Voltage gauge going haywire

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Sep 20, 2023 | 01:22 PM

Firs

Thread Starter

Mountain Pass

Joined: Jan 2023

Posts: 144

Likes: 11

Voltage gauge going haywire

Hey y’all, I am stumped. I’m not that good with the whole electrical side of my truck and it shows. Anyway, my voltage gauge is going haywire. It goes from 8 volts to 16 super fast. It’s like it waving to me. It just started as I was cruising down the highway. 70 miles per hour, 2k rpm. I’ve got a 1995 f250 4.9l automatic.
Any info is much appreciated. Thanks!

Sep 20, 2023 | 03:30 PM

OhioFordFarm

Mountain Pass

Joined: Jan 2014

Posts: 214

Likes: 37

From: Madison Ohio

first thing I would do I check voltage with a after market gauge, or better a good volt meter ( VOM tester ) and find out if your gauge is going bad, or problems with electrical system.

Sep 20, 2023 | 03:35 PM

Firs

Thread Starter

Mountain Pass

Joined: Jan 2023

Posts: 144

Likes: 11

I think I can be sure that the voltage is bad because when I went low my dash lights would go dim and my stereo shut off and my turn signals would slow down.

Sep 20, 2023 | 03:40 PM

OhioFordFarm

Mountain Pass

Joined: Jan 2014

Posts: 214

Likes: 37

From: Madison Ohio

Voltage regulator issues, or ALT going bad? loose, poor battery or battery connections.

Advanced Auto Parts and a few others can do a charging system test. This might point you in the correct direction if unsure.

Check cables, and connections first. Ford trucks have a real problem with the ground cable going to the motor. poor grounds can make for major hard to find problems.