Archived Quivering amp gauge

[4everm14]

My 1991 D-250 Amp gauge has started to vibrate at idle. The lights change intensity in time with this amp gauge flutter. New Alternator and Voltage regulator show no change. I fear the system may fail and I'll be stranded. Any ideas.

D. W.

 

[Bugman]

I'm no expert. Could be a number of things, I'm sure otherTDR members will help you out on. Things I might check for,



Is there any interference on AM radio? Mine did when a diode was bad on the alternator.



Maybe the vibration at a bad connection?



Good luck,

 

[Paychk]

What is your location? Has it turned cold yet? The volt meter and headlights will fluctuate in time with the intake heater cycling. This is normal after a few minutes, depending on the outside temperature, it will quite.

 

[B.G. Smith]

Sounds like the regulator, it is part of the PCM on later year model trucks. It is part of the computer control on my 89 Ramcharger. bg

 

[4everm14]

Thanx for the replies.

I am aware of the heater grid amp draw. In my situation the amp needle looks as if it's nervous. Very different from the hard and distinct draw of the intake heater. My other first gen truck displayed similar traits before she flatlined. ----------- no electrical from the dash forward. I still don't have a solution for that either.

 

[RonWeiss]

Sounds like a bad diode in the alternator.



Ron W.

 

[4everm14]

I agree that the symptoms say regulator or alternator. I replaced both but still have flutter in the lights. I guess it is possible that the rebuilt replacement is defective. It is also intermitant so it is difficult sometimes to duplicate the symptoms. Thanx for the replies and suggestions, Diesel guys are the best.



David

 

[Shovelhead]

Also check, clean and resecure the grounds to the body and engine.