TPS voltages *WAY* off ?!?

[jb89coupe]

Just changed my throttle body today and went to install/adjust the TPS.
I've read two ways to get a reading. The first is to probe the green TPS wire + and the black TPS wire -. The second is with the green TPS wire + and battery ground -. And from what I've read, I should get a reading of ~ .9vDC?
Well, if I do it the first way, I get about .003v koeo. I drilled out the screw holes and was able to adjust it to .009vDC.
If I try the second way, I get about 4.5vDC. If I slide it around it moves in .00x vDC incriments.
What gives?? None of these numbers are even remotely close to what I've read they should be. I've tried this with 3 different TP sensors and have had the same results w/ all. And yes, I'm sure I'm using my meter correctly, and it's properly calibrated.

Any advice would be appreciated.

 

[jrichker]

With power off measure the resistance between the black/white wire and the battery negative post. You should see less than 1 ohm. More than that means bad wiring or a bad connection.

Check the same black/white wire on the EGR and MAP sensor. More than 1 ohm there and the wire is probably broken in the harness between the engine and the computer. The 10 pin connectors pass the black/white wire back to the computer, and can cause problems.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

 

[jb89coupe]

Alright. That diagram helped a lot. I think the problem is my computer; the resistance tests checked out ok. My CEL is on constantly, and I have a code present for every sensor or pin 46 in the diagram (ect, tp, act, bap, evp, nds) - most have been replaced or tested and the codes don't go away. I've been having problems with pinging, bad idle (sporatic), and power loss, and now the tps.
A while ago I swapped computers with a friend - my car ran fine with no codes present using his eec, and his car had the same problems I did using my eec (same codes, CEL on constantly).
So I think I can rule out a wiring issue. I'll just buy another one and cross my fingers that the pinging goes away too.

Anyone in the market for a broken a9l?