lost OD and TCC , trying to check TPS . followed procedure in teck tips . Got ref. voltage OK , got signal voltage at idol OK , no gain at WOT . Also checked according to Haynes , they say purple is pos. and black is neg. , when I put voltmeter on I have to switch pos. and neg. any glues , thanks

 

First of all, Welcome to this site. From your description, you must have a '96,'97, or'98. You need to fill in your signature. It will help for problems like this. My Haynes says that with the key on you should have 8.0 volts between the violet/white and the black/light blue wires. You should have the polarity correct from what my book says. Is it possible the leads on your meter are switched? That is about the only way you would have reversed polarity. You should also have a smooth current flow from idle position all the way to wide open. If you see a jump or drop there is a spot that might be dirty. If you are somewhat adventurous you can pull the TPS and on the back there is a line that makes a loop. You can use a Dremmel tool and cut the TPS open. Then you can get in there to really clean things out. Just make sure you don't loose any parts or pieces. If you don't feel that adventurous, pull it off and spray contact cleaner in all the places that you can. Good luck and let us know what happens.
Tom
P.S. Do a search for "TPS" and you should have a lot of reading material.

 

If you check the TPS when it is plugged in to the connector, and you have pinned the connectors for your voltmeter, you should be reading + on the orange/dark blue and - on the black/light blue wire terminals. If you do not read somewhere between .5 to 1.5 volts at closed and 3.5 to 4.5 open, the TPS is bad.

Try cleaning it with a spray electrical cleaner and see if it will start working. Most times they will clean up and work again after cleaning. They are sealed (sort of) so it takes a real good soaking and washing to get them cleaned out.

The purple/white should be the + feed, and the black/light blue the - side, with the TPS out of the connector. That should read 5 volts.

 

Thanks for the reply , have checked the polarity again and it's still backwards , could theTPS cause this

 

The TPS can't change the polarity. It takes a constant voltage in and puts out a variable voltage. If you follow what RCW said, you will be able to diagnose the problem. I was looking at the wrong section when I gave you advice. Have you tried putting the volt meter on the battery for a check? Did you get the propper voltages? Other than that, I wold suggest that you call one of the tranny shops listed in the links section.
Tom

 

checked again for polarity , it is opposite , with the pos prob on purple/white and the neg on the black blue ther is a neg reading . when I switch them it shows 5v. Is there any other switches or sensers in the line that could cause that , like maybe a bad trans temp , or VSS ps checked meter on battery and it reads correct

 

It's almost impossible to get a negative reading, if you do it means your truck has a positive ground. If it did you would have a lot more problems than just the tps. I would suspect your meter.

 

OK guys , mistery solved . Took cover off wires and found three FACTORY splices. The black and purple wires were switched because the colors on the plug are wrong . they must have gotten a bad batch . On the female plug are the letters ABC , the should be A=purple B=orange C=black , mine are oposite , thats why the wrong polarity . In order to use these plugs they had to switch the colors . Hope this saves someone else three days of aggravation

 

Follow-up Put on a new TPS and back to normal . While they were out did a resistance test . Old one showed nothing . New one showed 7 between A&B - 12 between A&C - and 12 between B&C . I have a pictue of the factory splices but I don't know how to post it .

 

Well, I sure are glad that you "figgured" it out. That would have drove me up a wall. Everything back to "normal"? If so, that is great.
Tom

 

Don't you hate it when that happens?

 

Where did you get your new tps at?? Thanks,,,Rick

 

Rick

Got the new TPS from NAPA for $160 , dealer wanted $240+ . Goodluck