Voltage gauge or altenator problem!

[GSchneuer]

Today my Check Gauges light came on with 0 volts on the gauge. After shutting down the engine & restarting, the light stays out for a while with the gauge showing a little over 12 volts. Battery voltage is 12. 35 on both, but with engine running I only get 0. 64 vdc off of the fuseable link wire at the Altenator and at the wire eyelet at the battery. Truck has 49,000 on the clock. I really think the Altenator has 1 or 2 bad diodes, its a 135 amp.

Does anybody have any idea's as to what is wrong?, all help is appreciated.



Thanks, Gary

 

[LesStallings]

Are your batteries original?

 

[kruisecontrol]

check the power from the battery and compare it to the nut behind the alternator, engine off , if no power on the back of alternator u have a blown fuse or fuselink normally iirc 140 amp, if you do have the same power , check for codes & inspect the battery sensor below your left battery truck should read 13-16 volts @1800 rpms ,if all ok send the alt for testing at autozone or similar and start shopping for one.