Electric Fans - Low speed not working...
 

With my PFC everything works fine, with the stock ECU I don't have all of the fan speeds. Maybe I just dont have the low speed and the PFC just activates the other working relays... or I might be mistaken here... PFC I have dialed in to turn on the fans at 195f, where as with the stock ECU nothing came on at 220f so I turned on the parking lights and the fans came on... With the FC thermoswitch my understanding is the low speed should kick in at 205f...

I have removed the recall box as well as the pig tail out of the relays in the engine bay. (they were all corroded and falling apart, yes I know it was put there for a reason but I need the stock ecu for smog.)

I have put an FC thermoswitch in place of the FD one as per recommendations reading/ Dale Clark's find etc.

I have tested all 3 relays, all are working fine. (tested via Service Manual instructions.) (4th AC relay works fine too.) I think I have found the problem but I don't have another FD to check with. (sad I know... ;)

Should all 3 relays have power to them with the key in the ON position? I know they need to be activated via different conditions, but the larger wires. Two of them have 12v to them. If you connect them the fans activate. The 3rd one however has NO power to it, so I think this might be my issue.

Edit: Attached pictures. 1. No Power,2. Power, 3. Power, 4 No Power. If someone could check and see if they have 12v to their Blue with orange stripe wire. Or the black wire... that would be great... ;)

Thanks for the help,
-Brian

The blue/orange is ground from the fans and the black is a ground wire. Try grounding the wire at the thermoswitch, if the fans come on the switch may be bad. If they don't, ground the Blue/Green at the same relay connector. If the fans come on, there is a wiring issue between the switch and the relay.

Paul