Originally Posted by mmoore6856
one extra note the ammeter is completely separate from the other gauges as it does not ground on the dash actually does not ground at all for it to operate. the only ground it needs is for the dash lite
I was gonna add this -- glad you did!
Even quality after market gauges are often only accurate +/- 10% --
That means a temp reading of 200°F is anywhere in the range of 180° to 220°F... PICK YOUR RELATIVITY METER WISELY...
Gas gauge especially will work off a specific ohm range -- no such thing as a universal replacement electrically speaking
the universal part is adjusting the float arm swing to your fuel tank...
And does an '88 GMC really have an ammeter gauge?! To be accurate that means all the buses alternator output passes through
that gauge. This design is why so many IHC Scouts have electrical fires...
The other gauges will go through a CVR and if that's bad will be the source of all the gauges being bad.
A good wiring diagram of the truck will tell you how that's handled.