overcharging batteries on 84 3b (1 Viewer)

Joined
Apr 25, 2007
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678
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S.CA - N.OC - Fullerton
 
 
I'm just getting this on the road. The batteries that were in it were gone and pretty old. I put a couple good batteries in and I thought everything was fine until I noticed the volt meter hitting up around 16.

I put a meter on it while off and it read 12.8

While running at speed it was 17,2

I know this is not good and is probably the reason the old batteries were dust.

I have to head south by tomorrow night at the latest. I bought a regular from Lordco but I know nothing about installing it.

I really need to get on the road. Any thoughts or ideas. Thanks in advance.
 
Joined
Jan 25, 2011
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45
Location
Norwood Co
Voltage regulator

Your voltage regulator is either part of the alternator or a seperate piece on the inner fender or firewall. In my 84 pickup it was on the drivers side inner fender and was simply a matter of removing the bolts that held it on the fender and then disconnecting it from the wiring harness(it had plug connectors on each end). Look for the part in your vehicle that matches the one you bought, then put the new one in it's place. It should be that simple. Unless you bought a Voltage regulator that does not match. Good luck and have fun.

Happy motoring
 
Joined
Apr 25, 2007
Messages
678
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S.CA - N.OC - Fullerton
 
 
problem solved..... .was a aux cig lighter adapter i ran from the bat... must have a small internal short.... took it off and works fine...
 
Last edited:

bj40green

Tssss, tssss
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Dec 13, 2010
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Atenas, Costa Rica
 
Sorry, but I don't see the connection between overcharging with 17,2 volts, buying a new VR and Problem solved it was the aux cig. lighter adapter.

Am I missing something?????:confused::confused::confused::confused::confused::confused::confused:

Rudi
 
Joined
Dec 14, 2005
Messages
1,439
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colorado
 
 
do a voltage drop, load test on battery

Check the voltage drop from negative terminal to frame and also to engine. Then voltage drop from positive to B+ on alternator. Load check battery and check water level. If okay, then replace the alternator.
 
Joined
Apr 25, 2007
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S.CA - N.OC - Fullerton
 
 
sorry... been on the road........ i thought the problem was solved.... when i disconnected the hard wire i had set up for an inverter it seemed to normalize the charging system. When I got on the road It started up immediately. We were set to go so I put an old battery in to beat up and have the other two on standby for starting. I have had no time to mess with it so far and am currently in Tumwater WA. I have the VR with me but no meter. I'm pretty helpless with electrical problems unless it's cleaning connections or replacing parts. There is no chance of finding an alternator here. Anyway I'll try to follow Haryv's advice if I can get my hands on a meter. For now should I try dropping the VR in? Thanx
 
Joined
Sep 3, 2007
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8,871
Location
New Zealand
 
 
The best place to measure your charging voltage is straight across your battery terminals.

In a 12V vehicle ....

Greater than 14.7V (with the engine running and therefore with charging operational) usually suggests the voltage regulator is shot.

If you have an external regulator (mounted on the firewall) then they are easy to change (and I recommend fitting a solid-state version) to see if it cures your problem.

Solid-state versions have no points or moving parts and tend to be more reliable in my experience. (All internal voltage regulators are solid-state as far as I know.)

A battery won't last long with "excess voltage" (like your meters suggest your experiencing) and other electrical components (eg. headlight bulbs) are likely to fail too (as a result of the excessive voltage).

A fully charged battery has around 13.6V so you should aim to see only voltages in the range of say ... 13.5 to 14.7 while your engine is running but only 12 to 13.6 with it stopped.

:beer:
 
Joined
Apr 25, 2007
Messages
678
Location
S.CA - N.OC - Fullerton
 
 
.i popped the VR in and the gauage reads fine now... .. thankx for all the input.... i drove from BC to Roseburg before i could take the time to mess with it...... the sacrafise battery lost some water but did it's job well.... it would have been smarter to search for instructions before i did it but i figured it out.....

this vehicle was only tested for a couple days before embarking on this trip BC to LA ..... (bj60 5spd) .... 3 people and a 5spd with TC/BH and 300 apx. lbs. or parts..... it's slow up hills but what do you expect, right?..... a clocked 20 mpg last run ....i've got cetane+/injector cleaner, new oil, air filter, etc so we'll se if that improves anything......



