Hey guys ,any one ever have there alt. gauge bounce?
If I put my turn signal on it will shoot over to high charge just for a sec. or pull the light switch ,or step on the brake ,or at idle in gear. any time a power drain is put on it it even at high RPM it will spike just for a split second. I have put in 2 new volt regs. last one is a mopar unit. and just installed a new alt. and pulled the grounds and cleaned them .new battery too.
Its never done this until about a month ago am I missing a ground some were? is this a ground issue?
Thanks R

 

funny stuff, mine just started this about a month ago also. ive tried a new reg. too and was thinking about a new alt but if it didnt fix yours maybe ill hold off for moment. is your check eng. light on? mine is, and its a code 41 which is a generator/alternator field fault... im not sure where to go from here. i hope you can figure yours out so maybe it will work for mine. good lucky!

 

Is the ground on your volt reg good? Mine wouldn't charge at all because of a bad ground one time then another it wouldn't quit charging and I would take the volt reg off and make sure it was grounding to the firewall and it fixed it, I haven't had a problem with it in a few years now.

 

If it has a separate voltage regulator, it will bounce a bit when lights are turned on. The PCM based regulator does not typically bounce at all. I switched to a Mopar external one and got the bounce. Switched back to the PCM and it was normal. Probably doesn't help at all, but information is good, right?

 

Main body ground on the core support good? Might want to check voltage drop through it with headlights on and heater fan on high.

Try running a ground wire from the regulator case to the engine.

 

it still has the factory bat. ground cable on it and it looks good .maybe its bad at the bat. post. I will try the ground from reg to eng. any idea what gauge wire
to run #10 or #8 or ?
like I said its never done this until a month ago .and the only thing diff. was a new rebuilt trans and I cant see how that relates

 

16 gauge would be plenty for the VR ground. The field does not use much current.

 

You might try adding a second heavy gauge ground wire from the engine to the body.

When I reworked my relay harness for my headlamps to take power from the alternator hot terminal & ground back to the engine I also tied the 10GA ground wire to a couple bolts on the radiator bulkhead. This cured the bouncing volt meter on my truck as a side effect of the upgrade.

 

great, I will try it out tomorrow and get back to post results

 

Ok still acting up,I put a new ground from battery to core ( Used a large #4 copper ) no change. then I added 1 from the VR to the engine also (#10) no change . I also used a multimeter and its charging at 14.32 to 14.60 and constantly going up /down .is that normal? like I said its never done this ever. also i noticed it that at times it will shake constantly a 1/4" at times in gear at idle then stop and be rock solid then for no apparent reason start shaking again.
Did I get a bad alt? or is it the reg. or something else?

 

mine is doing the EXACT same thing. i hope sombody has a solution. is your check engine light on?

 

no I dont have one

 

Just does it at idle, right?

 

no some times it will shake like crazy going down the road . it will bounce real hard if put in reverse or the turn signals on sometimes its real steady other times it looks like a sawsall blade moving I have tuned power of to a/c heat.
what I did see is, if i drain the battery and put a heavy charge on it its stable

 

I know a lot of things have been mentioned, but the intermittent occurance points to a grounding issue, flakey diodes in the alternator, even a slipping belt. I would try bypassing the light switch and running hot wires from the battery to the light. If it goes away you know it's not the alternator or battery. If it stays the same, maybe misbehaving alternator.