Electrical Problems @ 17.5 VOLTS!? regulator woes? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**passthebuck** · 04-26-2004, 08:02 PM

I'm trying to install an electrical Autometer temp gauge in my truck. It was used but I wired it all up & no go - I thought it was bad. I sent it back to atometer & they replaced it n/c. I installed the new one & it moved a bit & stopped. I have it protected by a 3amp fuse but I tested the voltage & the meter read 17.58 volts when the engine was running! Whats going on here? has my voltage regulator gone south? Is the regulator that box on the inside core support? What should I be doing/looking for? I'd like to get this figured out before I have to pay Autometer to fix this gauge... Thanx for your advice!

JimKshortstep4x4 · 04-26-2004, 08:20 PM

That is a very high voltage reading. It should be around 14.5 volts at the battery. I would check three things to start with.

-Make sure the regulator on the radiator support is properly grounded

-Verify reading with another meter, just to make sure

-If reading is still high, adjust or replace regulator

An option is to replace the alternator with an internal regulator style alternator.

Jim

**passthebuck** · 04-26-2004, 11:15 PM

ttt

cdowns · 04-26-2004, 11:35 PM

give the regulator a sharp rap on the side with a small hammer alot of times the contacts are stuck and doing this will free them up if it goes back to normal 12-14volts your set but if it happens again replace the reg

Jimmy72custom · 04-26-2004, 11:55 PM

I had a regulator go out on a 67 Camaro. It was before dawn I turned on the headlights and headed down the road. All of a sudden the lights got brighter and brighter the faster I went, I could really see well. Then total darkness, burned out both headlights. Weird

**passthebuck** · 04-27-2004, 09:54 PM

ttt

**passthebuck** · 04-27-2004, 11:39 PM

ok - so I changed the voltage regulator & I'm getting 16.1 volts at the battery. Is that too much still? It droped like a volt & a half from 17.58! What is too much? Should I worry about it?

cableguy0 · 04-27-2004, 11:53 PM

thats still too high it shouldnt be any higher than 14.5 your going to cook your electrical system along with a good change of having the battery boil and explode

**passthebuck** · 04-28-2004, 12:01 AM

so what is my next step?

grayw0lf · 04-28-2004, 12:46 AM

It sounds like you do not have a decent multimeter & are relying upon dash gauges for accurate voltage readings when troubleshooting.

I would think that the first thing to do would be to go to most anywhere & buy a decent multimeter. Auto parts stores should have them. Radio Shack always has good ones for a somewhat fair price. They will also be able to help you pick a good one & give you a quick how-to.

John

**passthebuck** · 04-28-2004, 10:24 AM

But I am using a multimeter.....

Jimmy72custom · 04-28-2004, 12:04 PM

16 volt is high, I have seen a charging system run that high for a short time with a very low battery. Put a full charge on the battery with a charger. Then test the volts with your tester at the battery with the truck running. If it is still 16v there is a problem.

Jeepster376 · 04-28-2004, 12:27 PM

I believe 14.5 should be measured at the alternator, and 13.8 should be measured at the battery while charging. The over charging can boil the acid out of the battery and cause serious corrosion in the engine compartment.

DennyB · 04-28-2004, 01:13 PM

If your alt is still pushing 16V then your battery should be charged if not overcharged.
Whats the volts at the battery with the engine off?
If its under 12 then you probably have a dead cell in the battery.
This is an odd one.
The regulator should have corrected the problem.
I have also seen new regulators that were bad.
Do you know any one with a known good regulator you can try to rule out that possibility?

When my regulator went in my 71 it pegged my amp meter, by the time I got it in the driveway the battery was swollen and oozing out acid.
That was a close one

Denny

cdowns · 04-28-2004, 01:29 PM

i'd try a different multi-meter,or at least compare the one you're using to a different one. some of the less expensive ones are not at all accurate

70short · 04-28-2004, 01:48 PM

Put the meter across the Battery with the engine shutdown or you can put the meter on some other truck/car and see what it reads you could also go to A local autoparts store and They will have A multimeter they can put on your system to confirm the integrity of your meter. I had A bad meter that read approx 18V at my bat. It was A craftsman they replaced the meter. Instead of screwing around with the external regulator $. Buy A internally regulated alternator easy install and be done with it.

