Wiring harness - where does it go?
08-31-2015, 10:46 PM
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Wiring harness - where does it go?
Having a 1989 944 NA I tried the alarm delete procedure in Clark's Garage, not realizing that the instruction to jumper pins 1 and 4 in the alarm brain connector is wrong for me. One jumpers alarm brain connector pins 1 and 3 on my car, as the wiring diagram for the 1989 model does in fact confirm. (One also jumpers pins 4 and 5 in the G19 relay socket for the 1989 model, just to make this story complete.)
So ...
I then did it the right way but the first erroneous effort had fried a wire - specifically a black wire with a white stripe at the alarm brain connector end. Its still connected, but the insulation is melted.
Car went 40 miles with the delete jumpers in place and then quit. No fuel. Engine stopped four times. Restarted three times. Then nothing. I can make the fuel pump run by jumpering pins in the DME relay socket, so the fuel pump is OK. DME had just been rebuilt by ECUDoctors. I sent it back to them where Jorge graciously retested it for no charge and pronounced it sound. So the DME is OK.
Looked closely at the alarm brain plug and discovered the charred wire. On advice from the internet I pulled up the fuse/relay panel under the hood and looked for damage underneath. I found the other end of said charred black wire with a white stripe. Confirmed its the same wire with my trusty continuity tester that lights up. Its the same wire, and its intact, but its more melted at this end than the other.
Sat and stared at the car for two weeks, resisting the conclusion that I must get inside the wiring harness and fix all the damage this thing did. I lost that battle, bought a used Volvo V70 to get around in, and set out to trace the bad wire all the way and find what else it had melted.
Feeling like a med school surgery student performing his first appendectomy I gingerly cut into the harness wrapping and started tracing the wire from underneath the fuse/relay panel under the hood, pulling the wire bundles apart and marking them with zip ties as I went. Found a few inches of three wires melted to the bad wire. Pulled them apart and I think I can repair the damage to the others with a drop or two of liquid electrical tape.
Went deeper into the abyss and some of the wires in the bundle I was tracing branched off and went elsewhere, leaving only three wires headed toward the passenger footwell, where the alarm brain dwells next to the DME. These are the damaged black wire with a white stripe, a light blue wire and a fat red wire with a white stripe. Went around the car and back down into the passenger footwell, and behold, there next to the ragged black wire with the white stripe are a light blue wire and a fat red wire with a white stripe.
By now I've flayed the harness open from the top as far as I can see, and am close to where I'll be working by feel. This bundle crosses under the dash behind the radio (I guess) to the passenger footwell where I can see it again.
What I need to know is whether I can pull the radio and get at the invisible section that way, or whether I can worm my way up under the dash and follow it that way. What I'm trying to avoid, of course, is pulling the dash. I'm not a mechanic and I'm not as young as I once was so I will probably have to pull the seats in order to be able to lay on my back and reach up under the dash to get at the rest of the harness. Anything but the dreaded job of pulling the dash.
Any suggestions will be appreciated.
As an aside, I like the Volvo, its a very smooth car, and very nice, but to paraphrase Governor Schwarzeneger, (sp?) its a girly-car. I want my man-car back !!! (Boost-guys, please, my NA is SO a man-car. I'm 76. Its all the man-car I can handle.)
TIA
PS If I HAD gone to med school, I would not have to be doing this. I could either hire it done or just buy a new Porsche. Alas, I did not go to med school and so I have to fix this myself or do without my Porsche. That I am not willing to do.
So ...
I then did it the right way but the first erroneous effort had fried a wire - specifically a black wire with a white stripe at the alarm brain connector end. Its still connected, but the insulation is melted.
Car went 40 miles with the delete jumpers in place and then quit. No fuel. Engine stopped four times. Restarted three times. Then nothing. I can make the fuel pump run by jumpering pins in the DME relay socket, so the fuel pump is OK. DME had just been rebuilt by ECUDoctors. I sent it back to them where Jorge graciously retested it for no charge and pronounced it sound. So the DME is OK.
Looked closely at the alarm brain plug and discovered the charred wire. On advice from the internet I pulled up the fuse/relay panel under the hood and looked for damage underneath. I found the other end of said charred black wire with a white stripe. Confirmed its the same wire with my trusty continuity tester that lights up. Its the same wire, and its intact, but its more melted at this end than the other.
Sat and stared at the car for two weeks, resisting the conclusion that I must get inside the wiring harness and fix all the damage this thing did. I lost that battle, bought a used Volvo V70 to get around in, and set out to trace the bad wire all the way and find what else it had melted.
Feeling like a med school surgery student performing his first appendectomy I gingerly cut into the harness wrapping and started tracing the wire from underneath the fuse/relay panel under the hood, pulling the wire bundles apart and marking them with zip ties as I went. Found a few inches of three wires melted to the bad wire. Pulled them apart and I think I can repair the damage to the others with a drop or two of liquid electrical tape.
Went deeper into the abyss and some of the wires in the bundle I was tracing branched off and went elsewhere, leaving only three wires headed toward the passenger footwell, where the alarm brain dwells next to the DME. These are the damaged black wire with a white stripe, a light blue wire and a fat red wire with a white stripe. Went around the car and back down into the passenger footwell, and behold, there next to the ragged black wire with the white stripe are a light blue wire and a fat red wire with a white stripe.
By now I've flayed the harness open from the top as far as I can see, and am close to where I'll be working by feel. This bundle crosses under the dash behind the radio (I guess) to the passenger footwell where I can see it again.
What I need to know is whether I can pull the radio and get at the invisible section that way, or whether I can worm my way up under the dash and follow it that way. What I'm trying to avoid, of course, is pulling the dash. I'm not a mechanic and I'm not as young as I once was so I will probably have to pull the seats in order to be able to lay on my back and reach up under the dash to get at the rest of the harness. Anything but the dreaded job of pulling the dash.
Any suggestions will be appreciated.
As an aside, I like the Volvo, its a very smooth car, and very nice, but to paraphrase Governor Schwarzeneger, (sp?) its a girly-car. I want my man-car back !!! (Boost-guys, please, my NA is SO a man-car. I'm 76. Its all the man-car I can handle.)
TIA
PS If I HAD gone to med school, I would not have to be doing this. I could either hire it done or just buy a new Porsche. Alas, I did not go to med school and so I have to fix this myself or do without my Porsche. That I am not willing to do.
