Both fans turning off and on at same time

[Tzar177]

I installed a perma-cool and mishimoto radiator fans along with a 170 gates thermostat a few months ago. A problem has popped up recently(or at least just noticing) where when I have either the heat or AC on that both fans will kick on at same time for about 10 seconds, then both shut off together for about 10 seconds then they both kick back on. On and off, on and off. That just continues until I turn off the heat or AC. My volt gauge is going haywire during this time. Anyone have some insight as to why both fans are only working together? No, they are not wired together

 

[Spiced MSP]

One fan is your AC fan and the other is your radiator fan. Both do turn on when you turn the AC on. Mine did it too before swapping to a half size radiator. Even with one fan, it turns on with the AC.

 

[Tzar177]

Yea i know what the fans are for, they just never turned off and on so much before

 

[dacquesta1]

sounds like it could be a faulty relay

 

[Tzar177]

sounds like it could be a faulty relay

Which relay?

 

[dacquesta1]

there are two relays one for each fan. i was taking a stab...electrical i am not very good with. my guess would be one of those relays.