Gary

**passthebuck** · 04-28-2004, 07:15 PM

I'm thinking that i'll change to an internally regulated alternator soon, I just wanted to make sure I'm fixing the problem & not just stabbing blindly. I like MAD electrical's kit too. I THINK that since I just changed the regulator & I'm still putting out too many volts that my ground somewhere is bad. I'm going to check it tomorow. I'll kepp ya posted

**passthebuck** · 05-03-2004, 10:29 PM

it was a bad ground too. Now i'm at 14.3V. thanx to all for your help.

04-26-2004, 08:02 PM	#1
passthebuck Sisyphus was my mentor! Join Date: Sep 2002 Location: Carleton Place, Ontario CANADA Posts: 984	Electrical Problems @ 17.5 VOLTS!? regulator woes? I'm trying to install an electrical Autometer temp gauge in my truck. It was used but I wired it all up & no go - I thought it was bad. I sent it back to atometer & they replaced it n/c. I installed the new one & it moved a bit & stopped. I have it protected by a 3amp fuse but I tested the voltage & the meter read 17.58 volts when the engine was running! Whats going on here? has my voltage regulator gone south? Is the regulator that box on the inside core support? What should I be doing/looking for? I'd like to get this figured out before I have to pay Autometer to fix this gauge... Thanx for your advice! __________________ passthebuck #5642 -TWO 1967 GMC 910's. One with L6/3-on-the tree and the other with 355 w/435hp & a 700r4. -a 2013 Honda Civic as my "sensible" car

04-26-2004, 11:15 PM	#3
passthebuck Sisyphus was my mentor! Join Date: Sep 2002 Location: Carleton Place, Ontario CANADA Posts: 984	ttt __________________ passthebuck #5642 -TWO 1967 GMC 910's. One with L6/3-on-the tree and the other with 355 w/435hp & a 700r4. -a 2013 Honda Civic as my "sensible" car

04-26-2004, 11:35 PM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	give the regulator a sharp rap on the side with a small hammer alot of times the contacts are stuck and doing this will free them up if it goes back to normal 12-14volts your set but if it happens again replace the reg __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

04-27-2004, 09:54 PM	#6
passthebuck Sisyphus was my mentor! Join Date: Sep 2002 Location: Carleton Place, Ontario CANADA Posts: 984	ttt __________________ passthebuck #5642 -TWO 1967 GMC 910's. One with L6/3-on-the tree and the other with 355 w/435hp & a 700r4. -a 2013 Honda Civic as my "sensible" car

04-27-2004, 11:39 PM	#7
passthebuck Sisyphus was my mentor! Join Date: Sep 2002 Location: Carleton Place, Ontario CANADA Posts: 984	ok - so I changed the voltage regulator & I'm getting 16.1 volts at the battery. Is that too much still? It droped like a volt & a half from 17.58! What is too much? Should I worry about it? __________________ passthebuck #5642 -TWO 1967 GMC 910's. One with L6/3-on-the tree and the other with 355 w/435hp & a 700r4. -a 2013 Honda Civic as my "sensible" car

04-26-2004, 08:20 PM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	That is a very high voltage reading. It should be around 14.5 volts at the battery. I would check three things to start with. -Make sure the regulator on the radiator support is properly grounded -Verify reading with another meter, just to make sure -If reading is still high, adjust or replace regulator An option is to replace the alternator with an internal regulator style alternator. Jim

04-26-2004, 11:55 PM	#5
Jimmy72custom Registered User Join Date: Apr 2004 Location: Willits Ca Posts: 261	I had a regulator go out on a 67 Camaro. It was before dawn I turned on the headlights and headed down the road. All of a sudden the lights got brighter and brighter the faster I went, I could really see well. Then total darkness, burned out both headlights. Weird

04-27-2004, 11:53 PM	#8
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,948	thats still too high it shouldnt be any higher than 14.5 your going to cook your electrical system along with a good change of having the battery boil and explode __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

04-28-2004, 12:01 AM	#9
passthebuck Sisyphus was my mentor! Join Date: Sep 2002 Location: Carleton Place, Ontario CANADA Posts: 984	so what is my next step? __________________ passthebuck #5642 -TWO 1967 GMC 910's. One with L6/3-on-the tree and the other with 355 w/435hp & a 700r4. -a 2013 Honda Civic as my "sensible" car

04-28-2004, 12:46 AM	#10
grayw0lf Registered User Join Date: Apr 2004 Location: Clanton, AL Posts: 1,253	It sounds like you do not have a decent multimeter & are relying upon dash gauges for accurate voltage readings when troubleshooting. I would think that the first thing to do would be to go to most anywhere & buy a decent multimeter. Auto parts stores should have them. Radio Shack always has good ones for a somewhat fair price. They will also be able to help you pick a good one & give you a quick how-to. John __________________ 85' CUCV M1009!!! The newest addition! 6.2diesel, Th400, NP208, & only 36k miles! 70' C-10 LWB Fleetside - Looking good these days! 05' Dodge Neon 88' Winner Escape Sport 1750 - 4.3v6 94' Seadoo SP 84' Honda TRX200, bare nekkid. Just a frame & tires. Always looking for another project or any good deal!

