battery problems - voltage regulator?

bigwaylon

bigwaylon

Well-Known Member
Joined
Mar 22, 2005
Location
Charlotte
yeah, this could go in Tow Rigs, but it's really a general electrical problem...

rented the dually out this past weekend to a 4-wheeler in need...

I had put dual batteries in it about 8 months ago...and have towed to Crozet, Gulches, Uwharrie, etc, and never had a problem...

brief summary of the story I got (hopefully those involved can help fill in the gaps)...

trip was from ~Hickory to somewhere in TN on Thursday...climbed all the hills just fine, but somewhere just before the destination, they smelled something funky (like sulfur) and popped the hood...noticed one of the batteries was swollen up and had popped one of the covers off and spilled out a bit...

since the truck only came with one battery, it was decided (wisely) that there should be no problem driving it back home with just one...

got almost back home on Sunday evening....truck died, and they checked and battery number two was toast...these were brand new Interstate Mega-Tron Plus batteries...

one bad...I'd buy that...two bad, and maybe a bad batch? but they put the red top from the Jeep into the Dodge and get it home...then try to crank it Monday morning to bring it back to me and it just goes click-click-click...

story is the output of the alternator was 14.1V or so, and didn't seem to be a problem...

it doesn't sound like the alternator has died...rather it sounds as if it's overcharging the batteries?

a couple of the guys up there wheeling said they'd had similar problems, and it was the voltage regulator being held wide open...this also caused the batteries to die overnight...

anybody else agree? anybody have any other ideas?

the '89 CTD doesn't have much under the hood to fool with, so there aren't many options...not sure if it's right or not, but AutoZone does show a voltage regulator for an '89 D350 with the diesel (part number VR733...$14.99), so it wouldn't be too tough of an attempt at a repair...

guess I gotta see about the warranties on the batteries, too...cause they're toast...

Thanks.
Greg
 
A hung voltage regulator could easily overcharge a batt, especially if you have a hot rod alternator.

Have someone check voltage output while you hold the engine around 1800 rpm.

It should be 14-16 max at full charge, if it was putting down 14 at idle, well Id be nervous.
 
Yup, hung voltage regulator is what I'm thinking too.
 
SkyHiK5 said:
A hung voltage regulator could easily overcharge a batt, especially if you have a hot rod alternator.
Have someone check voltage output while you hold the engine around 1800 rpm.
It should be 14-16 max at full charge, if it was putting down 14 at idle, well Id be nervous.
Click to expand...


I know they said they checked the voltage...not sure if it was at idle, or not...

Hopefully Chris, or Dave, or somebody else that was there can confirm...


I'll try the voltage regulator first...any idea where it's gonna be? I guess it has to be inline between the battery and alternator somewhere?

Greg
 
once I replace the batteries and the voltage regulator...is the way to test it just use a voltmeter on the battery terminals to see what they're reading at different RPM's?

Greg
 
i think the voltage regulator is on the firewall. that will deff cause the problems your seeing. once you get the regulator youll recognize where its at (its a metal box)... just put a voltmeter across the terminals while its running and watch the readings at idle and upto around 2k, should be 12.5-15 at all times.
 
paradisePWoffrd said:
i think the voltage regulator is on the firewall. that will deff cause the problems your seeing. once you get the regulator youll recognize where its at (its a metal box)... just put a voltmeter across the terminals while its running and watch the readings at idle and upto around 2k, should be 12.5-15 at all times.
Click to expand...


thanks...

and the dual batteries won't make a difference, as that just adds amperage, not voltage, right?

Greg
 
bigwaylon said:
I know they said they checked the voltage...not sure if it was at idle, or not...
Hopefully Chris, or Dave, or somebody else that was there can confirm...
I'll try the voltage regulator first...any idea where it's gonna be? I guess it has to be inline between the battery and alternator somewhere?
Greg
Click to expand...
Just found the thread, i had been looking in the tow rig section for it:confused:.
You have the facts right, but we did only check the voltage at idle, i think it was 14.4v.

Dual batteries would keep this from happening, if anything. Spreading the output of the Alternator between 2 batteries would make it less likely to hurt them.
 
uglyjeepoffroad said:
Just found the thread, i had been looking in the tow rig section for it:confused:.
You have the facts right, but we did only check the voltage at idle, i think it was 14.4v.
Dual batteries would keep this from happening, if anything. Spreading the output of the Alternator between 2 batteries would make it less likely to hurt them.
Click to expand...

I found the single battery I took out last year when I converted it to dual...

I'm going to hook it up (might have to charge it first) and check voltage at higher RPM's...then I can check it again after changing the regulator...

Greg
 
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