Formula413

iTrader: (1)

I recently wired up a manual fan switch for my car using the Shoebox diagram. It worked fine for a while but now I can't get the high speed setting to work. It just runs on low speed no matter which way I switch it. However, if I open up the fuse box under the hood and wiggle one of the fan relays while the switch is on, they come right on. The contacts on the relays look clean and tight. Anyone have any idea what might cuase this?