The Stovebolt Site Forums The Shop Area The Electrical Bay '69 Chev charging system

I have a charging system problem with my truck, it is a 69 chev with an external voltage regulator. First my alternator tested bad, so I replaced it. Then with still no charge I jumped the first three terminals on the regulator and I get a 14.5 volt charge. I replaced the reg and plugged it in and still no charge. Is it this regulator or something else. Can anyone let me know what the basic operation of the regulator is and what tests I can make with a volt/ohm meter to identfy my problem.
Thanks, Ranger

The regulator is just what it says it reguletes voltage out put from the alternator so you wont fry your battery and other electrical goodies.my personal opinion:junk the external regulator systm and instal a later model internal regulator alternator.it is easy to do and will save a lot of head aches down the road

There is no need to change to an internal regulated system. The system you have will do fine if everything is right.

It sounds to me like there may be an open wire between the alt and reg. Disconnect the wires and check each one for continuity. While the meter is on it wiggle the harness and see if the curcuit breaks. Replace wires as nescessary.

The later setup is far better and a lot less hassle when it quits charging you just replace the alternator.

I understand the internal regulated idea and would like that except during this time of year money is a hurdle and this is my snow plow truck and needs to be running yesterday. I just bought an alternator and they won't take it back because it has been hooked up. The open wire idea I need to pursue. I have power to terminal #3 which is from the battery, I have a 7.5 volt reading to the number 1 (field) terminal and the #4 terminal. If I jump 12v to #2 terminal I get the 13.5 up to 14.7 volts to the first three terminals.
Just sitting key off should the regulator have 12v to anything other than the battery feed, how about when the key is on or the truck is running.
Again I ask how does the regualtor work inside. Does the alternator charge all the time and when the battery is up to snuff the regualor breaks the contact to the battery and thus the battery stops getting a charge? Should I have power at the alternatorwhen the key is off (other than the battery hot feed) or the key is on. I get nothing at the two wire plug when the truck is running unless I jump the #3 and #2 terminals on the regulator. #4 wire (brown) goes to the engine harness connector and then feeds to the L/H parking/directional signal circut, should this be a hot wire to the regulator, those lights work but there is no power to the #4 terminal...... Should there be any other hot feeds to the regulator other than #3 constant, is there a hot wire feed to the reg when the key is on other than #3.
Don't get me wrong, I appreciate the ideas but snow is falling and I'm Christmas broke.

Correction I do have 7.5 volts to #4 which I stated earlier in the last post. This a corrected statement from the last line where I said I had no power to #4.

I dont have a scematic handy but one wire to the regulator should be hot when you turn on the ign. It goes through the idiot light or a resister built in the harness. One wire on the regulator is hot all the time. The field wire feeds to the feild on the alt. Yes the regulator controls the voltage output of the alt. When it gets to the preset voltage ,about 14, it tapers down to maitain that voltage. The amperage takes care of itself because the alt. will only put out its max. built in curent. Unlike a gen. which will destroy itself if its uncontrolled.

Ranger,

I am not an expert, but here are some ideas. I think you might have tried this, but I will mention it anyway. To "prove" the alternator, REMOVE THE DA PLUG from the back, and with the truck running, use a wire to jump battery voltage to the "F" terminal on the alternator.

This will put the alternator into full field charge, and with your meter on the battery, you should see the voltage climb to 14 + volts. Don't do this for an extended period of time.

With the key off, the regulator should show battery voltage on #3. With the key off, #4 should show zero volts and when you turn the key on, it should show your reduced voltage. I think you said 7.5 volts.

The schematic shows "F" on alternator to "F" on regulator. "R" on the alternator to #2 on the regulator. These wires, as was noted above have to have continuity...no breaks! I don't know what values in voltage they will have, but if all wires are intact and you can get the alternator to output by jumping the "F" terminal, it would seem the regulator is your culprit.

I know the "no returns on electrical items" is a drag, but you can see why this is the policy.

If you can eliminate the alternator, you have half the battle won. I don't think adjusting the regulator is an option open for anyone other than a experienced repair person. If all else fails and another alternator is required, a internally regulated one would be a good choice, and it could be integrated into your existing system. Good luck.

Stuart

Here\'s a link that may help.

Make sure the regulator is grounded good, if not won't work.
If working right the alterator should run every thing on the truck. The battery is really only to start the truck and the alterator keeps the truck runing. If the alterator is working right you can undo the battery and the truck will keep running. also make sure the ground to the motor, frame, body is in good shape. new regulator are not adjustable the old one were if you know what you are doing, you can fry the battery if you over charge it often.

super250six

Thanks for all the help!!! Never trust new parts form the parts store. Between 2 failded regulators (bad form the store) and a bad wire, not broken but could have been a culprit, so I replcaed them all. And I now have a charging system that works. Yes the one wire newer model alternator may be in the future when money is more fluid.
Thanks again to everyone....
Merry Christmas to you and yours from us up here in the NorthWest.
I will be a happy plow'n kinda guy tomorrow.

Plowing is odne for today the truck worked great, thanks to everyone who helped. The best part was last night I finally installed my new defroster duct I got from the American classic parts warehouse on this page. I have never had it so good to have heat and defrost while plowing.
Merry Christmas...

Ranger,

What could be a better Christmas gift than a purring alternator and a frost free window!


Stuart