[Jpaolino]

I just bought a 03 SUBURBAN 171,000 miles. Was driving it home and noticed it starting to overheat acting almost like the thermostat was sticking so I pulled over let it cool down so I could make it to the parts store. Once I turned it back on my voltage gauge is pegged out above 19 and my temp gauge is completely upside down, now at this point I don't know it that was what was going on so I replaced the thermostat anyways. So wasn't sure where to start with this. If anyone could give me advice I have a 500 mile drive tomorrow back home so I would love to have my temp gauge at the least fuctioning.

 

[silverado002]

Wow. That's crazy. I would try disconnecting the battery for a bit and then reconnect it to see if the logic circuits in the dash reset. The temp gauges are driven off the PCM with inputs from the temp sensor in the engine. The voltmeter responds to the PCM with an input from the alternator. Since the voltage was pegged too you could have a charging system issue. Aside from this it could also be a fault in the dash/instrument panel

 

[Jpaolino]

Wow. That's crazy. I would try disconnecting the battery for a bit and then reconnect it to see if the logic circuits in the dash reset. The temp gauges are driven off the PCM with inputs from the temp sensor in the engine. The voltmeter responds to the PCM with an input from the alternator. Since the voltage was pegged too you could have a charging system issue. Aside from this it could also be a fault in the dash/instrument panel

So I unhooked the battery my voltage is back to normal now, temp gauge is still sticking straight down

 

[Cowboytrukr]

Probably the gauges starting to die.

 

[Jaercole]

Maybe replace the temp sensor?

 

[Jpaolino]

I took apart the dash and got to the gauge it looks like it wasn't working properly and the gears were stripped , I just don't understand why my voltage meter decided to do the exact same thing at the same time

 

[MrShorty]

When my daughter's '04 Impala did this, I looked into it and it seems to be a common problem for many (most/all?) GM vehicles of this era. Something about the stepper motors that drives each dial goes out. If you are good with electrical, it is supposed to be fairly straightforward (once you get the dash torn apart -- if that is ever straightforward) to replace the stepper motors (of course, since this is common, replace all of the stepper motors while you have it apart).

 

[Jpaolino]

When my daughter's '04 Impala did this, I looked into it and it seems to be a common problem for many (most/all?) GM vehicles of this era. Something about the stepper motors that drives each dial goes out. If you are good with electrical, it is supposed to be fairly straightforward (once you get the dash torn apart -- if that is ever straightforward) to replace the stepper motors (of course, since this is common, replace all of the stepper motors while you have it apart).

Yeah it took me about 10 min fairly easy compared to other car makers to get the the stepper motors. Just waiting on them now so I can replace them all

 

[Jpaolino]

Yeah I ended up buying new ones and sautering them in works great now

 

[Vegas Avy Guy]

I know I'm a little late but it's probably the stepper motors going out in the gauge cluster. The same thing happened to me. But it was my temperature gauge was pegged, and my speedometer gauge on the freeway was saying I was doing 15 miles per hour. I just replaced the whole cluster, but that was expensive as ****. ($425). If you're handy with a soldering iron they sell the stepper motors pretty cheap.

 

[Jpaolino]

Yeah 30 bucks from Amazon they work great now