Radiator fan will not come on - AC works, ECTS good, Fan motor works

[billr]

I suspect slipping that hair-pin in from the mating side of the connector has disrupted the contact of pin/socket. Pierce the insulation of the wire going to the spare motor with a needle and read voltage at the motor wire.

[afskwarek]

Alright. I did that, got a solid contact from the wire with the connector plugged in. No voltage. Also, while doing the test I put the ac motor on the ac compressor for a second, there was a spark and the fan motor turned on for some reason. Don't know why. Took some readings on the connector as well with it unplugged. Twice got a good 14v, and one reading I got .5-1.5v.

[billr]

Jumper #30 and 87 at the relay socket. Still no voltage at the fan-motor end of the 87 wire? Check to see if #30 still has ~12V with the fan motor connected. If #30 still has 12V, and the other end of the 87 wire does not, then either the 87 wire is bad or its connection to the underside of the 87 relay socket is bad. I have mentioned that before, you should check that connection on the underside of the fuse/relay panel.

[billr]

PS: I see that somehow I got "off in the weeds" talking about the A/C compressor. The is no problem with the A/C, correct? Any mention I made of "compressor" should probably be for the fan motor...

[afskwarek]

No worries. I assumed you meant fan not ac, and yeah ac is fine. So I jumpered #30 and #87. No voltage at the fan connector wire while plugged in with ac on. Removed the jumper, turned on ac and tested voltage at pin #30 and yes, it has good voltage. Guess it's time to look under the fuse/relay box.

[billr]

You have to check for voltage at #30 with the 30-87 jumper in place and the harness connected to the fan; there has to be a load on the circuit, drawing current, to be sure the 12V at #30 is really OK.

[fetchitfido]

Pin 30 is power from the battery, through one of the giant green 30a fuse's. This should have power 100% of the time (not just key on) so if it doesn't the first thing to check is the fuse. Pin 87 is a direct line to the fan connector. If the fan runs when you jump pin 30->87, I'm unclear why this side of the circuit is still being tested as it's time to move to the relay control side of the circuit (pins 85 and 86).

[billr]

One of us is confused here. My understanding is that the fan does not run when 30 is jumpered to 87, and there no/low voltage at the fan-end of the 87 wire with 30-87 jumpered. Hence, we are ignoring the relay and its drive circuit.

[afskwarek]

Okay, so I did test for voltage with 30 and 87 jumped. Got nothing.

Anyways, I'm 99% sure it's a ground wire issue. Followed the troubleshooting flowchart. Got to the "With an ohm meter check for an open in black (650)" bubble. Since I'm not entirely sure what setting to use to perform that test, I attached another fan connector with a couple feet of wire (what I used to test the fan motor) to the actual connector on the car with the black wire touching the body with vice grips and blue pushed into the corresponding port on the connector. When I turn on the AC, the fan motor comes on. When I turn off the AC, the fan motor turns off.

https://ibb.co/smmNyf4

[billr]

"I tested the fan motor via a direct 12v connection to battery. It comes on and works fine."

Remember that from your original post? The ground would have to be OK for that to be true. I'm confused...

Also confused as to whether #30 still has 12V with the 30-87 jumper in place and the harness connected to the fan.

[afskwarek]

The fan motor was tested with a separate fan motor connector and few feet of wiring cut off from a scrap yard car with wire ends placed on the battery terminals. Also yes, I tested with the jumper in place with fan connector plugged in and and the funny thing is after I wrote my last post I tested it again and got around 2v when the previous test was 0-0.3v. Either way, way less than 12v.

[billr]

"...got around 2v when the previous test was 0-0.3v. Either way, way less than 12v."

That voltage was at #30? If so, it seems that the feed to #30 is bad. Still, probably a bad connection on the underside of the panel.

With the harness connected to the fan, connect a wire from the battery + to #87 (30-87 jumper removed), see if that turns the fan on.