I have a '01 Supercrew 4x4 that in the last three weeks has been blowing the 20amp fuse for the turn signals and flashers. I realized yesterday that it blows when the brake pedal is applied. I've checked or replaced related fuses,(none blown), and the tail/brake lights. Any advice would be appreciated.
bdob

 

Is the fuse you are blowing CJB ( aka Central Junction Box, cab fuse panel ) Fuse # 13 ? ( Turn signal fuse is CJB Fuse #23, 10A ).

Confused by the description and the size crossing.

CJB Fuse # 13 feeds directly to the BPP ( Brake Pedal Position ) Switch.
after the BPP switch, this is on to the CHMSL, aftermarket CHMSL, the Trailer Tow stop lamp ( brake controller ) and back around through the MFS ( multifunction switch ) to feed the brake lamps if the MFS is not flashing one of the rear tail lamps ( no turn signals, or the side opposite the turn signal ).

If the turn signals work, I take a guess and say the MFS is OK, but this needs to be kept in mind after some diagnoses.

Some configuration questions

1. Do you can a cap or other that is using the aftermarket CHMSL ?
2. Do you have a brake controller installed ?
3. Do you have something like a line of fire installed ( or similar ) ?
4. Any other modifications ( LED CHMSL as an example ) ?
5. Did you have the recall done ?

With some background info, we can find which way to look.

Let us know

 

Thanks for getting back to me.
The fuse that I have been blowing and replacing is in the cab and #13. I have not checked any under the hood. There is a brake controller that was there when we bought the truck. We had a cap installed and the inline fuses that I have seen are still OK. The turn signals and emergency flashers go out when the fuse blows.
I don't know about the recall.

I hope this helps. Thanks again.
bdob

 

There is a recall for the cruise control
recall 05S28. Description: Speed Control Deactivation Switch.

You can check at the Ford owner site to see if it is scheduled ( should be ) and if it has been done.

Could be a short to the factory cap CHMSL, depends on the size fuse the cap used ( if it is 5 A or 15 A ).

You can disconnect the brake controller, to see if that is it.

Anything with LED CHMSL or tail lights, Line of fire aux light ?

 

I removed the brake controller and the associated under hood fuse. #13 in cab turns signal fuse blew again when the brake pedal was touched. I entered the vin at the ford site and it said no recall on that vin. What is the CHMSL, and where can I check it?
Thanks again

 

Sorry, Center High Mount Stop Lamp ( 3rd brake light on the back of the cab and on the cap ).