check engine light

Discussion in 'Fox 5.0 Mustang Tech' started by 1991stanggt, Dec 8, 2003.

  1. My check engine light has been coming on comes on around 1500-1800 rpm, so basically all the time. I scanned my codes and it said that it was the throttle position sensor...does anybody know what this means??

    also my AC doesnt work and it said the air conditioner clutch wasnt working right which is waht the guy told me when i bought the car. are they hard to replace, or expensive, anybody kno anything

  2. What code were you getting? The TPS is about $50, so you want to test it with an analog volt meter to see if it is bad or out of adjustment. You backprobe the black and green wires going to it and move the throttle slowly through its range to see if the needle bounces at all. It should rise steadily from about .95v to about 5v.

    The TPS is on top of the throttle body (TB) and has three wires, the third is orange.

    The ac clutch is not hard to replace, prolly around $100 or more. You will prolly need an impact wrench and a puller to remove it. I had to have these things when I did mine. Post up the codes you got. Good luck .
  3. usually they are out of adjustment

    my check engine light flashes off and on alot due to the cold weather. in the summertime it does nothing at all. when i had my stock MAF it would flash alot all the time. later on i put my Pro M 75mm MAF on and the flashing went away
  4. The A/C clutch is about $100 new or you can buy a compressor from the junkyard with a working clutch for about $50. The puller is about $16 if you have to buy one, Autozone will rent you one for free.

    The clutch hub is usually what fails, the rubber shock damper shears off from the steel hub and plate. The hub comes off without much problem if you have the puller. You don’t have to do anything with the refrigerant (R12 or R134a), you can replace the clutch without draining and refilling the system.

    A few simple electrical tests are advised before popping out the wallet to buy a clutch assembly. With the engine running, use a test light connected to the 2 wires on the A/C clutch harness to make sure you have voltage when you turn the A/C on. If the system is low on refrigerant, the clutch will not engage (safety feature, keeps you from burning up the compressor due to no oil). There is an aluminum canister on the firewall with a large hose leading to the A/C compressor. There is a pressure switch on it with a 2 wire connector: pull the connector off and jumper the wires. The compressor circuit will power up, and the test light will light if the electrical circuit is good. This test is also a good way to check the compressor & clutch if the system is low on refrigerant. You can jumper the wires and the compressor will turn if the clutch is good.