Hey guys- figured I'd drop this question in hopes someone has heard of this one and can point me in the right direction for a quick fix. My '04 F-250 out of the blue has started blowing the 20A #18 fuse for the turn signals. It did it about a week ago and I found & replaced the blown fuse. On the way to work this morning I noticed it is blown again.

Is this a known issue? Any tips on what to check would be appreciated!

 

No bites?

Figured I'd top this thread and point out that it also appears that when this fuse blows I also lose my brake lights. Does this scenario sound familiar to anyone? I know my way around electrical fairly well, but there's a lot of possible culprits here so I was looking for any tips on known points of failure.

 

Any towing?

I would start by pulling all of the bulbs and checking for corrosion.

 

Thanks for the reply.

No towing lately- and none at all since this issue has started. I'm blowing fuses very few days now, but I can't pinpoint when it happens. Basically I'll be driving, go to use a turn signal and it won't work. So I'm not sure if it's blowing when I first hit the turn signal or if maybe something on the brake light side is popping the fuse.

 

Definitely pull the taillights and check the connectors for corrosion, then pull all the turn signal and brake light bulbs and check those sockets for corrosion. Don't forget the high mount brake light.

But I would check your trailer plug and wires first. Check the plug for corrosion and check the wires behind it for chafing or damage that could cause a short.

 

Thanks- I'll check that out.

 

If you have a trailer brake controller, disconnect it and see if it still happens.


Ed

 

UPDATE: good call!

I unplugged my Prodigy brake controller the day you posted this and the fuse hasn't blown again yet. Seeing that I was losing a fuse every few days before I'm going with this as the issue.

What made you go with this? Is this a known issue? Is my brake controller defective or is this just something that they do at times if a trailer isn't connected?

 

there could be a short somewhere in the trailer brake controller wiring id check for any corrosion or problems with the wire