Resolved Cooling fans won't turn on (fixed, blew the fuse)

[ErikTande]

The coating on the wires on one of my slim fans dry rotted away and shorted the fan out, now the fans don't work at all.

I replaced the fans and they both work when 12v is applied directly.

When wired into the factory harness (Passenger side) to the blue and black wires, they do not work.

When I jump the radiator thermo switch connector (little white connector) with a wire, I hear the fan relays click. But the fans don't turn on.

I swapped the fan relay with the fog light relay, on the passenger side fuse box. The fog lights still work but fans still don't work. So the relay should be fine.

I also used wire to jump the relay in the passenger side fuse box for the fans, which causes the drivers side relay by the firewall to click, but still no power to the fans.

Any ideas?

 

[boostdawd]

U may have to trace the fan wires all the way back to the fuse box. If u don't want to go through that hassle then rewire them on a seperate relay and have the ground activate them like factory or use a toggle switch.

 

[lasershark]

You could trigger the fans via ecmlink then test for power at the fuse and test for ground continuity as well. Gotta be either or if the relay is still triggering via thermo switch.

 

[livedsm4g63]

Try jumping the relay? Just because it clicks doesnt mean its making contact.

 

[greddy_1700]

Sounds like your fan wiring for sure. I had an issue on my 91 where my fans wouldnt turn on, but every part of the system tested good. Turned out that my factory wiring connector for the fans (bottom passenger corner of the rad) had failed and wasnt making proper contact anymore. I simply cut this connector out since I had put a new connector to splice in the fan wiring. It has worked perfectly since.

 

[gsxeclipse102]

Did you check the fuse? Sounds like the fan fuse blew. If you jump the thermoswitch you should have power and ground at the fan.

 

[ErikTande]

You could trigger the fans via ecmlink then test for power at the fuse and test for ground continuity as well. Gotta be either or if the relay is still triggering via thermo switch.

You can't trigger the fans with ECMLink on a 1g ECU. Not that I'm aware of anyway. I'll test for power at the fuse though, I haven't done that yet.

Try jumping the relay? Just because it clicks doesnt mean its making contact.

I swapped the fog light relay and fan relay, and the fog lights still work. Wouldn't that rule out the relay?

Did you check the fuse? Sounds like the fan fuse blew. If you jump the thermoswitch you should have power and ground at the fan.

Yep, all the fuses look good. I'll test for power at the fuse though, I haven't done that yet.

Sounds like your fan wiring for sure. I had an issue on my 91 where my fans wouldnt turn on, but every part of the system tested good. Turned out that my factory wiring connector for the fans (bottom passenger corner of the rad) had failed and wasnt making proper contact anymore. I simply cut this connector out since I had put a new connector to splice in the fan wiring. It has worked perfectly since.

That's a good idea. The connector on the fan side works (I tested it) but I'm not sure of the connector on the car side. I'll check that next.

 

[19gsx91]

@luv2rallye

I can't offer any good advice, but maybe ^^ He'll have an idea. good luck Erik!

 

[lasershark]

You can't trigger the fans with ECMLink on a 1g ECU

Did not know that, only played with 2g ecnlink thus far... good to know.

 

[livedsm4g63]

I swapped the fog light relay and fan relay, and the fog lights still work. Wouldn't that rule out the relay?

Depends if they are single/double and pull/throws. That I cannot say, as I do not know without looking.

 

[gsxeclipse102]

The fuse is on the battery post I believe. Easiest thing to do is jump the connector for the radiator fan switch. Then check for power at the fan

 

[ErikTande]

The fuse is on the battery post I believe. Easiest thing to do is jump the connector for the radiator fan switch. Then check for power at the fan

Oh, I didn't check there. I'll double check that as well when I get home. I have the JMF small battery relocation kit so that connector is tucked way down, didn't even thinkg about it. Thanks!

 

[ErikTande]

The fuse is on the battery post I believe. Easiest thing to do is jump the connector for the radiator fan switch. Then check for power at the fan

Checked the fuse on the battery post, it was blown. Fixed, thanks!

 

[boostdawd]

Nice man! Glad u got it all figured out!

 

[lasershark]

Always nice when it's a simple fix

 

[gsxeclipse102]

Glad I was able to help.