Trailblazer wiring issues

[OPIE]

What are the odds that the plug on my wife's 2002 Chevy Trailblazer was wired wrong from the factory? I ask because I had used a different truck to tow our T-1550 last year, and when I was doing maintenence, I plugged it into my Jeep with no issues, but last week I had my wife's Trailblazer, which will be my tow vehicle for local trips this spring. I always do a walkaround and quick check of the trailer because it's not parked at my house. When I did this with the Chevy the running lights wouldn't work and the turn signals both blinked together, and no brake light. I checked all the obvious stuff, plugs, fuses...but no good. So I got the Jeep and everything works again....so I'm pretty convinced the problem is in the Trailblazer. Any suggestions?

[chuck & lori]

There is a similar question on the RV.net forum (in the travel trailer section). It seems that this guy's new F-150 and his new trailer are wired differently. Based on his research the truck is not wired as RV's are typically wired. The discussion includes several photos of wiring diagrams and also links to several web sites with additional information on how the 7 pin plugs may be wired.
So, if not "wrong" possibly it was just wired different.

[JohnB]

Opie

Do you have a voltmeter or a 12 VDC test light? If so let us know we can help you ring out the connection of the 7 wire recptacle on the back of the Trailblazer.

We have a 2003 TB sitting in the garage. I do know the 7 wire to 4 wire adapter works a standard utiltiy trailer, no brakes. GM use to have on the outside of the snap over cover what each pin was for. And in the owners manual it use to tell what pin did what.

With a meter we can check that all 6 pins around the outside go where they are suppose to.

Basically clip the meter to ground on the truck then use the other meter/test light lead to test each pin with just the truck on with parking lights, brake lights, directionals. If it is wrong, it should show up.

What you describe does sound like something in the truck is mixed up but the meter will prove it is.

Hope this helps

John

[OPIE]

OK - that's what I thought. I guess I'll spend some time getting to know the Trailblazer better as soon as the foot of snow is out of the driveway.

[Randy Gulley]

Hey Opie,
The first thing I would do after plugging the Trailblazer to the TT is connect a separate ground wire between the two vehicles.
If you don't have a good ground or no ground at all, then the lights all feed back through each other to ground.
Randy

[OPIE]

Good call, I'll try that first.