Turn signal problem!

[Dale M]

I have a 1977 27' Landyacht that I purchased last summer. The AS had not been towed in many years so the pigtail from the truck to the trailer needed to be redone so that my 2004 Duramax trailer connector matched the wiring input to the trailer. I read the AS manual and spliced the new cord to the old cord and all was well. The AS lights ( stop, signal, running) seemed to work just fine.

On our first trip this summer I did the walk around to make sure the lights worked and to my surprise the the left signal made both sides blink! The right signal worked fine. And when the brakes are applied only the left brake lights came on!? I checked all of the bulbs and they are fine as sometimes a filiment will break off and lay on the second brake light filiment and make a false circuit to the other side. I checked the truck and found that it was sending a signal out of both the right and left signal pin on the 7 pin connector on the truck. I was sure that the truck was the problem. Today the Chevy dealer sez that the truck is working fine and that he can find no problems!!

Any ideas as to what's going on? Thanks for the help!

[jimmickle]

The first thing to do is confirm that both the TV and trailer are properly wired. If you go to the Bargman web site and download the catalog, http://www.bargman.com/catalog.pdf, you will find the connector diagram on page 38. Using a test light, determine if the tow vehicle is sending the power to the correct terminal, and only that terminal. When the left directional is on, only the left stop and turn should be hot. Same for the right. When the brake is energized, both the left and right stop and turn should be hot. The electric brake terminal will also be hot when the brake is energized. If all that is correct, set up a battery and jumper wires, and see if the trailer lights correctly.

From what you describe, the wiring on the truck is likely the problem. I assume that the pigtail that you changed was on the trailer. Am I correct?

[overlander63]

Does your Silverado have a separate bulb for the turn signals? If it does (and I think it does) you could have a bad converter on your truck from five filiments to four. This converter is on the right rear inner fenderwell, and they seem to have an issue.

[jimmickle]

After more thought, and re-reading your original post, I am sure that the problem is the TV. Dealers are notoriously incompetent when it comes to electrical. Because of the flat rate system, a technician that becomes known as good on electrical will starve, so even if they understand electrical, they try to keep it well hidden. I suspect that Terry has hit the problem.

[Dale M]

I picked the truck up from the dealer yesterday p.m. and I tested the plug right there in the parking lot and it was working as it should. So I drove to my daughter's house and connected it to the trailer and everything works fine!? I still think it's a truck problem because it did the same thing when I connected it to the uliity trailer, which is a year old, last week. I'm going to look for that controller on the firewall as I suspect that's the problem. The brake light and signal are on the same light bulb in the 2004 model. Thanks for the insight/help. Going to Fergus Falls Minnesota for the family reunion and staying in a wonderfull state park.

[jimmickle]

While they are expensive, a factory service manual can be a savior when you get into something like this. I always get one for any vehicle I plan to keep for a while.

[dwightdi]

GM service manuals are now on CD's. Copies can be had cheap off Ebay, if you have the hard disk space to store them. There are also two different harness adapters for the Silverados (depending of the year) and if the dealer installs the wrong one the result will not be good.