87bob

From a cold start the fans come on and stay on. Coolant sensor?

JimLentz

Is the A/C on? What temperature does the digital readout show?

pcolt94

Both fans should not come on from a cold start with the AC off. If the AC was on only the driver's side fan should come on. The passenger side fan is programmed to come on at about 239*.

If both fans are coming on at start, it may be in limp home mode. I would check the codes as there are probably some on module 4. This may give you a direction of what to look at.

But before I'd tear into anything, I would clear the codes but rather than using the dash buttons, I would disconnect the battery so the ECM does a full reset.

Start and drive the car again and see what the fans do and re-check for codes. Post codes if you want direction from the Forum.


I'm going on the assumption the car has been running normal and the problem occurred. And not a situation where you just got the car and someone did a botch job on the wiring.

sailor92a

my 90 had the same thing, code 15 replaced coolant sensor and works like a champ. no check engine light.

87bob

Great information!

87bob

I haven't be able to work on it but today I had to move it. With the key in the on position no fans. At start up momentary no fans then both fans kick in.