I am in the process of swapping engine/trans out of my '92 into another truck(gasser). The wiring harness in my truck is old and weather beaten, to the point where the wire coatings are coming of and wires are crossing causing a nice mess. My questions are, is there a way I can (and I only want to know this to keep the truck clean and simple) take the computer out of the truck? It seems to control the OD, but what else does it do? I have read about the POT trick for the OD but does this still require the use of the CPU? I want the absolute least amount of wires in this truck as possible. The '85 Crew Cab we did has close to no wires except for the essentials. Can this be done with my rats nest? Thanks.

 

The pot just replaces the TPS, you still need the PCM to run the OD.

What the PCM runs and how to "old school" it:
OD - look in the sticky for info on running that with an oil pressure switch.
Charging system - add an old style Chrysler regulator
WIF light - so what?
WTS light/intake heaters - momentary pushbutton
A/C compressor: a little rewiring on the factory relay
cruise control - brick on pedal

 

Hey thanks alot. I have enough old Mopars sitting in the barn for the regulator, A/C hasn't been charged in probably 10 years, and the C/C doesn't work. I guess it's a bit easier than I though. Thanks again, and any more helpful tips would be greatly appreciated.

 

Well, it's time. I have the truck ready for the engine and trans. I have a question about the O/D wiring. If I do the PSI switch O/D switch, will I still be able to delete the PCM? I don't want it in, near, or around my truck. I have pretty much everything laid out and ready to hack but don't want to without knowing about the O/D.

 

The pressure switch will run the OD just fine, to a point. It will kick into OD when governor pressure reaches the closing point of the switch. It is automatic, but it doesn't work exactly like a properly adjusted TPS/VSS/PCM setup. A pressure switch will kick the OD in at the same speed regardless of throttle position, and it will not give a WOT kickdown until road speed drops to the point that the valve body will drop you into 2nd. The TPS/VSS/PCM factory setup looks at road speed and throttle position and determines OD shift points based on those factors.

 

Thanks for the explanation. I want simplicity in my truck, so when I go on the road at any point I can fix it. Plus the wiring harness is beyond repair in this truck. I also plan on swapping out the fusible links to fuses.

 

I designed and wired a relay and a pressure switch to control the lock-up TC I'm putting in my truck. The same think can be wired for the OD...
A DPDT switch give me the option of always on or automatic on..

I can post the diagram if anyone is interested.

 

Not sure what you mean, but yeah post the diagram and maybe I'll get it.

 

Well, I hope you can see this well enough to understand it...
It's really simple :
There is a 3 position switch center is OFF TC cannot lockup
Throw switch one way the lockup works normal, throw it the other way it locks immediately.
2 leds show what's happening :
Grn led = normal operation - normally off, when pressure switch activates -led lights showing lockup.
Red led = manual operation - and the grn led lights to signal lockup.