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Electrical Problem - Sudden Voltage Drop

Electrical Problem - Sudden Voltage Drop

cglax6

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Vehicle(s)
'76 CJ5, 351w, Ford T18/D20, D44 (open), D30 (open), 2.5" BDS spring lift, 31x10.5x15 tires
Took my visiting family for a drive around town in the CJ5 a couple days ago, and about 2 minutes into it, I glanced over to the dash to check speed and I saw my voltmeter drop from about 13.9V to ~12V. Stayed that way since...with headlights on and off...and even after shutting down and restarting.

I had an issue with low voltage since I bought it last year, and after chasing just about every wire, I noticed that it had a ground wire from the battery to the block, but not the block to the frame. I put a ground wire from the block to the frame and it solved my low voltage problem.

I haven't had the chance to check anything out because of work and crowded house with family, but I'll have a chance this weekend. Any thoughts of where I should go first...besides checking that ground connection again?

Voltage stayed about the same with headlights on or off. When the turn signal was on, it would drop pretty good with each blink. I'm sure there's a ground issue with the blinkers (it has a fairly fresh paint job and I'm sure those lights are grounded to painted metal), but I still only get 12V without them on.

I know electrical issues are the bane of our existence on these things, but I was just tossing this one out there to see if anyone had similar issues and/or a good place to start.
Thank you!
 
Have your altenator test'd for amperage output, as well as voltage.
Also-Run a dedicated GND from the dash panel to the battery NEG(-).
Move that one main battery GND to the top bolt of your starter motor.
90%+ of CJ electrical issues come from bad GNDs.
LG
 
I'm an idiot...should have checked under the hood sooner...

What's wrong with this picture????

IMG_20180803_170839.webp
 
Unless my eyesight is wrong, looks like your alternator belt is missing. FWIW, our voltmeter bounces a little with the turn signals on. We have a new high output alternator, all new grounds in the engine bay, and a new belt on the alternator. And a dedicated ground to the cluster gauge and the voltmeter. So ours does that too, but I cannot find anything wrong.

Sent using Tapatalk
 
Yeah, the belt isn't supposed to be draped over the intake manifold...

When it broke, it wedged between the main pulley and the belts for the power steering, so those were warped. Went ahead and replaced all three.

Good to go now!

Always something...
 
:agree:

LG
 

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