Voltage regulator/ alternator issue 1986 8v92 #106

Voltage regulator/ alternator issue 1986 8v92 #106 - Printable Version

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Voltage regulator/ alternator issue 1986 8v92 #106 - [email protected] - 01-05-2026

Maybe I can get recommendations or insight on my issue before I do unnecessary testing and removal.
I left Austin tx and drove 5 hours on my way to Scottsdale Az and everything was running great.
Pulled over for the night in Sonora Tx. The next morning we were continuing on our journey for about 30 min on I-10 aprox 75 mph and noticed the dash amp meter was really jumping to 100 amps and back and forth to 0 amps . First thought was the gauge but then I saw the volt meter start jumping also from 12 to 16 volts and staying at 16 volt for a bit then jump back down . At this point I new something was serious . Rode another 5 miles for a safe place to pull over . Upon inspection saw or heard nothing odd.
I pulled one cable from the alternator circuit braker located in engine compartment taped it off and continued on the way for 12 hours with just power from house and engine battery power with no problem.
Sounds like the voltage regulator located on the alternator ? Was getting ready to pull the gear driven alt but thought I might ask for insight.
So seem like alt is working but putting out 2 much.
Should I look anywhere else beside regulator?
Pull just Regulator on Alt or pull Alt as a unit?
Can I test Diode trio while Alt is installed or Just assume it is regulator the way gauges are jumping and pegging maximum .
Any recommendations on source for parts service, I'm still in Scottsdale for a little longer.

Alt info below looks like original from1984 miles on coach under 100k 1986 dd8v92 40'

LEECE-NEVILLE division SHELEER-GLOBE corp
date8441 volt14 amp130
service parts#3725JC complete unit model A0013725JC

Regulator LEECE NEVILLE regulator 99500 14 volt
each House battery tested 13.08v
each Engine battery tested 12.89

Thanks in advance Jeff

RE: Voltage regulator/ alternator issue 1986 8v92 #106 - Jack Houpe - 01-06-2026

I understand your underway but the best thing to do is remove it and have it tested. I would inspect all the terminals and connections for loose or corrosion issues. Glad you have good batteries those voltages are perfect.

RE: Voltage regulator/ alternator issue 1986 8v92 #106 - [email protected] - 01-06-2026

(01-06-2026, 05:03 AM)Jack Houpe Wrote: I understand your underway but the best thing to do is remove it and have it tested. I would inspect all the terminals and connections for loose or corrosion issues. Glad you have good batteries those voltages are perfect.

Great advice thx!
Was in a bit of a hurry to get here and help a family member who has now past.
I will get in there in inspect wiring and grounds.
I see a local rebuilder to maybe test it ( Turbo and Electric in Phoenix) if it comes to that.
If I can find a source for the regulator I was thinking I would try anyways since existing is 40 years old and probably not adjustable.
Jeff

RE: Voltage regulator/ alternator issue 1986 8v92 #106 - Tf175 - 01-06-2026

What Jack said . Poor ground can cause similar issues . Is your alternator direct drive mounted above bell housing ?

RE: Voltage regulator/ alternator issue 1986 8v92 #106 - pairodice - 01-07-2026

You can probably get the testing procedure from the mfg

RE: Voltage regulator/ alternator issue 1986 8v92 #106 - Richard - 01-07-2026

https://www.qualitypowerauto.com/Penntex%20Alternator%20and%20Regulator%20Test.pdf

I know you don't have a Penn Tex, but this procedure will allow you to test without extracting the alternator.

RE: Voltage regulator/ alternator issue 1986 8v92 #106 - [email protected] - 01-07-2026

Chris, yes, the alternator is mounted over the bell housing. Looks like our coaches are 16 apart in production that year.

I crawled up in the engine compartment and looking at things . Decided, I'm probably going to pull the alternator so I can get a better look and try to do more testing. While I have it out I will clean the grounds and the connections and wires.

Richard
I would like to test it in place with the cables hooked up with Ignition on then off and then running but so far, I only see 3 wires. So not sure I can do the simple test .
One wire is the large double 00 ground. One is large double 00 power cable. And the other is a small red cable coming off the regulator looking like it's going forward, thinking, maybe tachometer.
Maybe that's my problem that I'm only seeing 3 wires. I know I had an issue with a raccoon in the engine compartment one time last month messing with a mouse trap.

Adrian
Yes probably get specific year model etc info from Newell factory next , also maybe the source of a new regulator ?

thank you all for your thoughts
Jeff Helser

RE: Voltage regulator/ alternator issue 1986 8v92 #106 - [email protected] - 01-07-2026

RE: Voltage regulator/ alternator issue 1986 8v92 #106 - Richard - 01-08-2026

I dont know about your generator but newell had a method of wiring the alternator in later coach that baffled me becuase it did not use all the wites that were supposed to be connected. i suspect the small red wire is the excite wire.

I worked on a 6V tach on Chockwolds coach. it was a separate sender not from the alternator