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I've been pulling my hair out (what's left of it), trying to diagnose a problem where my sub-woofer cuts in and out without warning or pattern.
1969 Coupe.
Happens only when driving. All is fine when engine is off and it's running only off the battery.
It's one of those Rockford-Fosgate compact subs (PS-8) that I have mounted to the back wall of my rear compartment and wired directly to the battery.
Just today, on a nice Friday drive into work, I noticed that the sub cutting out seems to be linked to when my Volt meter jumps up to about 18V (I changed from a broken Amp meter last year). When the voltage comes back down to 15V or lower, the sub comes back on. Pretty consistent relationship, once I put my finger on it.
The Alternator was new 3 years ago last month (it was the first thing I ever replaced on my Vette - the day after I brought it home!).
Should I suspect the Alternator is on the Fritz? I'll likely remove it and take in to O'Reilly's tonight to have them test it.
Thoughts?
Could be the sense wire is loose or has a break in it.
+1, the sense wire receives a voltage signal from the rest of the system.........if this is an internal reg alt, and it tests ok, start there....I had this problem last year with an 82' C20......it would fluctuate voltage and bury the gauge. Redoing the sense wire fixed it. I suggest hitting up the forum here for a wiring schematic. There is a thread here where the guy will send you any year you want......or get one like I did from Dr.Rebuild.
Thanks, I'll check that connection first.
I actually had a dead/dying battery earlier this summer due to the whole Alt harness connector popping loose from the Alt.
Maybe the sense wire alone is not making contact. The Volt meter seems to fluctuate too much on the high side, and that seems to be what the Sub is disagreeing with.
Thanks for the help.
Problem solved!
It was the alternator connector at the sensor wire that was loose.
If i wiggled it, the volt meter would go wonky and hit 18V at the aame time the sub would cut out [evidently had a self protect breaker].
Got an off the shelf connector pig tail at O'Reilly and got that all buttoned up.
Works like a charm now.
No voltage spikes, and the sub is happlily thumping away!
Thanks!
Voltage Too High: Alternator?
