then when they reach temp, they turn on loud and cool the motor down then go back to low speed, What is it, the water pump temp switch bad??? No check engine light or codes.

Eric

 

Maybe you have a ground on one of the relay leads or you have a stuck relay. Try swapping relays around.

It would help to know what year car and how many fan relays you have.

 

dual fans, so I assume two relays, but both fans turn at low spped???

 

A 1995 will have 3 relays. Both fans are supposed to run at low speed on initial engagement.

 

started car and both fans were off then they both came on at LOW speed and then as it got a little hotter it came on LOUD and cycled to back to LOW speed.

 

explain? I thought they were off and then come on, turn off.

 

 

If there is nothing wrong with the fan circuits, it might be the temp sensor in the water pump.

Here is a schematic for the fans. Use the lower one that has the three relays.

Here is info on testing the sensor.

It would be nice if you had a scan tool to tell you what the pcm is reading as engine temp. That would tell you if the temp sensor was a problem.

 

by pcmforless.com, Brian is not sure either.

 

I had one of these switches bad on a Turbo Trans Am and it would show good when the test was done but I got a new one and it was the culprit.

 

to run on low? As I said they are off when I start it, let it idle for a while and they come on low speed? Then it cycles on and off on HI speed, but the low speed always stays there??

 

the fan turns on, but low, then as it gets to the second mark on the factory guage it turns on high speed, cools down, turns back to low speed???

 

Any custom programming in the pcm?

You need to monitor it with a scan tool to see what the pcm is seeing.

Stock, the pcm will command low speed fans "ON" at 226º and "OFF" at 221º and high speed fans "ON" at 235º and "OFF" at 230º.

 

Has a 160 thermo and been programmed by pcmforless for the 160 thermo.

 

then it sounds perfect, when cold all fans are off then the low speed comes on, and when it gets hotttt the high speed come on and go off, but the low speed stays on, once winter gets here then the low speed will cycle too it sounds like.