Electrical help

[qnz]

I have a volt gauge in the car and it reads my voltage is normal when The car starts up (14.0-13.7v) but after driving for an hour or so, it will be reading at 13.0v. I test with a multimeter at the different sources and my multimeter confirms what the volt gauge reads.

However at the battery, it still reads ~13.8. When I measure at the fuse box and at the constant power at the radio, it reads the same ~13.7.

Why would the reading at the accessory power (where my volt gauge is tapped) read different from the main power? Aren't they coming from the same power source? What would account for the voltage drop while driving also. I changed the alternator thinking that was it but it didn't fix the problem

[qnz]

Can't seem to edit from tapatalk.

Also want to add that car has never shut off or done anything funny. If it wasn't for the gauge, I wouldn't suspect there was anything going on. Is there anything going on?

[oakrdrs187]

I wouldn't worry about too much. It may just be the regulator on the alternator adjust to a fully charged battery.

[keith6110]

Maybe your accessories (radio, climate control, headlights/corners/tails, ecu, etc) are using .7v when tapped from your accessory wire?
I would have changed the alternator too if I was concerned. Sounds like everything is running fine to me.

Do you have slow starts compared to "normal"?