My '98 3 button lights seem to flicker constantly. When they do stay on, I can switch between any mode without problem. It has gotten worse and worse over the last year. Many times I'll have no lights at all. All the searching I do nets me questions about lights that seem to have a controlled blinking where as this is clearly something screwed up. Would the TCCM be causing this or is it just that the dash switch is bad? Thanks

 

I would almost say for certain it's the dash switch at fault. Mine was doing the same thing & I replaced the it & the problem went away. If I tapped the old switch while driving the lights used to sometimes stop flickering & the switch then worked normally. I put a new Dorman one on as it was much cheaper than a genuine GM one. Mine is a UK market right hand drive model & the switch is the same one that is used in the US market Silverado but I notice on the Dorman website that they sell all the US market switches too.

 

Thanks for the input. I think I'm going to try that then. I've read of them going bad but I haven't seen anyone describe what I have happening.

 

Got the new (used) switch in and it does the exact same thing. I have a hard time believing it's the switch now. I have tried shorting the #13 pin and only come up with a code 1 which I understand really doesn't mean a lot. I've checked voltage at the TCCM outlined in the NV233 No Mode Switch tech article. I had very minor corrosion on the two end pins of my TCCM but I cleaned them up and coated them with dielectric grease. When my lights stay on, I have no problem whatsoever switching ranges or modes. This seems to be clearly an electrical or sensor problem vs. a mechanical one. When I was checking voltage and grounds, the dash mode switch was working properly. Do I need to test all of this when it's not? Its hit and miss so I don't know if I'll ever be able to just stop in the middle of driving and test it. Any ideas of what this is? What would cause my lights to flicker like this or totally blank out? PLEASE HELP! Thanks