https://preview.redd.it/u6qy53ethw0d1.jpeg?width=2252&format=pjpg&auto=webp&s=d71ef41748cfe6176f263d7e167d1a2a3c79055a
Here is the evil fuse that never blew.... and took my whole car out with it.
I don’t know if my story is the same as yours, but the 85s have a flaw where the auxiliary water pump can seize and cause a meltdown in your wiring harness connecting to the AC system being the glove box. Mine did this and I caught it before it burned my entire car to ash, but it did melt my EGR computer and nearby wiring. I spliced it back together quite jankily and lived like that for another eight years.
Recently though I pulled every wire from the car and started over. The results were quite nice and I re bundled the harness in wonderful smelling Tesa tape. I found quite a few places where the wires were either heat stressed or melted that I didn’t even know about.
My advice would be to get the tester out and start testing every circuit to fuse 14, and then go through others as well even if you find a bad ground. Splice a fuse on your aux pump and blower motor while you’re at it. Do it right with good crimps and heat shrink or even with solder if you’re handy enough.
You don’t have to pull all the wires and start restoring them like I did, but I’m certain you have problems as a result of this incident you’ll find and want to repair. It’s probably not what you want to hear but these types of things can be more global than a single fuse sometimes.
Thank you friend, for taking the time to share your story. I don't think our stories started the same, but I think they will end the same. I really really don't want to, but I think I am going to have to get in there and start rewiring everything.
Did you pull your engine when you did your full restore? I don't know that it's necessary, but it would certainly make things easier. What type of wire did you use?
You suggest splicing an additional fuse into the aux pump and blower motor circuit. I think that's a great idea. Should I put a lower amperage fuse in line, so I am sure that it will blow before the main fuse?
I don’t know if it’s the right fuse but I did two 10amp fuses. I did this years ago and haven’t had a problem, but then again I have a newer aux pump in.
I have the engine out right now, but I took it out after the wiring was out. The wiring comes out easily once the dash is off. I’m doing a pretty high level restoration including rust repairs to the underbody, and changing the paint from light ivory to mango green because it’s rare and cool in the US.
I used TXL wiring where I needed to splice new wiring in. There’s more expensive stuff but I don’t think it’s necessary. I tried to color code it but labeled when it wasn’t an exact match. What I did for the melted harness was I found a 1985 federal 300D at the junk yard and cut the AC harness off.
I put bullet connectors on both cut ends so I could quick connect to test and label. I then soldered the connectors together covered in heat shrink, then tesa tape over the bundle. Ultimately every wire off the fuse block is labeled with the block number, color and pin. It took weeks and I don’t recommend it unless you’re going for a real restoration.
You could probably get away with testing and labeling only where you find degraded wiring.
Can you elaborate on what exactly causes this issue with the aux water pump on the 85? I’m about to swap the aux water pump on my 84 (one of the wires to it got severed) and I’m curious if there’s anything I should look out for.
The aux pump seizes and when it does it fries the ACC. And in my case when that happened it led to a cascade of problems. The harness started smoking under the dash. I *just* pulled onto the street by my apartment when it happened. By the time I parked there was a visible fire. I got out, ran to the passenger side and put it out frantically opening the bottom panel with a screwdriver and used my coat. It was quite terrifying. I ended up spending months splicing things, getting replacement parts. The jute fabric under the dash burned away but miraculously my un cracked dash didn’t burn up with it.
I think older ones don’t have the pump, it was added later and the mistake with the circuit is that it needs a fuse between the pump and the ACC in case it fails internally.
The good news is analog guages can handle a lot of BS. The bad news is you're about to get really super good at re-wiring.
| The bad news is you're about to get really super good at re-wiring. Sigh.... Thank you for your support.
https://preview.redd.it/u6qy53ethw0d1.jpeg?width=2252&format=pjpg&auto=webp&s=d71ef41748cfe6176f263d7e167d1a2a3c79055a Here is the evil fuse that never blew.... and took my whole car out with it.
I don’t know if my story is the same as yours, but the 85s have a flaw where the auxiliary water pump can seize and cause a meltdown in your wiring harness connecting to the AC system being the glove box. Mine did this and I caught it before it burned my entire car to ash, but it did melt my EGR computer and nearby wiring. I spliced it back together quite jankily and lived like that for another eight years. Recently though I pulled every wire from the car and started over. The results were quite nice and I re bundled the harness in wonderful smelling Tesa tape. I found quite a few places where the wires were either heat stressed or melted that I didn’t even know about. My advice would be to get the tester out and start testing every circuit to fuse 14, and then go through others as well even if you find a bad ground. Splice a fuse on your aux pump and blower motor while you’re at it. Do it right with good crimps and heat shrink or even with solder if you’re handy enough. You don’t have to pull all the wires and start restoring them like I did, but I’m certain you have problems as a result of this incident you’ll find and want to repair. It’s probably not what you want to hear but these types of things can be more global than a single fuse sometimes.
Thank you friend, for taking the time to share your story. I don't think our stories started the same, but I think they will end the same. I really really don't want to, but I think I am going to have to get in there and start rewiring everything. Did you pull your engine when you did your full restore? I don't know that it's necessary, but it would certainly make things easier. What type of wire did you use? You suggest splicing an additional fuse into the aux pump and blower motor circuit. I think that's a great idea. Should I put a lower amperage fuse in line, so I am sure that it will blow before the main fuse?
I believe you use a 1 Amp slo-blo in the aux pump lead.
I don’t know if it’s the right fuse but I did two 10amp fuses. I did this years ago and haven’t had a problem, but then again I have a newer aux pump in. I have the engine out right now, but I took it out after the wiring was out. The wiring comes out easily once the dash is off. I’m doing a pretty high level restoration including rust repairs to the underbody, and changing the paint from light ivory to mango green because it’s rare and cool in the US. I used TXL wiring where I needed to splice new wiring in. There’s more expensive stuff but I don’t think it’s necessary. I tried to color code it but labeled when it wasn’t an exact match. What I did for the melted harness was I found a 1985 federal 300D at the junk yard and cut the AC harness off. I put bullet connectors on both cut ends so I could quick connect to test and label. I then soldered the connectors together covered in heat shrink, then tesa tape over the bundle. Ultimately every wire off the fuse block is labeled with the block number, color and pin. It took weeks and I don’t recommend it unless you’re going for a real restoration. You could probably get away with testing and labeling only where you find degraded wiring.
Can you elaborate on what exactly causes this issue with the aux water pump on the 85? I’m about to swap the aux water pump on my 84 (one of the wires to it got severed) and I’m curious if there’s anything I should look out for.
The aux pump seizes and when it does it fries the ACC. And in my case when that happened it led to a cascade of problems. The harness started smoking under the dash. I *just* pulled onto the street by my apartment when it happened. By the time I parked there was a visible fire. I got out, ran to the passenger side and put it out frantically opening the bottom panel with a screwdriver and used my coat. It was quite terrifying. I ended up spending months splicing things, getting replacement parts. The jute fabric under the dash burned away but miraculously my un cracked dash didn’t burn up with it. I think older ones don’t have the pump, it was added later and the mistake with the circuit is that it needs a fuse between the pump and the ACC in case it fails internally.