My car overheated to the point of spewing coolant .I noticed the cooling fan not coming on with temp or the OBD port jumpered. Also the A/C fan isn't coming on when I turn the air conditioner on either. Are these both on the same relay? All my fuses were good. I'm stuck on the road right now or else I'd be into the book at home.
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See if you can find another relay with the same part number on top of the relay and swap them to see if the relay failed. I can't answer your question about having 1 or 2 relays controlling the fans. Sorry.

 

 

So if I understand the diagram properly, if the block fan switch failed, the one in the head should have turned on the AC fan at the higher temp. It did not. Has to be the main feed wire as that's common to both.

 

no,....

The ECM controls 1 of the fans,..... the switch in the pass side head controls the other; each fan has it's own relay. ( there is no block mounted sensor. )

The same ORANGE wire (full time power ) leads to both relays,...... the same BROWN wire ( Ignition power ) also leads to both relays. Check ORANGE for hot at all times, check BROWN for power when key is turned and verify ground at both relays and @ each fan.

P.S. The switch in the drivers side head is for the temp gauge.

 

Solved it. It was a tricky one. Troubleshooting this was deceiving. I had 12 volts on both orange wires. When jumped directly to the black/red fan wire they did not turn on. I suspected a current issue so I went directly from the battery to the black/red and they worked. A multi-meter will show 12 volts, this is where the deception is. I had the volts just not the current. Did some tracing and found the connection at the battery to the fused link was badly corroded, and hanging on by a few strands of wire. After wiggling it there was intermittent fan operation, then the connection disintegrated all together. This is the 10 gauge wire that comes off the positive terminal, about 4" long. If it weren't for the fact that both fans were out, one could easily fault the fan motor with this issue. I just figured the odds of losing two fans at the same time is slim. And the 2nd fan never came on, and they only had the one thing in common. Power. So take corrosion into account. Most flow charts and fault isolation in a 30 year old manual doesn't really factor corroded wiring.