Voltage Issue - '97 K2500 7.4L Suburban

[MartyW]

Hi All,

The dash volt gauge on my burb shows 13.5 volts with no accessories running, and it shows 12.5 to 13.0 volts with front + rear a/c and bright lights turned on.

I just got it back from my Chevy dealer this afternoon and they say that all is ok with the voltage (solid 14+ volts when they measure it with & without load). Alternator has been replaced with no noticable difference and they say battery cables are good. There is no sign of corrosion anywhere and connections are good.

I'll call Monday and ask to speak with the tech to be certain, but I would imagine that they are measuring voltage at the battery or at the alternator.

We have a long trip planned for June so I'd really like to get this corrected if possible. Any ideas from folks with similar type GM truck much appreciated.

Many years ago I had an old Fiat with a similar issue and after replacing alternator multiple times and replacing battery cables, it turned out to be a wire with corrosion between the ignition switch and the engine. I searched high and low to find someone who could identify that problem and that fellow is retied and gone now.

Thanks in advance,
Marty

[MartyW]

Many thanks Norway and Fulltimer for your inputs. Much appreciated.

Newman, the trans shifting and a/c blowing are good. Can you please explain in a little more detail if possible. I can get a price on Monday for replacing the ign switch.

[newman_fulltime]

The ignition switch is known in those years to go bad the ground termanal in them gets worn down .The biggest thing it effects is the trans shifting if the ac stops blowing this is what hapens when it breaks.I have had a suburban and a truck in thwt year model do it

[Son_of_Norway]

It could be a problem with the dash unit gauge. The dash units are a one-piece assembly and you have to send them off to be repaired. I did it on one of my sons' GM vehicles. Good luck with your repairs.

Miles