The best place to measure your charging voltage is straight across your battery terminals.

In a 12V vehicle ....

Greater than 14.7V (with the engine running and therefore with charging operational) usually suggests the voltage regulator is shot.

If you have an external regulator (mounted on the firewall) then they are easy to change (and I recommend fitting a solid-state version) to see if it cures your problem.

Solid-state versions have no points or moving parts and tend to be more reliable in my experience. (All internal voltage regulators are solid-state as far as I know.)

A battery won't last long with "excess voltage" (like your meters suggest your experiencing) and other electrical components (eg. headlight bulbs) are likely to fail too (as a result of the excessive voltage).

A fully charged battery has around 13.6V so you should aim to see only voltages in the range of say ... 13.5 to 14.7 while your engine is running but only 12 to 13.6 with it stopped.

:beer:
 
Joined
Apr 3, 2006
Messages
1,729
Location
Laurentians North of Montreal, QC
I agree that the regulator is most likely defective. The most important thing with over-voltage is lost water and excessive battery temperature. You don't want temperature to exceed 45C for too long, as it may warp the plates. Keep deionized water at hand and keep refilling the battery until the problem has been solved.

The internal regulator is a fairly standard ND item, if you look around (I don't have one handy around anymore, sorry, can't give you the part number).

Until you get a replacement, you can disconnect the power to the alternator field and install a temporary switch. That will allow you to operate the alternator in a full on full off fashion. Basically you can work it until voltage drops no lower than 11.6V at rest* (fully discharged), then run the alternator until voltage at rest is 12.8 (fully charged). These figures are for standard wet cell lead acid batteries.

Good luck!

* Resting voltage is measured at least 2 hours after engine has been shut down.
 
Joined
Apr 25, 2007
Messages
678
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S.CA - N.OC - Fullerton
 
 
that's a good trick (put a switch in). Is dionized and distilled the same thing?

I agree that the regulator is most likely defective. The most important thing with over-voltage is lost water and excessive battery temperature. You don't want temperature to exceed 45C for too long, as it may warp the plates. Keep deionized water at hand and keep refilling the battery until the problem has been solved.

The internal regulator is a fairly standard ND item, if you look around (I don't have one handy around anymore, sorry, can't give you the part number).

Until you get a replacement, you can disconnect the power to the alternator field and install a temporary switch. That will allow you to operate the alternator in a full on full off fashion. Basically you can work it until voltage drops no lower than 11.6V at rest* (fully discharged), then run the alternator until voltage at rest is 12.8 (fully charged). These figures are for standard wet cell lead acid batteries.

Good luck!

* Resting voltage is measured at least 2 hours after engine has been shut down.
 
Joined
Dec 14, 2005
Messages
1,439
Location
colorado
 
 
usally it is a regulator. If you can get your hands on a regulator, can replace it but, do the preliminary checks anyway. Good idea to find undiscovered problems such as voltage drops ect then, fix the real problem. Worst thing that can happen in this case, the electrolyte can boil out of the battery, cause battery swealing on the sides, Green fuzz copper oxide eating away at the cables from the escaped gasses and also a explosion hazard. "look at its side" if its swollen, battery is shot. Then replace the regulator.
 
Joined
Apr 25, 2007
Messages
678
Location
S.CA - N.OC - Fullerton
 
 
the regulator's been in for a few days.... everything is running fine.... in Malibu now.... cruised back roads from SLO to Ohai yesterday then Hwy 1 from Ventura..today . now in Malibu..... going to take PCH all the way to Laguna...... 75 F,,,, ckear and sunny! 20 mpg the whole way carrying an extra 800 lbs of parts in the back ...... anyone coming to socal look me up, anytime....
 

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