I am having troubles with my tps and I want to test the tps before buying a new one. My question is what is each wire suppose to read. I understand the red wire in the middle is supposed to read .5 volts closed throttle and 4.5 volts wide open. What are the other two wires suppose to read? what are the other two wires for? Thanks.
Google for tps test, but I think the way to test it is with the harness disconnected and you check resistance. IIRC, you check the middle one against each of the others, and make sure that resistance changes consistently as the TPS is moved through its range. I know it was for my 1987 Cadillac HT4100 TBI.
You should get a circuit diagram. A TPS is usually a 3 terminal variable resistor aka potentiometer. Between one of the pairs which is usually the two edge connectors the voltage or resistance will always be a constant. Between the remaining two pairs the voltage or resistance will vary when you turn it. One pair will start low and go high and the other will start high and go low. If the TPS is unhooked you measure resistance. If the TPS is hooked up and the key is on you measure DC voltage.
Find the pair that varies from about 1 volt to 5 volts and that's your test points.
OKay so I tested the three wires, and I hope I can get some response from someone. The left wire I got 0v The middle wire was .5-4.5v and the right wire was 5v. Can some one confirm this? Is there any downloadable wiring diagrams or anything wire associated on the web?