Trailer Brake Fuse Blew Again

[Dieselnerd]

A couple of months ago I posted that I had blown the 30 amp trailer brake fuse in my truck. I received some good suggestions on what to check. My trailer is a 2006 but I went over every piece of brake wiring twice and it was perfect. I opened all the 7 pin connectors to make sure there was no little piece of wire shorting between terminals. All good. New fuse and hooked to trailer, everything worked fine.



Two days ago, on a trip, my BrakeSmart started beeping just after I parked in a campsite. It said on the display "Truck Battery Low". I reset it and it came right back. I stepped on the brake and the fuse blew. I'm assuming it thought the truck battery was low because the brake line was shorted at that time but didn't draw enough current to blow the fuse until I stepped on the brake.



Here's the thing, I wasn't towing my trailer, I had my slide in truck camper which doesn't use brakes. I wish I had pulled the plug before I stepped on the brake just on the off chance that the camper was somehow drawing brake juice.



I put in one of my spare fuses and the problem was gone again.



I'm going to remove the brake wire from my camper power cord just in case but I think the problem must be in the truck. I haven't really checked much on the truck since I thought it was a trailer brake problem. That's where I'll start when I get home again.



If anyone has any other ideas, I'm all ears!!

 

[JAshpaugh]

You might try checking all the grounds and neutrals. DC voltage is weird and if things aren't grounded properly it heats stuff up and fuses start popping. My 07' Weekend Warrior 5th wheel was popping a 30 amp fuse at will. Come to find out that all the grounds and neutrals were loose. Just a thought. . Good luck,, those electrical gremlins are tough. .

 

[jelag]

You could have a problem in your brake smart... ... have you given their tech support a call.....



This doesn't fit here..... but let me share this with you as we chased this for months...



Our trailers with electric brakes have wires that run from one side the axle to the other side through the axle..... We kept blowing fuses... ... and chased this for 2 or 3 months... finally in a fit of rage I ripped all the wiring out of the trailer and started from scratch..... as I pulled the wires from the axle... . I found that the wiring has rubbed inside the axle while the trailer was going down the road... and wore through the insulation..... as it would bounce around it would short out... . of course the brakes had to be on... . and it had to bounce just right.....



I carried the wire to the guys who supply us axles..... the group of guys sat there and were amazed that this could happen... ... we ran new wires outside the axle and we've had no problems since than.....

 

[Dieselnerd]

Good idea Jim, I didn't really think of the BrakeSmart itself but I'm sure it's possible. I'll get in touch with them to see if they have had this problem before.

 

[Dieselnerd]

Well I'm still on the road. Problem is getting worse, the 30 amp brake fuse and the 15 amp fuse from the brake switch both blow after about 100 miles after the BrakeSmart gets good and warm and I step on the brakes. No trailer attached and no indication of a brake wire short which is an error condition supposed to be displayed by the BrakeSmart. Only place both of these feeds come together is in the BrakeSmart. Wish I had a schematic of the unit. I have not talked to BrakeSmart yet. Bought mine from the Old Master Brake that doesn't make them any more. I doubt Dr. Performance will be interested in my old, out of warranty unit. I may have to buy a new one...

 

[HBarlow]

You may be pleasantly surprised if you call Dr. Performance. My BrakeSmart was purchased about three years ago from Master Brake also. When a mechanic friend and I moved all the equipment from my '01 Ram to the current one in April he accidentally plugged the large plug on the back of the controller into the wrong slot. I experienced weak trailer brakes. I called Dr. Performance and received polite and helpful suggestions that led me to find the problem. My controller has close to 300k miles of "experience. " Master Brake replaced my BrakeSmart twice at no charge due to minor quality control issues early in my experience with the product. I haven't asked but I would expect Dr. Performance to be helpful in the event of a failure. I wonder if they have some sort of return and repair or refurbish program in place? It would be worth inquiring.



If mine eventually fails from long use I'll attempt to get it repaired at Dr. Performance or exchanged for another unit but I will happily pay the full price for another one if that is what is required. Nothing else currently available can be compared with it.



Harvey

 

[Dieselnerd]

Thanks Harvey, good to know about Dr. Performance. I've sent their tech support an email describing my problem and asking what my options are. Since this is the weekend I don't expect an answer before Monday at the earliest. I'll let everyone know what happens after I get an answer.

 

[Hoefler]

You might try replacing the fuse with a self resetting breaker, at least it will reset it self and you have some kind of brakes until you get it figured out.

 

[Dieselnerd]

I've been looking for such a breaker, they are available for GM and Ford but so far nobody seems to have one for a Dodge. I only use my fifth wheel from December until the end of April as a winter home in AZ so I still have plenty of time to fix the problem. I'm about 99% certain the BrakeSmart controller is the problem.

 

[Dieselnerd]

Another update, on the road again today, only drove about 200 miles to next destination. As an experiment I only replaced the 15 amp fuse that supplies the 12 volt signal to the BrakeSmart and did not replace the 30 amp main electrical brake fuse. The BrakeSmart had no power that way but it still displayed the PSI when the brakes were applied. After about 150 miles, that fuse blew. The only place that particular line goes is the brake controller, period. I do have the full Dodge service manual with me and looking at the wiring diagram, if that fuse blows the brake controller is the problem or the line to the controller from the brake switch is shorted. To prove that, next I'll replace that fuse again and disconnect the harness to the brake controller. Fun chasing electrical gremlins.

 

[Dieselnerd]

Update on my problem for those with BrakeSmart controllers that may be following my progress in isolating the cause of the fuses blowing. I just got an email from Dr. Performance and was very pleasantly surprised by their reponse.



Here is part of what they had to say:

"This is indeed an unusual concern I have not seen this type of issue before, I would like to examine the Brakesmart to determine what may be causing the issue. If you would please send me the controller and include on the box RGA #107, we will determine what is causing the issue and make sure that you have a good working unit".



I would say that this is unusually good service considering my unit is out of warranty and I didn't buy the unit from Dr. Performance.