My volt gauge is jumping around

[TN farmer]

I noticed on the way home tonight that my headlights would flicker almost like going from hi to low beam then back to hi. So I looked at my volt gauge and it was jumping from 13.5 to 16 and back.

My question is do I start by checking the alternator or where would y'all suggest starting?

 

[Hedgehog]

Check your ground first.

 

[Torxhead]

Yeah, I would think you have a loose or broken wire like at the battery,relay, or alternator. Could even be a bad fusible link.

 

[Jimbos76cj]

I would also pull the altenator and have it checked.. could be a bad regulator in the altenator.. Most of those parts can be purchased and installed alot cheaper then the cost of a new altenator. Any quality store will check it for free. Im lucky enough to have at least 5 parts store in a 3 mile radius from my house so I take it to 2 different stores to see if the results are differnet. especially if they tell me its a bad alternator and the whole thing needs replaced. Once I learned how to rebuild a alternator I have never replaced one. normally replace the brushes while I have it opened if they show signs of wear. Most of the issues Ive seen with them are cheap to replace.

IF you decide to go that route and it needs work let me know and I can walk you through it..

 

[Jimbos76cj]

Oh.. Forgot to add if it was a bad ground or broken wire I dont think it would jump to 16 volts.

 

[Hedgehog]

Okay - don't check the ground, what a silly notion that was for me to suggest......

 

[TN farmer]

I think it was a bad regulator, after putting a new alternator on everything is back working correctly. Thanks for the help.

 

[Jimbos76cj]

Okay - don't check the ground, what a silly notion that was for me to suggest......

I think it was a bad regulator, after putting a new alternator on everything is back working correctly. Thanks for the help.

 

[Hedgehog]

Well yeah a new alternator frequently will fix a world of electrical problems. It was my mistake in believing that the alternator was already checked for function. Glad your back on the road. I do believe that a poor or failing ground will cause unexpected problems through out the electrical system.

 

[Jimbos76cj]

Grounds are always the first thing I tell any one who has a electrical issue to double check every ground they can find.. Only thing that says bad alternator was the 16volts.. An alternator with a good reg shouldn't put out more then 14.6 volts. A bad ground in a alternator would cause the regulator not to click on and leave it producing less then that.