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Author Topic: Alternator problems  (Read 3244 times)

March 20, 2017, 08:56:54 pm

Kwaiin

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Alternator problems
« on: March 20, 2017, 08:56:54 pm »
So I discovered through various tests that I had a bad alternator, so as anyone would do I ordered a new one. Well, a reman. Anyways I get it, bolt it up and connect the B+ to the battery as it should be. My blue wire for the exciter was cut at some point by the factory plug at the alternator (could someone fill me in on where I could find the other end?) Knowing that it will self excite at certain Rpms, I gave her a little throttle and all of a sudden the alternator starts SCREAMING. Not belt squeal but like screeching, the belt is not too tight, it's actually loose to factor that out.

Did I get a bad reman? Or am I doing something wrong?



Reply #1March 20, 2017, 09:56:30 pm

Kwaiin

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Re: Alternator problems
« Reply #1 on: March 20, 2017, 09:56:30 pm »
Further notes:

Alternator connected to battery then excited=12.5 V and screeching noise.

Alternator not connected to battery with car running, then excited= no screeching. With multimeter leads from alternator B+ to negative batt terminal, meter reads over 18 volts.

Bad voltage regulator? Alternator overworking itself?

Reply #2March 21, 2017, 03:43:02 am

vanbcguy

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Re: Alternator problems
« Reply #2 on: March 21, 2017, 03:43:02 am »
Are you sure it's not the belt slipping? If it isn't them the "new" alternator is toast.

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Reply #3March 21, 2017, 05:37:36 pm

Kwaiin

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Re: Alternator problems
« Reply #3 on: March 21, 2017, 05:37:36 pm »
Turns out it was a few things. The belt was tight, but I guess not tight enough. Also the "new" alternator pulley is just barely not spaced far enough away to line up properly with the belt. So while the belt was tight and everything spun as it should, it was the belt all along lol. I feel dumb but hey, it happens. Now I just need to make the pulleys align better and make a better tensioner bracket

Reply #4March 21, 2017, 05:43:54 pm

Kwaiin

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Re: Alternator problems
« Reply #4 on: March 21, 2017, 05:43:54 pm »
also, I have a 2 terminal connector by my battery not plugged into anything, with a blue and red wire. Is this blue wire the exciter wire? I can't find any other blue wires that aren't plugged into anything and I'd rather have that then have to rig something. Whoever had this car before me was quite the "wiring specialist" clearly..

Reply #5July 05, 2017, 12:13:02 pm

air-cooled or diesel

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Re: Alternator problems
« Reply #5 on: July 05, 2017, 12:13:02 pm »
1 you need your exciter wire hooked up(correctly, find the right wire, put a connector on it, hook it up, not difficult)(maybe you need to add a length of wire to it, as it may have been cut, can use a connector, or solder) with out the exciter wire i figure the current in the alternator is backing up, get it working correctly, dont run till you get red warning light on the dash to go out.
another these days we have to keep our pulleys, esp from the alt. if you have A/C its imperative, the reman or new alt they send you have some type of pulley on it, you have to swap in your old just used pulley. otherwise it may not line-up correctly. finding a pulley at a store can be impossible and a little expensive, that is IF you can find the correct pulley to fit. like $45 or so for a pulley you could have just pulled off old alt before you core it.

Reply #6July 06, 2017, 12:08:25 am

ORCoaster

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Re: Alternator problems
« Reply #6 on: July 06, 2017, 12:08:25 am »
Kwaiin,  I just spent the better part of two days fighting with an alternator so here is what I suggest.

To find the proper blue wire that is meant to excite the alternator get a jumper wire and insert one end in the blue wire and get the other end on a good ground.  This should turn the light on the dash on when you rotate the key to ignition.  Just check the two blue ones you have and use the one that lights the light. 

Red wires going to the alternator are 12 volts hot all the time.  So be careful on those.  They go to the battery and may or may not have a fuse link in line.  Like you say it was visited by a specialist.  You should have two red wires to the B+ terminal of the alternator and the D+ one is the blue wire spot.

I had the misfortune of having the wire break at the black plug and it was giving me on and off alternator performance.  Sometimes it charged and sometimes it didn't.  So I finally just cut the wire off at the plug.  Then I took a piece of stiff wire about an inch and a half long and put a sharp point on it and using needle nosed pliers I inserted it about 3/4 of an inch.  Then I took the blue wire and stripped a bit off and presoldered it.  I slipped on some shrink tube over the wire and proceeded to solder the blue wire to the inserted stinger.  Once it joined I brought down the shrink wrap and warmed it up and voila!  I now have positive contact to the alternator and it charges just fine at 14.2 or so. 

I learned in the process that voltage regulators can go bad as they are cheaply made overseas.  When an alternator is working it is putting out about 18 volts and that amount of juice will fry your battery and a bunch of other electrical parts.  So that is why they regulate it down to 13.6 to 14 VDC.  Sounds like you have all the reason in the world to return the alternator to the place of purchase.  Hopefully not on line.  I hate paying for return shipping .

Hope this helps. 

 

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