Okay, I have checked all the circuits that showed resistance from the computer connector.

#1 - 1.8 ohms - KA PWR - shows open when I unplug #9 fuse from under the hood.

#2 - .9 ohms - BOO - does not change when I unplug the connector on the brake pedal (I am not sure if this is the right connector, but it is the only electrical connector on the brake pedal...?)

#6 - .2 ohms - VSS (-) - No change when unplugged from the rear end

#8 - 2.5 ohms - FPM - shows 2.5 ohms when fuel selector is on front tank. Shows open when I trip the inertia switch. Goes to 59.8 ohms when I switch to rear tank.

#10 - 30.7 ohms - A/C ON - shows open when I unplug the connector on the compressor

#12 - 23 ohms - 4 LOW INPUT - does not change when I unplug the only connector I can see on the transfer case. Also does not change when I pull fues #12 and #18 from inside the cab.

#16 - .1 ohms - IGN GND - shows open when I disconnect the distributor plug

#43 - 4.3 ohms - A/C DEMAND - shows open when I disconnect the distributor plug

I have not looked over one, that is all the pins that showed any kind of resistance on the computer connector except #20, #40, #60 because they are all ground wires.

Any thoughts? The BOO switch is making me wonder. My air conditioner only blows hot air now and the compressor kicks on and off every second or two. It started leaking freon when I changed engines two years ago and had to put a couple of cans in last year, so I don't know is it is because it is low on freon or something is electrically wrong.

 

I take it you mean fuse "I" if so this is normal with it unplugged but if the battery is not disconnected it should be battery voltage with the fuse in.

This normal, you are unplugging and open switch and the circuit also goes through light bulbs to ground.This is a ground wire so this is normal.

2.5 ohms is normal & open is normal with tripping of the inertia switch.
The circuit to the back pump has a problem or the rear pump is bad.

I take it the battery is unhooked so this is normal.

This wire goes to a bulb and IC boards so I would think this also normal.

Normal, the distributor is the ground for the ignition system.

If you meant to say compressor plug than this normal. Has nothing to do with the distributor.

Low on freon.

 

Thanks a lot for your time.

1. I don't have any fuses labeled "I" or any other letter for that matter. The fuses under the hood on the driver's inner fender well and in the fuse block inside the cab are all numbered. It is labeled as "I" in the wiring diagram I have so I think we are talking about the same fuse.

2. I did pull the bulb for the third brake light but I guess it is still going through all the other lamps as well.

3. The rear fuel pump is louder than the front and I have been running on the front pump for several months now.

4. The battery has been disconnected all day during these tests.

5. I did mean to say compressor plug.

6. Looks like I need a little more R12.

Well the bad news looks as if I still have not found a problem. I was hoping to find something along the way that may have caused two tps switches to go bad and the computer to fry.

 

As I recall reading somewhere the shift sensor on the side of the transmission was defective and there was an up graded replacement for it. It would send different gear selections to the computer as you drive and the transmission would shift to the wrong gear as you drove. The seal was bad on it and water would get in and short it out.
I am not sure if there was a recall on it or not.
There was a big thread about this at one time over in the Transmission Forum. I will try to see if I can find it.

 

I would chang out the MLPS sensor (or may be called TR sensor)and if that does not smooth out your transmission then I would change the PSOM.

 

Well, I have installed the tps and set the voltage to about .994 at closed position. I have put everything back together and I have going to put my code scanner on it and go from there.

Wish me luck!

 

Okay, I got a 111 then a 111 then a 1 then a 512 then a 512. So far so good (I think).

 

Sounds good so far, the 512 is normal when first hooking up the Computer or unhooking the battery, clear it and try again.

 

Okay again, all I did was start it up without ever touching the throttle and let it idle for just a few minutes. Then I went ahead and ran the code scanner and came up with the following: 116 (ECT signal voltage higher or lower than expected), 311 (thermactor problem; no operation during self test- I have removed the operation of the thermactors), 332 (insuffiecient egr flow- I have the egr eliminator), 538 (insufficient rpm change - ?), 536 (BOO switch not activated - I did not do it), 632 (overdrive cancel switch - I did not do it either).

I still have it idling and I am going to run the test again after it is warmed up.

 

You may still have a bad MLPS sensor that could short and take out the computer.

 

Yes, that is what I am afraid of.

I warmed it up this time and did the BOO and overdrive switch. This is what I got: 311, 332, and 538.

Everything has worked out good so far but I have not drove it yet.

Is there a way to test the MLPS? I guess they changed it out two years ago when I had the tranny rebuilt but I don't know for sure.

 

I would have think about the testing but I can tell you that their is a TSB out on it for a new design. The TSB is 95619 and this is just for the A/T E4OD.

 

Well I have drove it for 5 or 6 miles without any problems...yet. Everything just runs perfect. The idle, power, tranny shifting are all perfect. I find it hard to believe it would be the computer. If it was not the right one, it should never run right.

Anyway, I am going to go a little further this time (with all my tools and a cell phone!)

 

Well I have drove it for about 20 to 25 miles without any problems...knock on wood! I will still have to drive for a few hundred miles before I feel comfortable with it. I hope it is fixed for good.

I want to personally thank everyone for their help. I simply could not have had the success I have had in dealing with this problem without this site and the people involved.

Will Muncy.

 

Glad you got it fixed! Thanks for sticking with the problem and doing all the troubleshooting. Most folks just want to throw parts at it, but you sat down and did the work, and so far all it has cost is a new TPS. Hope this fixes it for good.