04-28-2004, 10:24 AM	#11
passthebuck Sisyphus was my mentor! Join Date: Sep 2002 Location: Carleton Place, Ontario CANADA Posts: 984	But I am using a multimeter..... __________________ passthebuck #5642 -TWO 1967 GMC 910's. One with L6/3-on-the tree and the other with 355 w/435hp & a 700r4. -a 2013 Honda Civic as my "sensible" car

04-28-2004, 12:04 PM	#12
Jimmy72custom Registered User Join Date: Apr 2004 Location: Willits Ca Posts: 261	16 volt is high, I have seen a charging system run that high for a short time with a very low battery. Put a full charge on the battery with a charger. Then test the volts with your tester at the battery with the truck running. If it is still 16v there is a problem.

04-28-2004, 12:27 PM	#13
Jeepster376 Registered User Join Date: Feb 2004 Location: Massachusetts Posts: 269	I believe 14.5 should be measured at the alternator, and 13.8 should be measured at the battery while charging. The over charging can boil the acid out of the battery and cause serious corrosion in the engine compartment. __________________ 72 Cheyenne Super 4x4 SWB

04-28-2004, 01:13 PM	#14
DennyB Led Sled! Discs R 4 ME! Join Date: Jan 2001 Location: Toms River, NJ, USA (Transplanted Hoosier) Posts: 7,327	If your alt is still pushing 16V then your battery should be charged if not overcharged. Whats the volts at the battery with the engine off? If its under 12 then you probably have a dead cell in the battery. This is an odd one. The regulator should have corrected the problem. I have also seen new regulators that were bad. Do you know any one with a known good regulator you can try to rule out that possibility? When my regulator went in my 71 it pegged my amp meter, by the time I got it in the driveway the battery was swollen and oozing out acid. That was a close one Denny

04-28-2004, 01:29 PM	#15
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	i'd try a different multi-meter,or at least compare the one you're using to a different one. some of the less expensive ones are not at all accurate __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY



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04-28-2004, 01:48 PM	#16
70short Registered User Join Date: Sep 2003 Location: Boise ID Posts: 609	Put the meter across the Battery with the engine shutdown or you can put the meter on some other truck/car and see what it reads you could also go to A local autoparts store and They will have A multimeter they can put on your system to confirm the integrity of your meter. I had A bad meter that read approx 18V at my bat. It was A craftsman they replaced the meter. Instead of screwing around with the external regulator $. Buy A internally regulated alternator easy install and be done with it. Gary __________________ "72" Red CORVETTE 4-speed 350 "70" Chevy Short Bed early stages of resto. Edel 600 cfm carb Weiand Stealth Intake HEI shorty Headers 4/2 Drop 295 50R 15 TOYO on 10 inch wide corvette rally rims at all 4 corners. "CHEVY RULES" Last edited by 70short; 04-28-2004 at 03:49 PM.

04-28-2004, 07:15 PM	#17
passthebuck Sisyphus was my mentor! Join Date: Sep 2002 Location: Carleton Place, Ontario CANADA Posts: 984	I'm thinking that i'll change to an internally regulated alternator soon, I just wanted to make sure I'm fixing the problem & not just stabbing blindly. I like MAD electrical's kit too. I THINK that since I just changed the regulator & I'm still putting out too many volts that my ground somewhere is bad. I'm going to check it tomorow. I'll kepp ya posted __________________ passthebuck #5642 -TWO 1967 GMC 910's. One with L6/3-on-the tree and the other with 355 w/435hp & a 700r4. -a 2013 Honda Civic as my "sensible" car

05-03-2004, 10:29 PM	#18
passthebuck Sisyphus was my mentor! Join Date: Sep 2002 Location: Carleton Place, Ontario CANADA Posts: 984	it was a bad ground too. Now i'm at 14.3V. thanx to all for your help. __________________ passthebuck #5642 -TWO 1967 GMC 910's. One with L6/3-on-the tree and the other with 355 w/435hp & a 700r4. -a 2013 Honda Civic as my "sensible" car

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