fuse keeps blowing,help!

[FLiatsis]

I have a 2004. 5 3500 srw and every time I plug in my horse trailer the 20 amp fuse keeps blowing. The fuse is the one that charges the trailer battery for the overhead and exterior spot lights. It is not the trailer because i have two chevy pickups (gas jobs) and the fuses never blow. When I replace the fuse, the lights work fine all trip long. I went to two Dodge dealers with no luck. I put in a higher amp fuse and that will last a little bit longer. I love pulling with my Commins 600 but I am also fustrated having to replace that fuse every time I tow. any ideas?

 

[wyosteve]

I'll be curious to see the responses also. I have the same problem. If I replace the fuse and don't drive, the lights in the trailer work fine. But if I drive off, the fuse gets blown. I thought it might be related to the electric brake controller, but haven't done any tests yet.

 

[B.G. Smith]

Does thje trailer have a battery for the breakaway brake system, if so how big? bg

 

[Jaysyl]

I found mine blowen. I do not know when this happened. I replaced the 20 amp fuse. I have towed the same trailer and one different trailer, the fuse is still good. Strange why the first fuse burned up. When I park with the trailer hooked up I always try to un plug the truck from the trailer in case I start the generator or plug the trailer in shore power. I do not know if it matters.

 

[FLynes]

Here's the answer, because this happened to me too. I'd be willing to bet that your trucks were running, when you hooked up. That's the problem. Turn your engines off, plug in, then start the vehicles again. I doubt you'll blow a fuse again. I haven't.

 

[jelag]

Flynes has a good point..... but look at this... . could your 2 chevy gas trucks have the trailer connector wired NOT to the industry standard... and your trailer is ALSO not wired to the industry standard... the trailer and chevy's work fine but blows the fuse on the dodge because it IS wired to the industry standard?

 

[JHardwick]

I put in a higher amp fuse and that will last a little bit longer.

Thats a sure fire way to burn up some wiring!!!!



Your trailer plug is not wire correct to industry standards, I've seen this time and time again. It really doesn't matter to Joe-****-the-rag-man how you have them wired, as long as they are all wire the same!



I'd personally change the trailer to match the Dodge, and then change the other trucks to match that ... ... ..... but thats me.

 

[FLynes]

I agree with jelag and JHardwick that your harness could be the problem, however try connecting your harness with the truck off first; it'll save you a lot of headache rewiring everything. I could connect my trailer to my Blazer with it running and no problems... Chevy's seem to be a bit more tolerant about that sort of thing.

 

[Cattletrkr]

If you dont have one of these get one. Mine came from Redneck for around $20. Anyone who pulls a trailer should have one. Such a time saver. In the case specific to this thread, it will tell you which truck is wired properly and which one is the chevy.



Before I rip on the chevy's too much, do they have factory wiring or did "a guy in town who does a lot of them" do it? Dad sells trailers and we also install hitches and controllers etc. You would be amazed at some of the hack jobs we run into. Those emulaotors save us a lot of headaches when guys try to insist that it's "your trailer, not my truck". We just plug it in and smile when we say "we'll fix the trailer for nothin', but it's $50/hr to screw with your truck".



Sorry, but I don't have an answer to your question. My truck managed to burn thru the little 4-way plug that we used when we made an extension for the 7-way. Long story short (no pun intended), weird things can happen.

 

[FLiatsis]

thank you

thanks for the quick response, I have plugged and unplugged about 25 times for the past three days. I have not blown a fuse with the truck turned off. I hope the reason Dodge could not find the problem was that they were working on the truck and trailer with the motor off. Again a big THANK YOU to all. I should of posted this thread two years ago.

 

[wyosteve]

Big thank you to FLynes. I too have used the 'plug in with truck off' method in the last week and have had no problems. Membership paid for itself again!!

 

[bighammer]

Big thank you to FLynes. I too have used the 'plug in with truck off' method in the last week and have had no problems. Membership paid for itself again!!

Very strange. I'll try to remeber that... .

 

[starkmr]

Truck running or not should not be a problem. Because this seems symptomatic, it leads one to believe that there is still a problem. I would get the test unit, or one similar, as shown above and fix the problem once and for all.

 

[FLynes]

The problem, as I was told by a Dodge tech, is that you just can't plug a trailer to a Dodge while it's running. There's no rhyme or reason to it, that they can explain. They've seen this problem dozens of times, and that's the solution. Since it works, and it's a free fix, and it causes no further harm to the truck or trailer, I'm sticking with it. Glad it worked for other folks too.

 

[raychem]

I want two add my $ . 02. I don't tow like I did years ago when I had my 96 Chevy crewcab (private transporter). But I would like to say that since they stared to manufacture the 3rd gens, Dodge went to the same system that mercedes uses. The old system worked on 12 v triggers and relays, the new system uses single wire resistance so that the ecm controls or is aware of what is going on and can sense when somthing is wrong. If you ever had a head lamp go out, you get a lamp out idiot light b/c the ecm measures the resistance in the wire that feeds the headlamp and since the resistance values change when the lamp is out, I can let you know. I think it is the same with the trailer wiring. With the truck running, you indroduce a load that the ecm is not expecting and acts to protect the circuit. Hence why the fuse blows out but the capacity is there in the system. Just a thought.



Richard