12 volts at idle

[joesipper]

hey fellas, i'm having a charging system issue in my 72 (with a 302). of course it all started with a dead battery. currently i have a new optima red top, new voltage regulator, rebuilt alternator, a new alternator wiring harness, and really clean grounds. i confirmed the original harness had a short in it and am convinced that was the initial problem, but now when the system is tested i have only 12 volts at the battery and am told i should have 13 to 14. my question to anyone with an answer is: should i be concerned about this? do i still have a problem? will i be straining the battery? Thanks for any input, by the way, my idle is set at 700 give or take.

kevin

 

[Seabronc]

I'd try another regulator. It should be putting out about 13.5 volts. depending on the pulley size on your alternator, you should be getting 1400+ RPM on the alternator. That is plenty fast enough to have it put out properly.

Good luck,

>-

 

[joesipper]

thanks for the advice fred. believe it or not, i haven't yet tried another regulator, but i'll get to it. the good news is my battery hasn't died! i do have some fresh questions. some carb related, some shifter related. as a newbie, could you inform me to the best way to go about this. i'm sure my questions have been discussed, but is there an easy way to get quick answers.

 

[Crude dude]

Are you sure your alternator is even charging? Check voltage with engine off and then running. If it only jumps up a little with engine running rev engine up a little and see if voltage jumps up or if your head lights get brighter. Most alternators are built crappy anymore and that could be the problem but like Seabronc said it would most likely be the regulator. Its very easy to upgrade to an internally regulated alternator. I have done this on both of my Broncos and love it. Much cleaner under the hood. Before you spend anymore money you should look into this conversion. Good luck

 

[Seabronc]

thanks for the advice fred. believe it or not, i haven't yet tried another regulator, but i'll get to it. the good news is my battery hasn't died! i do have some fresh questions. some carb related, some shifter related. as a newbie, could you inform me to the best way to go about this. i'm sure my questions have been discussed, but is there an easy way to get quick answers.

I can probably help with the carb, but not too sure about the shifter. That is what is great about a forum, you usually can find someone here that has had the experience or similar one to yours to help you get pointed in the right direction.

As far as the alternator, is concerned Crude Dude is right on. It is hard to beat the 3G alternator. It has been the premier alternator for Ford for a long time, even after they started using 4G and up. The upgrade is almost a no brainer, all you have to find is a 3G and the harness that goes with. You can find them in junk yards or buy a new one, the only thing you need to know is which one will fit your truck as there are several mounting options.

Quick answers are as fast as someone on the forum sees your post and thinks they have something to contribute. I try to read the new posts on a daily basis, but there are times I don't get to look at them for two or more days. It will also help you if you start a new thread for each question. When they are attached to an old thread they can easily get overlooked.

Good luck,

>-

 

[Orangecrush]

Not sure if it's fixed yet. I had a similar problem; and, it drove me nuts. It turned out to be so simple. It was a belt that was slipping. It wasn't squealing; so, I didn't even realize it.

First, just make sure the belt is tight. My problem went further due to the fact that the belt didn't contact the alt. pulley on enough surface. So, even though it was tight, it was still slipping. Here's a test: run the engine for 5 few minutes or so. Then, drip a few drops of water the on the alternator pulley. If it boils off, it's a slipping belt, as that will heat up the pulley like crazy.

 

[joesipper]

thanks for all the ideas fellas. so far i've tried another regulator and got the same results... undercharging at idle. i even called tom's bronco parts to see if the pulleys included in my power steering kit are underdriven. the answer was no. lonnie seemed to think it was in the alternator. i'll try the belt trick and if that doesn't settle anything, i'll resort to taking the alternator off again and have it thoroughly inspected. the alternator does charge, but not until 1000 rpm. how many amps are recommended for a 72 with a.c. and a winch? thanks all.

kevin