I need to adjust my voltage regulator. I am showing 15.5 volts while driving. One battery has already been roasted by the previous owner. I found the adjustment procedure in one of my manuals. However, all of the numbers are for a 6 volt system. My question is what is the cut-in voltage (6 volt = 6.4-7.0)? What is the Charging voltage (6 volt = 7.1-7.4)? The book lists the amps for the 6 volt system as 31-33 amps. I'm sure mine would be different because the F-7's had a bigger generator.

This is on a 1948 F-7 which is converted to 12 volt. The voltage regulator looks stock with three coils under the cover. I am using a 12 volt generator.

John
NNY

 

John, p 378 in the shop manual shows 40 amps for the 8EL-10002-B generator.

It also shows cut in voltage of 6.0 - 6.6 and voltage regulation of 7.2 - 7.6 with amp regulation of 38-42 for regulator 8L-10505.

It's been my experience - I'm weak on theory - that changing to 12V increases the voltage output by only 6. I'd set cut in at 12.0-12.6 and regulation to 13.2-13.6.

Hope this helps.....

 

John, I looked up the voltage table in a 1957 Ford car manual for 12 volt system. Should get you a ballpark figure. The regulator compensates for temp changes, so to check it on the vehicle the engine should be at normal operating temp and you should use a thermometer to determine the temp on or near the regulator with the engine running so the cooling fan will stabilize the temp. The cover must be on the regulator.

The table goes from 25 to 145 degrees, so if we say your temp is 85 then the regulation setting would be 14.5 to 15.3 for the Standard regulator, 14.1 to 14.8 for 40 amp Autolite. The higher the temp the lower the setting to prevent over charging. At 35 degrees the voltage should be 15.0 to 15.8 for Standard and 14.3 to 15.2 for Autolite 40 amp.

Since you are having over charging, the regulator contacts may be stuck or burned. Best to replace the regulator.

Hope this helps.

 

could you switch to an alternator and get a new voltage regulator?

 

John,

Basically, you would double the voltage and halve the current from the 6V specs. In general, you would expect 14.8-15.2 with 12V stuff. 15.5 is a little high, but it should not cause serious overcharging. Many meters are inaccurate at this voltage range, so I would suspect with serious overcharging, that the voltage is higher, above 16V. Normally you only have to check cut-in, almost never have to adjust it. The idea with cut-in is that the generator is disconnected at idle, and when it spins up higher it will cut in at 750 rpm or so. The third coil is for high current cutout and it almost never would have to be adjusted. If you don't have a meter that is calibrated, borrow one that is. If you set the voltage below 14.6, you won't get a full charge. A battery that is at rest will read about 13.8V after being charged, or about 12.8V after an hour.