Keep blowing high speed fan relay

[GNRick]

I got home from a 30 mile trip and temp was over 200. Popped the hood and saw the dual Spal fans were not running. I turned on the A/C and then they ran, temp came down to 180. I replaced the high speed fan relay with one from my other car and fans came on for 5 sec. and then shut off. I put the relay back on my other car with a stock fan and now that fan only runs on low. So it looks like I blew two high speed relays. Anybody know what could cause this? Last week end we replaced the timing cover and I'm thinking maybe the intercooler hose is touching the fan motor. Could this cause arking or something? Thanks.

 

[Benched]

I got home from a 30 mile trip and temp was over 200. Popped the hood and saw the dual Spal fans were not running. I turned on the A/C and then they ran, temp came down to 180. I replaced the high speed fan relay with one from my other car and fans came on for 5 sec. and then shut off. I put the relay back on my other car with a stock fan and now that fan only runs on low. So it looks like I blew two high speed relays. Anybody know what could cause this? Last week end we replaced the timing cover and I'm thinking maybe the intercooler hose is touching the fan motor. Could this cause arking or something? Thanks.

Check to see how many amps the fans are drawing. It could be too much for that relay.

 

[Red C5]

Was everything ok before the timing cover replacement?

 

[GNRick]

Check to see how many amps the fans are drawing. It could be too much for that relay.

So I would do a hotwire directly to the fans from the battery and touch the wires with my voltmeter?

Was everything ok before the timing cover replacement?

Yes.

 

[Nick Micale]

When we use dual fans, we also use a new 30 amp relay for each fan, not the stock 25 year old fan relays.

Usually, only one fan is needed for cooling in normal weather, so we have one fan turn on with the computer, the other with a manual switch.

It is also important to run the power AND ground leads for the fans DIRECTLY to the battery. In-adaquate voltage will quickly kill a relay or fan motor.

 

[GNRick]

Nick- I installed these Spal fans 2 years ago. Probably have 7-10k miles on them with no issues. I also have a front mount intercooler so I think I need both fans on all the time (plus I'm sure I would forget to look at the temp gauge and put the second fan on). Do you think I need Caspers fan delay or is there something else I'm missing? Also, the fans don't come on "low". When the fans were not running, the low relay was still connected. They only came on when I replaced the high relay or turned on the A/C. I'm using a Racetronix plug and play harness. I have all fan wires twisted together (positive wires together and neg. wires together) and then connected to the fan harness. Can I just go to the parts store and ask for a 30 AMP relay, or is there something else I would need to know? Thanks.

 

[GNRick]

I feel smarter now. Explanation of how a relay works: http://www.mp3car.com/the-faq-emporium/117895-faq-relays-how-they-work-and-how-to-wire-it-up.html

 

[Racetronix]

Nick- I installed these Spal fans 2 years ago. Probably have 7-10k miles on them with no issues. I also have a front mount intercooler so I think I need both fans on all the time (plus I'm sure I would forget to look at the temp gauge and put the second fan on). Do you think I need Caspers fan delay or is there something else I'm missing? Also, the fans don't come on "low". When the fans were not running, the low relay was still connected. They only came on when I replaced the high relay or turned on the A/C. I'm using a Racetronix plug and play harness. I have all fan wires twisted together (positive wires together and neg. wires together) and then connected to the fan harness. Can I just go to the parts store and ask for a 30 AMP relay, or is there something else I would need to know? Thanks.

Did you check for answers / ask for help on our tech support forum?

 

[GNRick]

Did you check for answers / ask for help on our tech support forum?

Hey Jack. I bought a 5 pin 30 amp relay and all is good, at least for now. Turns out I had rewired the fans so that one fan comes on when low speed is called for, and both come on when high speed is called for. Spent the weekend replacing the return (driver side) fuel line, fuel filter, and installing a Red's fuel pump and new hanger. I left the fuel line at the back of the car that connects to the fuel filter, and also the line that comes off of the fuel pressure regulater. I had a friend helping me. Didn't lift the body off the frame, just broke the line and wrestled it out.