Voltmeter real jumpy...lights flicker....idle jumpy..?
03-19-2002, 08:36 PM
#1
Racer
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Voltmeter real jumpy...lights flicker....idle jumpy..?
Volt gauge gets real jumpy sometimes dancing between 10-14 volts, could this be a bad voltage regulator or an alternator going bad? 
Also just noticed headlights and dashlights flickering when volt gauge did "the dance". Idle and overall running seemed a bit unstable, ironic or could it be......bad alternator <img src="graemlins/crying.gif" border="0" alt="[crying]" /> <img src="graemlins/crying.gif" border="0" alt="[crying]" /> <img src="graemlins/c.gif" border="0" alt="[ouch]" />
Also just noticed headlights and dashlights flickering when volt gauge did "the dance". Idle and overall running seemed a bit unstable, ironic or could it be......bad alternator <img src="graemlins/crying.gif" border="0" alt="[crying]" /> <img src="graemlins/crying.gif" border="0" alt="[crying]" /> <img src="graemlins/c.gif" border="0" alt="[ouch]" />
03-19-2002, 10:54 PM
#2
Three Wheelin'
Fletch,
When my idle gets too low or won't hold, (cold start problem, clears within 10-15 seconds) I get the same kind of symptoms. I attibute it all to low idle and not an electrical problem. I see it as the electrical "dropping off" because of the low (practily stalling) idle.
I would lean towards looking at the reason the idle drops before chasing alternator / regulator problems provided that if you rev the engine up to about 1500 rpm or so, the problem clears. Does it?
Greg
When my idle gets too low or won't hold, (cold start problem, clears within 10-15 seconds) I get the same kind of symptoms. I attibute it all to low idle and not an electrical problem. I see it as the electrical "dropping off" because of the low (practily stalling) idle.
I would lean towards looking at the reason the idle drops before chasing alternator / regulator problems provided that if you rev the engine up to about 1500 rpm or so, the problem clears. Does it?
Greg
03-20-2002, 12:16 AM
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You know...when I start my '85, all the lights on the instrument panel stay on until I rev the engine above 1800 rpm. I've had several Volkswagens that also do this.....anyone know why? How to stop it?
Normy~
Normy~
03-20-2002, 10:11 AM
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Normy, FWIW, although 15-1800 rpm seems low, it's not uncommon for the alternator to not excite the field (and thus reach output) until a good rev is given. Usually, you need to kick it up to about 3K - the disease has afflicted a few list members in recent memory.
Dunno if that's what's happening here, but my shark will occasionally fail to start charging, and it runs like crap until you give it the good rev.
My backyard diagnosis (and posts from Wally and Snowball) has shown the following to be suspect:
1. The alternator excites through a resistor in the back of the instrument panel. Bad resistor or connection can do this.
2. I've had luck clearing the problem temporarily by cleaning up the contacts on the alternator itself - if my B+ post (blue wire) gets grungy, I'll have the problem.
Fletch, do a search of the post archives for posts by Steve Cattaneo on grounding and alternator checks - he lays it out well.
Dunno if that's what's happening here, but my shark will occasionally fail to start charging, and it runs like crap until you give it the good rev.
My backyard diagnosis (and posts from Wally and Snowball) has shown the following to be suspect:
1. The alternator excites through a resistor in the back of the instrument panel. Bad resistor or connection can do this.
2. I've had luck clearing the problem temporarily by cleaning up the contacts on the alternator itself - if my B+ post (blue wire) gets grungy, I'll have the problem.
Fletch, do a search of the post archives for posts by Steve Cattaneo on grounding and alternator checks - he lays it out well.
03-20-2002, 03:56 PM
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Racer
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Condition stays even when revved above 1800. It just started wigging this bad. Needle was stable at 13.8 most all the time. Lights never flickered before either.Will have to get tested. Seems like the voltage regulator is going bad to me.
Can you replace just the regulator and if so where is it located?
Can you replace just the regulator and if so where is it located?
03-20-2002, 04:17 PM
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Yes, regulator alone can be replaced. You'll have to drop the alternator to do it.
Might want to get the alternator itself tested before doing it to rule out bad brushes, etc.
VRs are ~$80. Reman alternators can be had for around $100.00.
VR is #2 on the picture.
(Hope I'm not flagrantly flauting copyright laws)
Might want to get the alternator itself tested before doing it to rule out bad brushes, etc.
VRs are ~$80. Reman alternators can be had for around $100.00.
VR is #2 on the picture.
(Hope I'm not flagrantly flauting copyright laws)
03-20-2002, 06:20 PM
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Test the battery output with the car running/not running. If you get a higher reading with the car turned off; it's probably the alternator.
This happenned to me (very suddenly and without warning).
This happenned to me (very suddenly and without warning).
