Gauges reading funny

[mexicanjoe]

Guys my '89 F-250 gauges are reading a little low, especially the volt mete. I have a new alternator and regulator. I when I activate my a/c the voltage drops to about 11 or 12 volts.....however when I placed my digital handheld volt meter it reads 13 volts... this handheld voltmeter also reads 14 volts at idle when I attach to my battery.... so I know im getting plenty of power...... my question is: how can i repair the volt gauge in the dash? its not a big deal but i would like to know my true voltage. your humble servant awaits your educated answer!

 

[DaveBen]

The gauges in your truck are idiot lights. The gauges read what the truck's computer tells them to read. REAL voltage has nothing to do with the Volt Meter. Replace all of the gauges, except the fuel gauge, and you are GTG.

 

[gandalf]

Right, the Ford stock gauges are just fancy moving idiot lights. They bear little resemblance to reality. If you want accurate readings you've got to replace them with aftermarket gauges.

 

[Cubey]

There are very expensive aftermarket cluster replacements ($600+) that give you all aftermarket gauges, including tach and speedometer which may look cleaner but I'm sure not gonna shell out that kind of dough..

These for 73-79 trucks and 70s-91(?) vans are $675 but sure look nice. Not sure how you would tie in the mechanical speedometer cable to the electronic gauge it seems to come with. Maybe there is a sending unit that replaces the cable.
https://www.egaugesplus.com/73-79-ford-direct-fit-packages.html

 

[IDIBRONCO]

I never did see the needle move on the factory volt meter in my 1985 F250 until I did the 3g swap. NOW that needle actually moves every time I start the engine.