I have a single fan setup on a 91 TBI. I replaced the motor but the fan still doesn't come on at all. Is it the relay? If so, where is it located so I can troubleshoot?

Turn the key to the run position
unplug the fan switch pigtail from he head, between cylinders6 and 8. Ground the pin in the center of the plug to the block and see if the fan turns on.

If it does, the switch is bad, if it doesn't, the relay is possibly bad.

Fna relay in on the firewall by the brake booster.

Which ones are 6 and 8 and what does the pigtail look like?

Does anyone know what pins to jumper out to test the relay?

6-8 are the back two on the passenger side of the motor

There are a few relays that look the same, can any specify which one it is?

I grounded the switch and it still doesn't kick on. I also tried reseting the ECM. I think the only thing left would be the relay, besides if it was the switch wouldn't it still work with the A/C on? It seems like the relay is what's common in both. I just don't know which relay it is. There are 3 that look the same. Two in the driver's side. One on the pass. side. Does anyone know which one it is?