I put the derale adjustable fan switch on my car today according to the given directions:

1 black/ground
2 red/battery
3 orange/ + fan
4 blue/ + fan 2 (if used)
5 yellow/switch ignition source
6 green/ + ac clutch

I have a few questions about how this went together, but first some background. My car is equiped with dual factory electric fans. The switch came with only one fuse, and they put it on the orange wire. Not wanting to find a puddle were my car was some day, I wired in fuses on the red and blue leads near the switch also. The fuse on the orange lead was a 25 amp'er so I put a similar one in the fuse on the blue wire. On the red wire I put the biggest one they had at radio shack of the same style, with its max amprege of a 30 amp fuse. I blew two of these 30'ers in a row when I first test ran the car. A quick look over all my work for any shorts revealed nothing. Are these fuses I added to the kit nessesary? What would be a better amprege for the fuse that keeps blowing, and where would I get one?



:hail: Thanks for any needed advice!

 

No one knows? Basically all I am asking is how many amps should a fuse be that runs current to both of my electrical fans?

 

Maybe what you have is worn fans. If the bearings are going out and the load on the motors is higher than normal then the amps will also be higher. Worn bearings will increase drag and will put a higher load on the motor. That could be whats blowing your fuses. Thirty amps should be plenty since the highest load is during start-up until the fan gets up to speed but its just temporary. If the fans are worn then this start-up time is extended and the fuse will heat up and blow.
I know this happens in large industrial motors so it might be something different, but you still can't rule it out.
Later,
Ozzy