Trailer connection problems

[frankraney]

Originally Posted by cmysstailights

Had this happen on my 15 2500 silverado. Did you have the inverter on. I noticed mine came on more frequently when i had the inverter on. Im guessing its a battery drain issue cause it always happened after about 2hrs of driving.

I didn't think of this... Don't know how to turn off the inverter.... Have to check it out cause mine is doin the same thing...I can take off and all is fine then anywhere from 30 - 60 minutes, it starts acting up......I also noticed my battery in the right is weak (time to replace) I wonder if that might cause it.

But that still doesn't explain why the brake output is intermittent with out the rig hooked up my that appears to be a problem in the truck wiring.

[dodgemark]

Originally Posted by Homebrew

BK in this case means Black

Which is wrong. Black. Is blk

[aeblank]

Originally Posted by dodgemark

Which is wrong. Black is blk

It's the label on his tester. Relax.

[aeblank]

Originally Posted by frankraney

I didn't think of this... Don't know how to turn off the inverter.... Have to check it out cause mine is doin the same thing...I can take off and all is fine then anywhere from 30 - 60 minutes, it starts acting up......I also noticed my battery in the right is weak (time to replace) I wonder if that might cause it.



But that still doesn't explain why the brake output is intermittent with out the rig hooked up my that appears to be a problem in the truck wiring.

It'll not output brake voltage if there isn't a trailer there. I think it uses the resistance on the brake line. Not sure what it does if there's no electric brakes.

I still think you have a trailer wiring issue. 90% of the time, that's what it was. Many similar threads.

Can't imagine why battery voltage would matter. It shouldn't drag down the electric brake circuit. I'm interested in the theory on this one...

[TheWolfPaq82]

My old Jayco did this the last year we owned it and hooked to my Chevy 1500. Turned out to be the connection under the truck at the factory plug. Tore it apart and the line had corroded badly. Pulled the wire out of the plug, cut end off, restriped the wire, cleaned terminal in plug and if fixed the problem. That was after spending 1-2 hrs under the trailer going thru all the brake wiring to each wheel. Took about 20 minutes to repair the damage at the plug.

[dodgemark]

Originally Posted by aeblank

It's the label on his tester. Relax.

Wow. Never said I wasnt

[Wileykid]

Although I have a newer Chevy, I was having "service trailer brake", "trailer disconnect" warnings. Ultimately the problem was located in the trucks trailer plug. Weird voltage issues, and corrosion was found. The plug was replaced, filled with dielectric grease, and no issue's since.

One thing you can do if you think it is the truck, is the dealer has the ability to test the trailer plug (plug in a trailer simulator), and systems associated with it. May not be cheap, but may resolve the issue quicker.

[jayrodoh]

Originally Posted by frankraney

But in order to trouble shoot I needed to know how pin 2( breaker output) works. Is it a ground or a hot wire.

I noticed this has yet to be answered, it is a hot or positive wire. The brakes are grounded through the trailer. Most trailer brake wires are blue on the trailer itself.

[frankraney]

Originally Posted by Chuck_S

I have the Tekonsha 7 pole tester but it won't fool my Ford into thinking there's a trailer attached. Probably because the indicators are LEDs with very low current draw.

Did you upgrade to LED lighting? Seems like "everything" comes thru the car's computer or one of the several computers embedded in the car. Putting LED lights on a trailer will confuse these systems as well. If LEDs are used in lieu of conventional bulbs many if not most ECUs will indicate a fault or "fast flash" on older systems. There are LEDs which don't cause this. "CANBUS enabled" or similar name and they have additional resistance in them to fool the computers. Replacing all or several conventional bulbs with LEDs could easily fool the trailer into thinking there was nothing attached back there. Tail lights? Nope. Marker lights? Nope. etc. Ummmm, nothing back there. Trailer must not be there either.

Don't know about GM cars but I can access the computer in my Ford with software and do things like disable "fast flash", activate Daytime Running Lights, extinguish bright indicators on the panel, etc. We're not driving these, the computers are running them for us.

-- Chuck

No light circuits go through the computer. The only thing that goes through it is the trailer brake circuit. This is how the truck knows a trailer is connected. The truck sends a small current our on the brake circuit xx and if it comes back, "trailer connected" is displayed.

Etrailer told me the tester would and exactly like a trailer.... It will not. This tester is only for testing the circuits, that they are working right. But the truck sends out a pulsing current looking for the brake, this why the brake (BK) light flashes, according to etrailer. So, since I am only having a problem with the brake circuit, looks like I got sold a useless bill of goods. This tester does not, and is not made, to TROUBLE SHOOT. It only proves connections are right, which i already knew we're right, it ran for 6 years..