Hey all, So my electric fan dosn' t work, I stuck a voltometer in the hasness that hooks up directly to the fan. There is no power getting to the harness, thus no fan. I have no idea what the fan relay looks like so im asking the pros. Can the fan run without a relay? And what does it look like? Pictures would help a fellow 3G wonderfully.

 

hey there it one of the 3 lil boxes closes to the driver side firewall !
yes you fan can run manually with a hard wire and a toggle switch !
ill look up some pics for ya !






i had a manual toggle switch on my car iam in the process of re doing my cooling system ! good luck !

 

Running without a relay will burn up whatever switch you have on there very quickly. Fans pull 20-25A

Later TBI cars used a thermo fan switch in the pass cyl head to automate relay control independent of the ECM. These switches have a short life span

Test it and see if the circuit still functions, unplug the switch and shove a wire inside it and ground that. With the IGN on, the fan should engage. If it does not, then the problem is upstream. Check the fan fuse. The fuse is shared with the alt, so if you're charging, the fuse is ok. Next move to the relay itself, remove it and bridge the two large wires. If the fan engages, the relay is dead. If the fan does not engage then the fusible link is blown or the fan motor is dead

 

I hate to be that guy but could you please tell me which one it is lol I have yet to see my fan turn on other than when using the diagnostics key, i have little experience with this stuff so im just replacing what i can to hopefully solve the issue. Any help is very much appreciated.

91 firebird 3.1 TPI

 

Look at the wiring attached to them.

The one whose plug has a big fat red (batt), big fat black w/ red stripe (fan motor), thin green w/white stripe (temp switch) and thin pink w/ blk stripe (ignition power) is the fan relay.

If the fan comes on in diagnostics mode then the relay is fine. Leave it alone and find the true problem.

3.1 is a 6-cyl. It is not TPI. TPI was a FI system specific to V8s, it did not come on 6-cyls.