Alternator charging too much..

rattlecanpaint

rattlecanpaint

Well-Known Member
Joined
Apr 18, 2005
Location
Winston Salem
So I've put two different alternators in this thing, a new voltage regulator and rewired the voltage regulator to alternator.

Original alternator died, when the B+ wire broke. I figured that was also the cause of my flickering charge and e brake warning lights. I fixed that and the lights were still on so I put in the first new alternator on in. Lights still on and charging too much voltage. (Got up to about 17 before I could shut it down). Put a new voltage regulator on it but same thing. Ran new wires from voltage regulator to alt, lights go out but now it doesn't charge at all. Put in second alternator, stil not charging. (but the lights are out.) When I put a meter across the battery terminals with the engine running I get 12.5 volts and dropping. Drops faster when I rev it up. Any ideas?
 
I had a similar problem on an old Chevy truck. but I actually BLEW all my lights out before i could shut it down. I then replaced all my lights and got a new alternator, didnt show a charge, so I got another one and it did work. I took the first replacement back to the parts house and they tested it for me and found that it was a defective "new" alternator, so you cant always trust a new alternator is going to be a good one. Take yours to advance or somewhere like that and hav them test it. IF your good on the alternator try looking at fusible links to see if maybe you fried one, thus not letting the system draw power from the alternaor....just a thought. Good luck
 
I took the first one back to advance and they tested it and said it was good. I made them give me my money back and got one from Carquest. I'm at a loss here. I checked the b+ wire off the back of the alternator and it's got 12 volts going to it with the engine off so I figued it was OK.
 
Bad ground maybe. Alot of the time when you have an electical problem that makes no sense its a bad ground.
 
I've checked every ground I can find. I'm at a complete loss here. None of it makes sense. Unless the second alternator is bad...which would be just my luck.
 
Went to Advance Auto to get an alternator for an old Dodge cube van we used as a racecar hauler.

It took 4 trips, 5 alts....the 1st 4 checked bad when we went back.
They checked 2 in the store....one of those was bad. We took the good one.


Matt
 
The first one I took back tested good on their machine, but I was still a bit leary so I made them give me my money back and I got one from carquest. Intersting thing they were different and the one from advance was the wrong one to begin with. the plugs were only slightly different but I figured that could have been the problem. I still don't know what the damn problem is with this thing.:kaioken:
 
Try adding a ground from the alt. bracket to the battery.. at least 8 gauge for a 75 amp alternator, 4 gauge up to ~150.
 
Are you thinking the grounding through the bracket to the engine is compromised? It's definately something I'll try tomarrow. I'm getting desparate.
 
I've seen problems like this before. Rember this, ground to 12v. Ohm out your ground(s), it is possible that the wire is broken or not making good connection in the center. Have you load tested the battery? :rolleyes:
 
snappy said:
I've seen problems like this before. Rember this, ground to 12v. Ohm out your ground(s), it is possible that the wire is broken or not making good connection in the center. Have you load tested the battery? :rolleyes:
Click to expand...
The battery is a 2 month old Optima yellow top and it has done well. I've driven it from Harrison/Reedy creek to my house almost in wake forest, then today I had to drive it back there and back to the house just on the battery. I've charged it up a couple of times, but even after a half hour drive in traffic/highway it will still start the engine right up. No slow crank or anything. But, no I haven't load tested it with a tester. I'll check my ground wires. Thanks for the replies, keep em coming!:beer:
 
Are you using something reliable to measure the voltage? I only mention it because when I bought my buggy it came with an inexpensive sunpro gauge that reported 9 volts. I measured it with a multimeter and it was fine, about 13.7 volts. So I bought a new gauge and installed it. The new gauge (also a cheap sunpro so it matched the others) tells me it's 16 or 17 volts. I measured it with two different multimeters and they confirmed that it's actually working fine at about 13.7 volts. Now I just mentally subtract a few volts and use the gauge as a rough guideline.

So, it couldn't be that you're measuring it with something unreliable could it?
 
Nope, using a fluke multimeter. I've now put a second voltage regulator on it and ran a ground wire directly to the batt. Still nothing. I'm thinking of running a hot wire directly to the battery also and then another one from there to the back of the alt to get it started. I'm so pissed off at this thing I could just drive it into a tree as fast as it will go!:uzi::uzi:
 
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