voltage regulator - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jjk3 · 12-06-2003, 11:35 PM

I figured I might as well post this here also. I'm trying to figure out why my my alternator is overcharging the battery. I put a new voltage regulator in about 4 months ago, but it didn't help. When I hook my voltmeter up to the battery terminals and tach the engine up to about 2k, it reads over 16 volts. I know this is way too high, and will damage the battery. I'm just trying to figure out what's causing it. Thanks for any help. Here's a link to the other post. John.

http://67-72chevytrucks.com/vboard/s...836#post626836

walker · 12-06-2003, 11:40 PM

Might put in another voltage regulator. The new tiawanese ones are notorious for being bad. Also remove all your ground terminals and sand till you see bare metal. That seems to cure alot of mysterious problems.

**old Rusty C10** · 12-06-2003, 11:48 PM

yeah grounds can do all kinds of wierd crap

chevymad · 12-07-2003, 12:17 AM

I switched to internal regulated alternators several years ago, just because i couldnt get a voltage regulator to last more than 6 months anymore. The quality on most of them nowdays is terrible.

I'm not sure which wire is which, but i believe one of the wires on the regulator should be a voltage sensing wire. If theres resistance in that wire it wont get a true reading of the system voltage. It'll read lower voltage, making the regulator think the truck needs more volts. This resistance can also be on the ground side as others have said. I'd be checking the voltages and grounds if you plan on staying with the external regulator. If you dont want to hassle with it, just get a 1 wire alternator. Most parts stores have em, theyll bolt right in place of your old one, and all you have to hook up is the main post on the back.

12-06-2003, 11:35 PM	#1
jjk3 It's just a check engine lamp. Join Date: Apr 2001 Location: Melbourne, FL Posts: 311	voltage regulator I figured I might as well post this here also. I'm trying to figure out why my my alternator is overcharging the battery. I put a new voltage regulator in about 4 months ago, but it didn't help. When I hook my voltmeter up to the battery terminals and tach the engine up to about 2k, it reads over 16 volts. I know this is way too high, and will damage the battery. I'm just trying to figure out what's causing it. Thanks for any help. Here's a link to the other post. John. http://67-72chevytrucks.com/vboard/s...836#post626836 __________________ Active Inliner---bigchevy66 68 SWB Stepside 250 L6/3 on the floor/ Hedman headers, HEI, MSD 6A box, K&N filter, Offy intake and Edelbrock 600cfm 4 barrel Soon to have: WC T-5 five speed 66 SWB Stepside-undergoing restoration

12-06-2003, 11:40 PM	#2
walker Registered User Join Date: Jul 2003 Location: north of Phx AZ about 30 miles Posts: 698	Might put in another voltage regulator. The new tiawanese ones are notorious for being bad. Also remove all your ground terminals and sand till you see bare metal. That seems to cure alot of mysterious problems. __________________ Andy,Phx AZ '67 C-10 (Ahhh, done at last. Well there is that disk front end I want to put in and...) "23 C-Cab-sold '48 Ford 8N tractor(still working) '67 Scout(Now on the road) '70 MG B.-sold

12-06-2003, 11:48 PM	#3
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,313	yeah grounds can do all kinds of wierd crap __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

12-07-2003, 12:17 AM	#4
chevymad Registered User Join Date: Jan 2001 Location: skamokawa, WA, USA Posts: 527	I switched to internal regulated alternators several years ago, just because i couldnt get a voltage regulator to last more than 6 months anymore. The quality on most of them nowdays is terrible. I'm not sure which wire is which, but i believe one of the wires on the regulator should be a voltage sensing wire. If theres resistance in that wire it wont get a true reading of the system voltage. It'll read lower voltage, making the regulator think the truck needs more volts. This resistance can also be on the ground side as others have said. I'd be checking the voltages and grounds if you plan on staying with the external regulator. If you dont want to hassle with it, just get a 1 wire alternator. Most parts stores have em, theyll bolt right in place of your old one, and all you have to hook up is the main post on the back.



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