Auto trans cables

[Andy_]

Hi guys, i removed my exhaust and have found the 2 thick cables and vac hose have been melted by the catalytic converter. I was going to open up the insulation and solder in new cables between the governor and transmission. Does anyone know how many wires run in each bundle ?
Thanks

[David T]

Hi guys, i removed my exhaust and have found the 2 thick cables and vac hose have been melted by the catalytic converter. I was going to open up the insulation and solder in new cables between the governor and transmission. Does anyone know how many wires run in each bundle ?
Thanks

If the conductors are not broken, strip off the burnt insulation and cover each wire with good electrical tape. If the conductors touched each other or the ground you may have blown the output transistors in the shift governor. Be sure to route the wiring harness well away from the exhaust.

[Andy_]

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From closer inspection it seems to be these 3 wires, not 2 wires and a vac hose.

72070

I can see the burnt insulation / wires going to the round plug. There are 3 wires on this ?bundle? of cables.
The other 2 sets seem to be harder to fix. I cant see the cables available separately from the module etc.

Does anyone know how many wires are in the other 2 ?bundles? (sorry cant think of a better word for them).

If this was your car how would you fix it?
Thanks david T, im going to investigate the wires more, i have had problems shifting between 2nd and third, trans would go 2,3,2,3,2,3 then stay in 3 until i slow down. So all 3 gears work, i cant be removing the trans this year, and assume it would have to come out to fix the diodes.
Any more advice greatly appreciated.

[David T]

72068

72069

From closer inspection it seems to be these 3 wires, not 2 wires and a vac hose.

72070

I can see the burnt insulation / wires going to the round plug. There are 3 wires on this ?bundle? of cables.
The other 2 sets seem to be harder to fix. I cant see the cables available separately from the module etc.

Does anyone know how many wires are in the other 2 ?bundles? (sorry cant think of a better word for them).

If this was your car how would you fix it?
Thanks david T, im going to investigate the wires more, i have had problems shifting between 2nd and third, trans would go 2,3,2,3,2,3 then stay in 3 until i slow down. So all 3 gears work, i cant be removing the trans this year, and assume it would have to come out to fix the diodes.
Any more advice greatly appreciated.

If you are getting erratic shifts, you most likely have to replace the large capacitors on the PCB (Printed Circuit Board) inside the shift governor. As bad as those cables look, they may actually be intact but in any case should be cleaned up and re-insulated with tape. The shift governor can be removed/repaired without removing the transmission. When doing the caps you also resolder/reflow all of the solder joints, on some boards there were cold solder joints that will also cause erratic shifts. If you do a search you will find plenty on repairing the shift governor, aka shift computer. You should also do a full On-Car service to the transmission and final drive. That includes changing the fluids, the trans filter, checking the line pressure, adjusting the linkage, checking the vacuum line to the pressure regulator, testing the kick-down switch etc. Refer to the Workshop Manual. if you need it, I can send you a full write-up about how to care for your automatic transmission.

[Andy_]

If you are getting erratic shifts, you most likely have to replace the large capacitors on the PCB (Printed Circuit Board) inside the shift governor. As bad as those cables look, they may actually be intact but in any case should be cleaned up and re-insulated with tape. The shift governor can be removed/repaired without removing the transmission. When doing the caps you also resolder/reflow all of the solder joints, on some boards there were cold solder joints that will also cause erratic shifts. If you do a search you will find plenty on repairing the shift governor, aka shift computer. You should also do a full On-Car service to the transmission and final drive. That includes changing the fluids, the trans filter, checking the line pressure, adjusting the linkage, checking the vacuum line to the pressure regulator, testing the kick-down switch etc. Refer to the Workshop Manual. if you need it, I can send you a full write-up about how to care for your automatic transmission.

Ok. I had another look, and managed to unbolt the cable ends from the firewall (next to the ballast resistor). 1 cable is fine, 2 are pretty toasty. There was then enough slack to pull the cables over the drivers side rear driveshaft with the wheel (and all exhaust apart from crossover pipe) removed. Ive removed some insulation and am pretty sure i can solder some replacement cables in (several wires are melted / stripped, and about half are now green copper and very brittle. But i have carefully separated each one from the melted plastic, and am pretty sure i can carefully solder in and repair each 1 at a time.

There is 1 ?bundle? of wires (the one with approx 10 thin wires in it) that had some shielding over it, a bit like tv antenna cable, and the shielding has melted over a 1 foot piece and all insulation for the wires is gone. Does this shielding need to be there? Is it a ground ? Or just for noise?

While i have the cables free i think it would probably be sensible to do the reflowing / capacitor replacement. Any info you can provide on this would be gratefully received.

[David T]

Ok. I had another look, and managed to unbolt the cable ends from the firewall (next to the ballast resistor). 1 cable is fine, 2 are pretty toasty. There was then enough slack to pull the cables over the drivers side rear driveshaft with the wheel (and all exhaust apart from crossover pipe) removed. Ive removed some insulation and am pretty sure i can solder some replacement cables in (several wires are melted / stripped, and about half are now green copper and very brittle. But i have carefully separated each one from the melted plastic, and am pretty sure i can carefully solder in and repair each 1 at a time.

There is 1 ?bundle? of wires (the one with approx 10 thin wires in it) that had some shielding over it, a bit like tv antenna cable, and the shielding has melted over a 1 foot piece and all insulation for the wires is gone. Does this shielding need to be there? Is it a ground ? Or just for noise?

While i have the cables free i think it would probably be sensible to do the reflowing / capacitor replacement. Any info you can provide on this would be gratefully received.

PM me your e-mail address.

[Andy_]

So while working under the rear i managed to smack my head on the razor sharp rectangular exhaust mount. Blood everywhere.
Managed to have another go today, soldered in some solenoid repair wires, but im not sure whats going on with the wiring for this (i assume speed sensor, looks like a modern abs sensor , mounted right by the cat.
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Theres definitely a wire shield wrapped around it, but inside its either a red and yellow cable, or 2 cables, 1 red, 1 yellow.
Is this a part available separately from the harness? I may be able to cut the cable back a bit more, and see, but theres not much left.
Ivelooked through the renault 2121 manual, cant find a wiring diagram of the harness.
Help please!


Ps for future reference the renault part number of the governor/computer is 77 01 585 496. Used in a renault 25 4141.

[Andy_]

Managed to get the full cable out, think i dodged a bullet, looks better than I thought.
72092

Gonna do a lot of splicing and soldering. Should work?

[David T]

Managed to get the full cable out, think i dodged a bullet, looks better than I thought.
72092

Gonna do a lot of splicing and soldering. Should work?

You can actually "bench test" it with an electric drill, a 12 volt source and a light box.