Amp Gauge bouncing

[slamons]

I have replaced Insturment voltage seloniod, and voltage regulator. Whats the next step.....

[MotorDog]

If you are having the amp gauge needle bouncing back and forth, replace the voltage regulator for the alternator. Make sure the belts are tight and the alternator mounting bolts are tight. The old point type voltage regulator is famous for acting this way. I highly recommend you get a new "electronic" one. There is only a couple of dollars difference in price. Some places no longer sell the old point type regulator.

I'm assuming you have replaced the little tin can voltage supply on the back of the cluster. You also say you replaced the voltage regulator. I'm thinking you have already replaced the voltage regulator for the alternator. If that is what you have done, then I would take the truck to AutoZone, Crager, Schucks, or someone like that and have them test your alternator and regulator. They will do that for free. I think you're still going to find the voltage regulator is the problem....even if new. You can get a "bad" new part, also. Good Luck and let us know what you find.

[slamons]

OK I have tried 3 new voltage regulators, All cause head lights, interior lights and gauge to surge, the guage jumps from the middle then pegs at charging...The alt is new, I did have to remove the Wiring incasement on back of the alt wiring harness. I did have a wire break in middle of the plastic / rubber moulded wiring grommet that attached to the alternator....Does any one have any other ideas?

[knightfire83]

I had the same problem years ago before my 4g alt. conversion. My problem was in the wiring between the alt. and regulator. Untape it all and check for bad connections, broken, crossed, shorted wires or terminals.

[slamons]

Thanks, I found something but not sure whats missing.....I have found a yellow wire out of the regulator up to the battery silonid. In the middle it was spliced to a red wire, in the same place where a relay or something else was on the large black wire running from the alternator.....When I disconnected the yellow from the red the problem stopped....What is missing ?????

[slamons]

Help, I found what I need on another truck, Can any one tell me if it is a fusable link or a resistor....The wiring between the Alt and battery seloniod, has the large black wire In the black wire is what appears to be a fusable link, also running into this fusable link is a yellow wire, This wire comes out as a red wire. This is what I am missing. can any one tell me what I need to replace this and get my voltage gauge working?

[fordman]

that is a connector is all it is. what year is your truck i cant remember.

[knightfire83]

Help, I found what I need on another truck, Can any one tell me if it is a fusable link or a resistor....The wiring between the Alt and battery seloniod, has the large black wire In the black wire is what appears to be a fusable link, also running into this fusable link is a yellow wire, This wire comes out as a red wire. This is what I am missing. can any one tell me what I need to replace this and get my voltage gauge working?

It had been 3 years since I messed with this and your description brings it all back. I was replacing the wire to the alternator from the battery side of the solenoid. I thought that black mass on the large wire was just a connection point where the red and yellow wires joined the larger wire.

So when replacing the large wire I just spliced the red and yellow into the big wire and this is when my alt gauge and lights were doing exactly what your is doing. So I cut open the large black mass on the wire I replaced to see what was inside and there was nothing there, besides a connection between red and yellow. The red / yellow wire has no connection to the bigger (batt.) wire.

The fix was to remove the red and yellow wires from the large wire leading to the solenoid (battery). I connected red to yellow directly and things all worked like they should.

Your ALT gauge in normal operation on these trucks barely move at all if any. It'd be a good investment to install a voltmeter if you really want to know whats going on in your electrical system.

Maybe this will help?