Voltage Regulator Adjustment

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Apr 29, 2005 | 06:53 AM

cw2

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Voltage Regulator Adjustment

I have a 49 f-1 that has been converted to 12 volt many years ago. All is fine except the other day I decided to put a volt meter on the battery and was suprised to find that it was putting out 14.9 volts. From what i have read it should be about 12.5-13.7 best I can tell and any extra could be hard on the new battery. I just installed. pulled the cover off the regulator hoping there would be an instruction decal on how to adjust but there was not. My question is how do I adjust to lower the voltage output??

Apr 29, 2005 | 09:24 AM

Earl

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From: Waynesville, OH

CW,

You may be thinking of the battery voltage when the engine is off. Here is a table of the voltage regulator settings at different regulator temperatures. I took it from a 1956 shop manual. Your regulator looks like it is in the proper operating range - depending on which generator you have. The instructions for adjusting the regulator are in the shop manual - a great investment if you don't already have one. Click the Parts Shop link in the upper left of your screen to get to MotorHaven, the on-line vendor that supports FTE. You should be able to find a shop manual for your truck there.

Apr 29, 2005 | 03:36 PM

51ford fan

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From: Seattle WA.

Earl, are those readings supposed to be taken at idle.

Apr 29, 2005 | 07:31 PM

oldfordtrucker

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CW2: my response is based on hearsay. I hope someone will respond with information based more on facts. My understanding is that the old batteries, like in the 50s and early 60s charged at a lower voltage. The newer batteries have a different composition lead and require a slightly higher voltage to charge properly. I have heard of people using old regulators with the new style batteries and having charging problems. If you have had the same set up for a long time and have had no problems, you may be suffering from "new information syndrome" (the 14.9 volts you just discovered). On the other hand, if you are boiling your battery or replacing it frequently, maybe you do need a lower voltage. I hope someone will either confirm or clarify the info I provided.

Apr 29, 2005 | 08:15 PM

cw2

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I still believe it is a little high though. At 1500rpm the volt meter reads 15.7 that almost 33% above the battery rating of 12v. I would appreciate if someone could could give me the procedure to reduce the volts and then I will adjust it from there.

Apr 29, 2005 | 09:02 PM

51ford fan

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From: Seattle WA.

Quote:

Originally Posted by cw2

My 51 alternator has about the same voltage readings as you are getting. I have been thinking that the new regulator might be the wrong one for the alternator. I bought my battery from Walmart a little over a year ago. When I'm driving to work in the morming and I turn on the heater the headlights blink. It makes me think the charging isn't all that high.

Apr 29, 2005 | 09:12 PM

Earl

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From: Waynesville, OH

CW,

Maybe someone can condense all the information you need to know to check out and adjust your regulator better than I can. Here is the page from the shop manual that talks about making the final regulator adjustments. There are several pages in the manual before this one that discuss tests you should run, and how the various regulator circuits work. You can try making only the voltage adjustment based on the page below, but you may need the other information to do the procedure properly and avoid changing the way the other parts of the circuit work. It's not just a matter of adjusting one screw to change the regulating voltage on these old girls.