Denso style alternator ?'s

[hunt2elk]

Looking for some advice from anyone who has converted their alt over to the Denso style and measured the voltage output afterwards. Trying to understand if things are normal or out of whack. Put this setup on my car on Sunday. I have one of my good Fluke meters along side an Autometer volt meter in the cab to verify #'s. The car had been sitting for a couple of weeks. Started it up and it was charging at 14.3 initially. After driving about 5 miles it dropped down and settled right at 14 and stayed there for the remainder of the drive, about 20 miles. Perfect, I thought. Tonight I jump in for another trip. Went to a hardware store about 12 miles away. Started out at 14v and slowly dropped to 12.3v. Varying engine speed didn't change anything. Was in the store for 5 minutes. Started it back up to come home. Now it is putting out 13.68 - 13.8, which is perfect imo. So aren't these things supposed to be fairly stable and consistent, or will the output vary like what I am experiencing?

 

[tonysrt]

That 12.3 is a voltage from battery and not the alternator charging. Normally voltage with everything working OK is 13-14 volts, depending on battery charge. I have an autometer voltage meter and the Denso Alt. and I don't think the autometer is that accurate. I usually check voltage with digital VOM when in doubt. Make sure you have a good ground on the alt. or it could be a defective one. Double check all connections, I know it's basic, but cheap enough to check again. Also make sure the ignition switch is always energizing the field, could be defective ign. switch or feed to the alt..

 

[hunt2elk]

I am positive the alternator is grounded good. For the 12v switched wire, I removed the guts from a stock style 69 and older electronic voltage regulator and tied the 2 terminals together. Then used the original green wire that went to the alt for my power. Ran another wire back to the starter relay for "sense". I replaced the ignition switch earlier in the year with an older nosr usa version. I'll double check all connections again tomorrow.

 

[hunt2elk]

That 12.3 is a voltage from battery and not the alternator charging. Normally voltage with everything working OK is 13-14 volts, depending on battery charge. I have an autometer voltage meter and the Denso Alt. and I don't think the autometer is that accurate. I usually check voltage with digital VOM when in doubt. Make sure you have a good ground on the alt. or it could be a defective one. Double check all connections, I know it's basic, but cheap enough to check again. Also make sure the ignition switch is always energizing the field, could be defective ign. switch or feed to the alt..

So does your voltage output vary from 13-14 depending on rpm's and ambient temperature?

 

[threewood]

How old is the battery? If the battery is fully charged the alternator should slow its charging. When battery is low it will charge at a higher rate. Seems plausible. Did you run a wire from sense straight to the battery? It detects battery volts to vary charging rate.

 

[hunt2elk]

How old is the battery? If the battery is fully charged the alternator should slow its charging. When battery is low it will charge at a higher rate. Seems plausible. Did you run a wire from sense straight to the battery? It detects battery volts to vary charging rate.

Battery is only 1-2 years old. I ran the sense wire to the starter relay main stud with a fusible link, which is also where the #8 alternator charge wire is. The MAD bypass deal.

 

[threewood]

My blue wire goes direct to battery.
My green wire goes to the bypassed vr
The bolt on alt wire goes to my starter relay via fusible link.

 

[451Mopar]

I use one of these Transpo HD regulator units with adjustable voltage:
ADJUSTABLE EXTERNAL VOLTAGE REGULATOR KIT FITS CHRYSLER DODGE PLYMOUTH, 1970-87 | eBay

 

[hunt2elk]

Well, in case anyone is wondering, apparently I had a defective alternator. No surprise there with the way my luck goes on these old cars. Went and bought another alt, swapped it in without touching anything else and it charges at a steady 14.1v.

 

[threewood]

Well ain't that some crappy deal.

 

[Plumcrazy]

Best upgrade I ever did. Bought it from Mancini's.
I have to idle with the heater blower on high with the lights on high beam to move the amp gauge only slightly into the discharge side.