High beams won't work, what's the most likely problem??

[KingpenM3]

A few months ago I couldn't get my brights to work, then they would work after the truck warmed up, but then they would only work if I pulled the stalk, but then they worked fine, and then they would work if I jiggled on the stalk, and now they won't work at all. I tried to see if the relay (#70) was working, and with the key on (engine off) and the headlights still off in "auto", when I "pulled" the stalk, I could feel and hear the rely swapping, but when I turned the headlights to on, and pulled the stalk, the relay didn't work, and the lights didn't swap to bright. And now the "bright lights" indicator light never comes on (except on startup). So seeing how both lights were working fine before, I just don't think it is a bulb or fuse problem, doesn't seem to be a relay problem. I was pretty convinced that it was a multifunction stalk problem, until the stalk started activating the relay today. So I'm lost. It's just like something somewhere is telling that relay not to switch over when the low beams are on. Anything else that could be causing my problems? Any thoughts on what the most likely offender would be? Thanks!

(now that I think about it, is it possible that a troubled relay could switch when it doesn't have power to one side, but then not be able to switch over when power is going through the first side? Suggesting I have a relay problem?)

 

[SedonaBound]

Swap in a known good relay to be sure it's not the relay.

 

[rsc]

Relay is the cheapest, but I bet if you jumped the wires at the stalk connector you would find the stalk is corroded up and bad.

 

[KingpenM3]

Swap in a known good relay to be sure it's not the relay.

Thanks for the suggestion, you saved me a trip into town! But... it wasn't the relay. And I just didn't think it was the stalk because the Flash to Pass was still working. So after some more reading, I found that there was one more step in the process, the Body Control Module. I really hoped it wasn't the BCM, because from what I had read, not only is it a couple hundred dollars, but it required a dealer reprogramming as well. But I wanted to check and see what I would find if I went down into the pass kick panel to take a look. What I found was a broken "locking handle??" on one of the plugs to the bcm. How this could possible be broken off I have no idea. It was only broken on one side, so I unplugged it, plugged it back in and got it to lock as well as I could, checked the lights, and sure enough, they are working again! So I guess the answer was faulty wiring into (or out of) the BCM. Boy this thing seems to be falling apart since it hit 100k miles. Thanks again for the help/suggestions!

eta: here is a great pdf that has all the wiring diagrams for the h3: http://schwarttzy.com/wp-content/uploads/2013/01/Hummer-H3-Wiring-2008.pdf

eta: and here is another good page for bcm info: http://www.justanswer.com/chevy/653...-5l-colorado-driving-down-road.html#re.v/150/

 

[rsc]

Glad to hear you got it working

 

[KingpenM3]

Glad to hear you got it working

Thanks! It will be interesting to see just how long the "fix" works.