91 Z 305

It was finally warm enough today to get a few minutes playing with the car. The other day I tested the wires by jumpering the big wires at the relay and the fan worked. Today I pulled it out started it let it warm up a little turned on any and all a/c defrost settings and the fan would not come one. So I stripped away a little wire casing on the green wire and then they DO come on. The 6" or so of exposed wire where it breaks out of the harness is in great condition. The connection to the relay is great.

Where else should I look?

Considering it doesn't come on with the A/C or defrost does that rule out the temp sensor as a cause narrowing it down to the wire or ECM since the fans are confirmed to work?

I forget where the ecm is in these. Haven't touched one in 10 years and 3 cars but could I use a multimeter and check a lead at the ECM to narrow it down to the ECM or Wire?

Please, Thanks LOL

 

Update: Apparently I didn't do enough homework and hadn't seen the ALDL jumper test. I did that now and the fan comes on.

So...

The relay works, the relay to fan wiring works, according to the jumper test the pre-relay wiring is good.

So is it the ECM or could it be something else too?