Radi

Yes, but you'll have to shift 1-2 - 3 by hand and won't have the torque converter lockup.

67 GMC

So, no overdrive then. Is it harmful to the trans? With the issues I've been having, I'm worried I'll be on the highway and it will act up and red line. If the TCU is disconnected, the gas mileage will suffer but at least it will be driveable.

Thanks for the reply.

Radi

The trans will also run a bit warmer without the converter lockup so take it easy..

67 GMC

I think I've hijacked this thread now but the OP sounds like he's happily driving his Jeep which is more than I can say! Haven't put the new TPS in yet as the intermittent shifts fine/doesn't shift at all makes me think of electrical grounds or shorts. This was tucked up under the dash below the glove box. When I got the Jeep, there was a burned and corroded fuse which I replaced with the crimp on connectors. This loop of wire on its own connnector has me stumped. It has infinite resistance (open) and there is 12 V to it. I'm not sure if it was a fusible link that was bad. I'm tempted to just jumper it to see what happens but I thought I would send the pic just in case it's something else.

cruiser54

Do you know that the shift logic ground circuit is at the engine dipstick tube stud?
Have you ever given this Jeep a complete ground refreshing?

67 GMC

I did the dipstick grounds over and cleaned the C101. There's some aftermarket remote car starter installed that I don't have the remote for so another project will be to remove that stuff to avoid more electrical issues.

DFlintstone

I'm pretty sure what you found there is a resistor..200 Ohm? IIRC. I'm not sure. I guess if mine was truly "Open", I'd be looking at the JY for another.

If your 10A fuse and that are toast I'd take a good look at the wiring. No idea if a shift solenoid could do that, maybe.

Radi

yup. That's where the resistor pack goes. It's 1.2 ohms.

cruiser54

What happens if you eliminate it? I thought I read somewhere that it worked fine without the resistor, just jumped.

Radi

It's there to limit current draw in the brake switch/TCC lockup circuit in the event of a fault condition, probably would run fine jumpered.
If there were ever a fault in that circuit, the TCU could be damaged without the resistor to sacrifice itself first. The resistor is supposed to limit current draw until the fuse blows.

cruiser54

Good to know. Maybe we should be snagging those resistors at the JY?

67 GMC

Could someone check their resistor pack for me? Mine is reading about 1200 ohms, not 1.2 ohms. The part number is 83504880 but the description reads 1.2 ohm resistor pack. 1.2Kohms would be 1200.

I cleaned up a lot of wiring yesterday. Separated the fuel injector and sensor wiring and re-ran them through new conduits. There was a ground wire in there that connected to the end of a stud at the rear of the engine near the main braided ground strap. I shined that up as well. The resistance between the sensor ground and the negative battery dropped from 2 ohms to 0.8 ohms so I think that made things better. The trans seems to be shifting ok today but now the engine is stalling a few times at idle which didn't happen before I cleaned up the wiring. I had adjusted the TPS to get the right readings. TPS may be flakey so will replace it once the new one gets here.

Thanks

cruiser54

Replace the TPS and adjust it now that you have a good ground for it.

67 GMC

Will do. Thanks for your help and your invaluable write-ups.

cruiser54

You're welcome. Keep us posted and enjoy your Jeep.