Electrical Gremlin?!?!?

tomrex · May 6, 2005

Ok, here's the problem...98k on the clock and not one penny put into this truck, so I can't complain. Maybe someone can help. Got into the truck the other day, started it and took off only to realize that I had a christmas tree array of lights on the dash. I have permanent ABS, Air Bag, and flashing seatbelt (probably cuz i don't wear it). The message center was flashing Battery, Low Fuel, Security, and something else. I also noticed that the trans temp gauge, water temp gauge, fuel gauge, and the transmission selector indicator not working. I thought, what the hell, so I turned the truck off and back on and it was gone. It came back today and lasted longer. I did some poking at wires, relays, fuses and nothing good. I started driving, vitals were good...oil PSI, battery, speedo, tac, odometer...but the same things were on and off. The cruise works, and everything inside...but the same lights were on and there. 10 minutes later, i restarted and they went away. GRRR... does anyone know if any of these are on the same electrical circuit or have a diode or something? Any help would be great. Thanks a million!! Tom.

GM-Tech · May 7, 2005

No, your alternator is not the cause of this problem. Even if the alternator went totally dead, the battery would provide the needed voltage until you ran that down too. At that point, you'd be dead in the water, need a jump start, and it wouldn't continue running unless you left the jumper battery connected.

The pulsing lights you're seeing is actually another known issue. It's not harmful, but if it bothers you, it can be corrected by adding some additional wiring to the alternator.

GM-Tech · May 6, 2005

Ignition switch. The PRNDL indicator missing in action is the key here.

Wingnut · May 6, 2005

And start wearing your seatbelt, or I'll call your mom.

tomrex · May 6, 2005

Is this a hard one to change? Any tips on doing it? It's not the cylinder, it's the switch behind it correct? Thanks a million for your help. Tom.

By the way, I'll make sure to keep that belt on from now on...mamma wouldn't be happy!

tomrex · May 6, 2005

I had the same problem today and took down some more information. The gear selector/odometer screen doesn't dissapear, just the little box that tells you what gear you are in. Also, when you turn the key off, the security light blinks in the message center and then becomes solid. You can set the alarm with the remote (like when the light is supposed to be on) and the alarm still works. When you unlock with remote or key, the light doesnt go away. This is the only reason I wouldnt suspect the ignition switch. Let me know what you think...Tom.

rascal · May 9, 2005

could a bad ground wire cause that?

tomrex · May 9, 2005

you know, thats one of the lines that I was thinking...a bump could set the dash off, it's all up in the air...but it's been two days and nothing yet. It's kinda weird, driving along at night and all of the sudden the whole cab lights up. Wakes you up better than a cup of coffee! Thanks for the reply, I'm going to start checking ground straps. What's weird is it happend right after I had a tire store (pickup and deliver back) change the tires...I wonder if they bumped a strap off when they lifted it...It's a shot in the dark, but I'll run with it!

GM-Tech · May 6, 2005

If just the position indicator disappears, that sounds more like a neutral switch problem. But you have so many things going on that it's hard to say for sure.

Need to do a little diagnosis, otherwise you might as well just flip a coin and call it to determine what to replace.

tomrex · May 6, 2005

The only reason that I don't want to replace anything yet is that it all happens at the same time. If ten thousand lights are coming on, and the selector indicator goes away...that tells me that it is more than a switch. I don't think that the neutral switch would be connected to all of those other things, would it? I think that there is a reason that it all happens at once...like a wiring harnes is chafing something. To add to the story, today I disconnected the battery for 2 hours. The truck didnt want to run at first, which is ok by me because it needed to learn it's settings...but the problem hasn't re-appeared. I don't think it's gone, but I drove 95 miles today and got nothing abnormal. Oh well, keep driving... Thanks

underpressure · September 20, 2006

Just wondering, I've got the exact same problem,and was wondering what the fix was.intermitant problems are never fun. thanks!

tomrex · May 7, 2005

GM-Tech, would you say that it is possible that my alternator or internal voltage regulator could be causing this goofy crap to happen? At a stop, i can look at my headlights or dome lights and see a quick but faint dim-light-dim-light...situation, like a fast pulse. Would you think that this could be contributing to the siteeation? It has not done this in the past and recently started it and I never thought anything of it 'til now. My voltage on the gauge is good, but i suspect it is time. Every chevy/gmc truck that I have owned has needed an alternator. Let me know your thoughts. Thanks!