Charging problems...still

[hairpin151]

I'm needing advice from someone smarter than me.I've got a 53' M37 thats bone stock and I cannot seem to get the dang charging system to work.I've put a govt. rebuilt gen. on it and a solid atate reg. that looks great when you take the cover off and still seemingly no juice comming out of the reg. when its running.I have the military adapters to check the gen. and reg. and the gen. shows that its putting out its share when runnung but when I check at the starter post with a multimeter I'm showing just whats in the batts., 24 volts.When I turn on the lights and the heater the voltage predictably drops to 23 volts or so when running.I've also tried a decent looking mechanical reg. that looks ok when you take the cover off and still get the same thing.I'm at my witts end.Any help will be greatly appreciated.Thanks.

[MSeriesRebuild]

I'm needing advice from someone smarter than me.I've got a 53' M37 thats bone stock and I cannot seem to get the dang charging system to work.I've put a govt. rebuilt gen. on it and a solid atate reg. that looks great when you take the cover off and still seemingly no juice comming out of the reg. when its running.I have the military adapters to check the gen. and reg. and the gen. shows that its putting out its share when runnung but when I check at the starter post with a multimeter I'm showing just whats in the batts., 24 volts.When I turn on the lights and the heater the voltage predictably drops to 23 volts or so when running.I've also tried a decent looking mechanical reg. that looks ok when you take the cover off and still get the same thing.I'm at my witts end.Any help will be greatly appreciated.Thanks.

I would check the cables & the end terminations next. If you have checked each component individually from the others, it's about all it could be. One other option, are the ground straps in place on the regulator mounts? If it doesn't have a GOOD ground, it will not put out.

[gwalker]

Did the truck have a solid state reg. on it before, or the older larger mechanical type?

[hairpin151]

It had the mechanical reg. when I got it.It has the ground straps on the reg. mount,I will check and clean them.

[hairpin151]

Well gang I took apart the voltage reg. mount and thoroughly cleaned it up and sanded bare all the metal to metal contact points and reassembled and then started it and checked the voltage at the foot starter post and still 24 volts,whats in the batts.I guess that I could get another reg. and gen. and hope for the best or just say the hell with it and go to a single wire alt.I would like to keep the original look but I'm getting seriously frustrated with this.

[GregL]

Hey Hairpin, when you say the generator is putting out it share, does that mean around 30v or so at idle speed? It should be higher than just 24v at idle.

Also, according to the manual, you must cycle the regulator several times by increasing and decreasing engine speed before reading it's voltage output with the engine at the equivalent speed of 20mph.

If you want I can scan the troubleshooting pages for the generator and regulator from TM 9-8030, but it won't be until later tonight.

[MSeriesRebuild]

Hey Hairpin, when you say the generator is putting out it share, does that mean around 30v or so at idle speed? It should be higher than just 24v at idle.

Also, according to the manual, you must cycle the regulator several times by increasing and decreasing engine speed before reading it's voltage output with the engine at the equivalent speed of 20mph.

If you want I can scan the troubleshooting pages for the generator and regulator from TM 9-8030, but it won't be until later tonight.

It's typical to see a discharge at idle RPM. This is typical in any generator system. Alternator systems will charge at a much lower RPM. What I'm saying is it will be lower than 24 volts at idle, RPM will have to increase significantly to get on the charge side of center. Just notice when driving at night, when stopped at a stop light, etc, the lights dim noticably. After you get going again, all returns to normal. If a discharge condition at idle is an issue, go ahead & make the change to an alternator system, it's the only way to get away from the discharge at idle condition.

[MSeriesRebuild]

Well gang I took apart the voltage reg. mount and thoroughly cleaned it up and sanded bare all the metal to metal contact points and reassembled and then started it and checked the voltage at the foot starter post and still 24 volts,whats in the batts.I guess that I could get another reg. and gen. and hope for the best or just say the hell with it and go to a single wire alt.I would like to keep the original look but I'm getting seriously frustrated with this.

I would suggest you put an ammeter in your system as a test before giving up, it will provide a much easier to read test of what your system is actually doing. Sometimes the voltmeter is deceptive.