Need Help Guys

[JCart]

New Optima Batteries last month.
200 amp Leece-Neville alternator.

Here is the question:

Start the truck this afternoon and alternator looks like it's de-charging on the gauge like the glow plugs are on (so just touching the low side of the "N"). But never comes up in 20 minutes of idle and running around town for fuel. Usually comes up after G-plugs cycle.

Get out the meter and it shows 11 volts when truck is running at alternator and batteries.... shut engine off and shows 12 volts whats goin on?

Had a check engine light the other day when firing it up that stayed on and went off after a bit. CEL does not seem to come on when I first turn the key on fire up. I do have a stancor glow plug relay could this be sticking or something.....

any suggestions would be awesome as I have to get to work with it tomorrow at 4:00 AM......

Thanks jrc

 

[jschildm]

You could see if the glow plug relay is sticking on with volt meter or test light. I believe the relay stays on for 2 minutes (ish...). After ample time to kick off, if both large posts on the relay are hot then it is stuck on. I would doubt this is the case though, because I think one post is hot all the time, so I would have thought it would run your battery dead just sitting there.

 

[JCart]

so I unhooked both large posts on the GP (Stancor) relay.... still shows discharge...

Not sure what else to do... thinking I should start pulling fuses while engine is running to see if alternator gauge returns to normal when I pull them individually?

jrc

 

[Patrick Feeley]

Just went through this with my alternator. Mine was doing the same thing although it would come up to normal occasionally, but then go back down. I took the alternator off and removed the voltage regulator. One of the armature copper tracks that the brushes ride on was messed up (spots of copper missing ... just rough looking). A rebuilt alternator and everything is normal again. You may want to inspect yours. Cheers!

 

[7.3psd97444]

Its prolly not the Stancor. They are probobly the best relay out there. Never heard any issues with them. Check altenator conections and wires. Sometimes the main connector on top will break or wiggle loose. Mine did and caused charging and lighting issues.

 

[LA_Stroker]

There's always the Chevy test too. After the GPR cycles out tap the Alt. housing a couple times with something metal (light hammer or a ratchet) to see if the charging comes back. If it does then the brushes have either swollen or worn past where the brush springs can hold them tight against the armature.

 

[JCart]

Thanks guys put on a spare stock alternator and system is charging. Need to get the Leece neville looked at when I am next home.
Thanks for your suggestions