Need Alternator Help

[rob]

I dont quite understand the issue , but my 2 cents is this. Remember the regulator regulates the voltage to the rotor. this is usually limited to about 14.5 volts on a normal alternator.The actual output of the alternator is 3 phase voltage passing through a diode rectifier. The rotor is provided current by the regulator that monitors output voltage. I dont quite see how it can be anything but a bad regulator. Im missing something I think

[rtpn60]

Nope.. I agree 100% Rob. However, there are only three wires to the regulator, Ground, Ign, Field. The ign powers up the regulator and then a field current is sent to the alternator to "excite" the alternator. However, I'm seeing the field voltage off the regulator go from 2.5v to 16v almost like a sine wave, not sure what's going on there?

Regards,

[rob]

ahhh Ill bet you have a bad diode allowing another phase vector to combine on the dc signal giving you a nice 17 volt ripple. there should be 3 diodes to invert the phase angle of the ac output to DC. Ill bet dollars to doughnuts thats the problem. One or more diodes are bad

[rtpn60]

That's what I would have thought too but the bench test is showing no issues? Also, If a diode were bad we'd see that on the output of the alternator (or ign on regulator) but instead am seeing it on the field output on the regulator? Something is just not adding up?

[gcyeaw]

Michael,
Have you tried a different meter for checking? Some DC meters don't react well to voltage with a lot of ripple (like from an alternator). I would be interested with what the output looks like when charging the batteries at the batteries.

[Bill Pape]

Bad gage or ground

[rtpn60]

I did go through the grounds at the batteries and the regulator. I removed the components and even filed off paint to get to the frame and added a ground wire from the regulator straight to the battery negative lead. I have another trip planned this Friday so I gave up and bought a Leese-NeVille 8LHA2070VE (110-555JHO) alternator that I'm installing today. Was able to pick it up for $170 and now be done with the remove regulator setup. I looked at serveral other alternators but most twice the price for only a few amps more so this seemed to be the best bang for buck.

[Bill Pape]

I do not have access to my old notes and paperwork, but your number seems to match 110-555JHO. I carry a spare reman found on ebay cheap.
170 is a fair price.

[iamflagman]

Originally Posted by rtpn60

I did go through the grounds at the batteries and the regulator. I removed the components and even filed off paint to get to the frame and added a ground wire from the regulator straight to the battery negative lead. I have another trip planned this Friday so I gave up and bought a Leese-NeVille 8LHA2070VE (110-555JHO) alternator that I'm installing today. Was able to pick it up for $170 and now be done with the remove regulator setup. I looked at serveral other alternators but most twice the price for only a few amps more so this seemed to be the best bang for buck.

Leese-NeVille 8LHA2070VE is what I use, check out;
http://www.prestolite.com/pgs_produc...esh=1229967332

[rtpn60]

I looked through the old posts to help find it. I did come across a 8LHA2057VA (110-450) also but really couldn't find a difference until I found some info that indicated the 110-555JHO could be turn in either direction. I thought that was a nice feature, especially for a spare that could be used on other vehicles too. FYI...