MEP 803A Low AC Voltage and Alternator not charging.

[Ray70]

I am concerned because it worked one day and gone the next.
Almost everything in this world does this.... it works until one day it don't!
Kurt's VR will get you going again and not have the known reliability issues associated with the OEM VR.

 

[cbisson]

I am concerned because it worked one day and gone the next.
Almost everything in this world does this.... it works until one day it don't!
Kurt's VR will get you going again and not have the known reliability issues associated with the OEM VR.

I have one of Kurt's VRs in my parts stash for this very reason.

 

[pstansel74]

I think I will have to grab 1 myself

 

[Medic1]

Received and installed Kurt's VR and all is well there, quick shipping, great price and great instructions. Now on the DC charging issue. Voltage reading at the alternator is 23.88 same voltage at the slave terminal. DC amp gauge is slightly in the negative. I have pulled the alternator and am looking for somewhere local that can rebuild it. If someone has a good alternator to sell I would be interested in that as well.

 

[kloppk]

I see you only have 111 hours on it (if it's accurate)
1) Have you checked fuse FU1 to be sure it's good?
2) Have you verified that the Exciter terminal on the alternator is getting 24 volts when S1 in in Prime/Run?

Failures I've seen in the alternators are:
- Failure of diode(s) on the diode plates inside the alternator (fairly easy fix)
- Worn out brush's (easy fix)

 

[Ray70]

@Light in the Dark also has a contact for alternator rebuilding IIRC.

 

[Medic1]

I see you only have 111 hours on it (if it's accurate)
1) Have you checked fuse FU1 to be sure it's good?
2) Have you verified that the Exciter terminal on the alternator is getting 24 volts when S1 in in Prime/Run?

Failures I've seen in the alternators are:
- Failure of diode(s) on the diode plates inside the alternator (fairly easy fix)
- Worn out brush's (easy fix)

F1 fuse is good and had good voltage at the exciter terminal. At the alternator shop now the diodes are bad, do you have a source for them?

 

[kloppk]

Which model alternator do you have?
8EM3005CA or 8MR3005CA?

Per the TM...
8EM3005CA
101-206 ..SEMICONDUCTOR DEVIC 1
0142499T36 ..SEMICONDUCTOR DEVIC 1


8MR3005CA
101-193 ..DIODE,NEGATIVE 1
101-235 ..DIODE,POSITIVE 1
101-130 ..DIODE,TRIO 1


From a Prestolite parts matrix
8MR3005CA alternator

 

[Medic1]

Thank you for that he was able to find some by cross reference, repaired for $85. Will put on tomorrow and hopefully this one will be fixed

 

[Light in the Dark]

@Light in the Dark also has a contact for alternator rebuilding IIRC.

I have withdrawn my recommendation of this particular shop, not sure they are even in business any more. Had 3 rebuilt and put on the shelf, two tested bad still when I pulled them down to use them. Not happy.

I do not recommend anyone use Dave's Starter & Alternator out of Enfield, NH. They were a Prestolite listed rebuilder at the time, not sure if they still are. Too much time has passed since they were gone through, for me to lodge a complaint.

Stupid me expected quality work out of an authorized repair house.

 

[2Pbfeet]

I have withdrawn my recommendation of this particular shop, not sure they are even in business any more. Had 3 rebuilt and put on the shelf, two tested bad still when I pulled them down to use them. Not happy.

I do not recommend anyone use Dave's Starter & Alternator out of Enfield, NH. They were a Prestolite listed rebuilder at the time, not sure if they still are. Too much time has passed since they were gone through, for me to lodge a complaint.

Stupid me expected quality work out of an authorized repair house.

That's a bummer to put it mildly. Alternators aren't exactly rocket science devices.