Premium Member
Joined
·
7,172 Posts
Discussion Starter #19
Swapped out bad relay. Everything tested out 100% completely functional . Considering that these things are super rare in operating condition, ol Dread got himself a smoking deal on a working unit. But I'm in it for the love not the money....
Dunno if it would be considered upgrades but two things I did that help is put in a 150 mA battery instead of the 100, and install the new integrated circuits with socket plugs instead of direct to the card.
 

·
Premium Member
Joined
·
534 Posts
Wow, I missed all the progress and pictures. Feel a little famous now. :hide: Thanks Bill. U R D MAN!

FYI, I hope you're in the mood for some more love, because I'm referring like 6 guys to you with probably the same problem

Thanks again man
 
1 - 20 of 30 Posts
Top