2000 4 Door Headlights Fuse Keep Blowing
 

Last week driving at night my headlights just turned off, turned out it was just the 10 fuse that was blown. I replaced it and was fixed, until last night again at night fuse blown! Replaced the fuse 2x and both time's when starting the truck fuses were blown. Any insight would be appreciated!

There are three different 10A fuses involved in the headlamp system, which one keeps blowing?

George

https://cimg5.ibsrv.net/gimg/blazerf...829b1c85e2.jpg
#7 is the one that keeps blowing

That's the HDLP SW fuse which is the power for the headlamp switch for the headlamp portion of its function. This power is routed through the switch to the headlamp power relay and switches ground to a headlamp control input on the BCM.

So this can be:

1. The headlamp switch itself is failing
2. The headlamp relay is failing
3. The BCM is failing
4. There is a wiring short from power to ground in a few candidate locations in the related wiring

There are a couple of ways to approach this but since they are cheap and easy to replace I would start with the relay first and then the headlamp switch. If thats not it then we have to locate the short to ground. I dont usually like starting with the parts cannon but detailed diagnostics will involve amp probes and cutting wires so trying those two parts are a reasonable first step in this case. If you would rather begin with a proper diagnosis I can help with that.

George