M1009 Battery overcharging

[Bairrfhionn82]

Just did the GP relay replacement and the Doghead relay on 12/18 test drove The Beast for a couple of miles no problem.Got in her yesturday to go to work 12 mile drive at about 6 mi mark I noticed gen 2 light on and the voltmeter pegged in the red,I quickly got off the highway.At idle it goes to high end of green and gen 2 light off and underpower gen 2 light comes on and the voltmeter goes straight to pegged in the red.I limped her home and disconnected the batteries when I touched both batteries they were just above air temp 30 degrees,no smoke, no burning smells and now the head lights don't work? They worked at the start of the drive, checked the fuses all good.I ordered the new relays for under the dash from CUCV Electric should arrive 12/23 also 2 weeks ago I replaced the driverside alternator with gm civie model. Any I thoughts ? Thanks.

 

[doghead]

I would use a voltmeter and measure each battery with the truck off, and running, and isolate your issue for sure.

Sounds like you have a bad regulator in gen2.

Have you ever rebuilt them?

 

[Bairrfhionn82]

Yeah last time I rebuilt one was around 1986. I haven't had a chance to test with a voltmeter yet will do tomorrow and order 2 rebuild kits from CUCV Electric. I'll rebuild the passside first and the old one I replaced last week will become my spare. Thanks Doghead for repying and for your MOD! I will update tomorrow or on the 24th.

 

[indy4x4fab]

May also have a bad battery. I know that sounds wrong but it happened to my wife's truck it started over charging the battery and I had the alt. checked it checked out better the it was suppose to and changed out the reg thinking it was that, still over charging. So I changed out the battery and everything started working fine. Never had a single issue starting the truck the hole time it was over charging but for what ever reason that battery must have had a bad cell that was causing the alt. to think it was almost dead. So check your batteries separately (make sure they are not connected when you start checking them, could lead to false readings).

 

[choll]

I had a battery issue last year on my 1028. They were new from auto zone, When I looked at them they were swollen and hot. brought them back to autozone the guy told me that they had gotten a bad batch. they replaced both and I havent had an issue since

 

[Bairrfhionn82]

Had the batteries checked 2 wks ago when gen 1 went south check good.I'll play with voltmeter tomorrow. Thanks for the replies.

 

[Bairrfhionn82]

Ok got voltmeter out and it wasn't working So went and bought a new one tested driveside alt keyoff 12.5v tested the passside keyoff 12.5v.Both batteries were retested at autozone and tested good 12.4v & 12.5v cca 950. driverside alt keyon 14.7v,passide key on 10.2v. Voltmeter in cab read high green to low red and when I goosed it, it would go into mid to high red.I also received CUCV Electric underdash relays and installed them today.Alt rebuild and glowplug realy coming soon.I removed the pass alt and checked the contacts and cleaned them up it spun freely no grinding sounds and put her back in stlill same issues oh well i'll just wait and rebuild both alts at once.. Happy Christmas to all ! or in Irish " Nollaig shona duit!"

 

[AlexFolino]

Your going to really like the relays and kit from CUCVelectric, very good stuff!

 

[Bairrfhionn82]

The relays are night and day different then the old ones better made are heavier by weight as well as quality. I just haven't run the Beast long enough to notice. That will be fixed when the rebuild kits get here.

 

[Bairrfhionn82]

Ok just received the rebuild kits from CUCV Electric when I get home from work @ 2340 hrs CST I will rebuild the old driverside first(it is already off) then I'll rebuild the pass side and install the new GP controller. I'll update tomorrow night after everything is done,crossed fingers and toes.

 

[Bairrfhionn82]

Ok I rebuilt both alternators great! Took the rebuilt drivers side and put on the pass side(had not rebuilt pass side yet.) Started her up and Gen 2 stayed lit So I rebuilt the pass side alt took the old drivers side alt off and put it back on the drivers side and Gen 1 light stayed on sooo,my guess old divers drivers side is shot? I took the alt from Autozone and put it on the drivers side both Gen lights came on and went out as they should but back to the overcharging issue So that alt is going back to Autozone in the AM.The volts on ds alt key off 13.5v key on Beast running 16.5v-17v,bat 2 25v and 25v at the alt.So thats it for now more tomorrow.

 

[Bairrfhionn82]

Ok just cracked opened the old d/s alt the only thing I found was one of the magnets broke just at the pinhole.Everything looks good,I'll have autozone test it when I bring theirs back.

 

[Bairrfhionn82]

Well finally it is fixed.Went to Autozone this A.M. and exchanged their bad alt with a new one they couldn't test the old D/S because their cord to the exicter was broken oh well.The new alt went in hooked the batts up turned the key both GEN lights came on nice and bright started right up light went out volt meter was right in the middle to 3/4 in the green backed it out of the garage and went on a 10 mile test drive.The needle never moved even with all lights on and heater on high. Now I can wire it for the Warn jumper cables.

 

[indy4x4fab]

Glad to hear you got her all fixed up.

 

[Bairrfhionn82]

Well my new AutoZone alternator is screaming when I put the headlights on, turn HL off no screaming,drive at highway speed turn HL on no problem voltmeter right where it should be.Stop at a light VM creeps down toward yellow hit the go pedal she starts screaming again shut HL off marker lights on screaming goes away.I am going to take the alt back to AutoZone have them test it and give me a new one again.No I do not have wires rubbing and all grounds were cleaned up when I had the alts out and when I replaced both HL.

 

[Bairrfhionn82]

Removed the alt today, real fun when it's 12* out and light snow.Took it to AutoZone tested bad well no sh#t.It smelled like cooked electric wires.I had them test the new one it tested good will install later today Sat morning start her up and slowly turn on my electronic doo- dads to put a load on the alt and see what happens. Update later!

 

[Bairrfhionn82]

Ok,new alt installed volts check fine,voltmeter right where she needs to be.I turned everything on one at a time til it reached max amp draw it moved just a tick,yahoo! Now the trick is will this alt last more than a week?

 

[Bairrfhionn82]

2 months + later everything works fine.With everything on including the 12v heater for the rear window no problems.Volt meter stays in the green and dosen't move.

 

[M1008driver]

The AutoZone alt you had so much trouble with. Was it the DL7157? Your story troubles me.

 

[Bairrfhionn82]

Yes it was. The AutoZone I use alt tester was out of commission so I brought it home anyway and ended up with 2 bad alts.When I brought the last one back the tester was working so I made sure that they tested my alt before I left the store.They had 2 on the shelf and 1 tested bad out of the box the good one has been working fine for the last 2 months. Make sure you have them test it before you leave that store.