oldcancer
NAXJA Forum User
- Location
- Edmonton, Alberta, Canada
why has this not been stickied yet?
oh well this one is frayed so ill order a new one and change it out and see if that helps. But i'll still need that diagram if you still have it. Thanks for your help.
Overriding and supplying power to solenoid 2 will keep you in 2nd, yes. Bear in mind that I'm not sure what effect, if any, there could be on the TCU once it starts seeing the opposite bias voltage on the pin it uses to send + voltage to the transmission shift solenoid. A simple diode may be all that is necessary to ensure no damage to the TCU takes place.
I don't believe you'll have an issue just pulling it to 12V but I'd suggest not doing it anyways just to be on the safe side. It's as simple as using an SPDT switch instead of an SPST - cut the wire for solenoid 2, wire the solenoid to the COM terminal, the TCU to one of the others (choose it so that the switch position is where you want it) and the other terminal to ignition switched 12V. If you also want a first gear override to hold first, use an on-off-on SPDT, one of the ON positions will be factory behavior, the other will be forced second gear, the off position will be forced first gear.
For an 87-97, put a 12v test light on the pin at the TCU for the speed sensor, then with the transfer case in neutral, put the transmission in 1-2 and let the engine idle. You should see the test light flicker a bit - if not, put the transmission in neutral as well, the output shaft will spin slowly and you should see the test light blink regularly. Shut the engine off before putting it back in park.
Thanks for the reply-I didn't see it until today. I hooked up a meter to C3 on the TCU and watched when I drove. I could see the off/on at low speeds and then of course it got to fast for the meter. Once it warmed up, the voltage became constant and it wouldn't shift out of first again. I went underneath and moved the wires around and it seemed fine for a couple of days. Now I get no voltage change at all and of course it's in first. I put a switch on the TCU and if I turn the power off, I can drive it by shifting manually. Do the speed sensors go? I don't mind swapping a new one in but I'm wondering if it could still be an electrical short somewhere. It's really dirty in there. Do you have a close up picture of where the speed sensor is? I saw on one of your earlier posts a picture of a 95 I think. I'm trying to figure out what harness does what.
Thanks for the great info!!