Grand Cherokee Electric Fan

[BrokenXJ]

2000 Grand Cherokee - radiator fan will not come on.
I pulled the funky relay under the passenger head-light. Jumpered two thick wires and radiator fan came on. I turned the car on with a/c and used a test light on the two remaining connections. Nothing! Let car warm-up to about 220, and still no power on either of these relay connections that I thought would call for the fan to come on. Any help would be appreciated.

[jeepsrock]

A relay has 4 connectors on it mainly- Two cary high amperage current to the device this being a fan and the other two carry a low carrying control current that trips the fan. If you connect the two high amperage wires together you complete the circuit and the fan comes on.

I believe if you run the AC and test the other two the light should come one- tho i am not sure if the light will light with the relay in there.

pete

[BrokenXJ]

That is what I did. There is no power on either of the two non-current carrying wires. On my 88' cherokee, if you turn on the a/c this signals the auxilary fan to turn on.

What would make this happen?

[langer1]

2000 is different, the fan don't always run with the AC.

[BrokenXJ]

If that's true, where is the temperture sensor that drives the fan for the 2000 Grand?

[langer1]

The one in the thermostat housing does everything engine related, the duel pressure switch in the A/C controls it for the AC.

[jneary]

those relays go bad often. usually from high resistance from the fan. unfortunately, both should be replaced