The other day I upgraded my anemic 16″ pusher fan for a smaller fan that pushed out twice as much air. Sadly, it’s amp rating went from 15 ish to 25 amps. I wired in the new fan in place of the old one and started up my car. After a few minutes, the fan just stopped. Eventually, I traced it down to a blown relay. When I pulled the relay, I noticed that the relay holder was melted.
I think the relay holder was a cheap knock off but just in case, I’m going to upgrade all of the wiring from 16 gauge to 14 gauge. It shouldn’t be necessary but I’m riding on the cusp of necessity. I also have both the power for the relay trigger and the power for the fan on the same fuse on my fuse panel. I’m not sure if backfeeding is an issue so I’ll hopefully eliminate that. Backfeeding is simply the power finding the path of least resistance to the ground. Which, in this case, might not be though the fan.
Image stolen from: http://www.offroaders.com/tech/12-volt-wire-gauge-amps.htm
The ground for the fan is also on some flimsy peace of metal so I’ll sand that down and upgrade it.
If anyone has suggestions, let me know! I figure this is just step 1 basic electrical troubleshooting.