Voltage Regulator

[theskytoucher]

I think my Voltage regulator is bad but is there any way to test it before throwing money at the problem??? The alternator tested good so i think the regulator is the next step right?
Well ill explain my circumstances a little for you, I went to the next town over 20 miles or so on saturday after dark didnt notice any dim lights or anything, picked up my girlfriend got tin the truck and all the lights were dimmer than usual, athough this happens sometimes but doesnt stay for very long, so we go about our date and i take her home no big deal. Well on the way home i really noticed the dim headlights. Drove the truck everyday since then in the day and forgot about it. Today after work my truck cranked about 3/4 of a turn and stopped ok get the jump box starts right up, run to the store shut the truck off same thing jump it and get it home! I did the old start the engine pull the battery cable and it died so i pulled the alternator and took it in and got it tested no problems!!! reinstalled it jump the engine drove it for about 10 min shut it off wouldnt start. So i checked all my connections same thing!!!
So does this sound like the regulator or what????
Thanks for the help

[FORDification]

It could be...but it could also be a dozen other possibilities. A battery not charging can be caused by things like loose or corroded battery clamps and/or cables, loose belt, bad battery, bad alternator, loose/corroded alternator connections...or a bad voltage regulator. However, you can take that into any decent parts store and they can test it for you, just to eliminate that as a possibility.

[fitzwell]

first, quit taking the cable off to see if it works. Throws a huge voltage spike thru the system. Not a good idea on our trucks, and a good way to wipe out a computer on any late model vehicle. To check alt output, unplug the reg & jump from the "A" connection th the "F" connection in the harness, this puts the alternator into full field. When you do this you should hear the alt as it tries to charge all it can. Another way to check output is to put a small screwdriver close to the bearing at the rear of the alternator case. You should feel a magnetic pull if the unit is working. Be careful not to touch the bat post.

the number you want to see if using a voltmeter is between 13.8-14.2. This may seem a little high, but remember, the alternator is designed to maintain the battery , not to "charge" it.

[theskytoucher]

ok guys i have been chasing this gremlin ever since i first posted this!!!! As stated i started with a new alternator, didnt fix the problem, (the old one was bad) got a new voltage regulator, didnt fix the problem, Put in a new battery this worked up until tonight when al the juice in the battery drained out! (old battery had at least to dead cells, i had them stop checking after that) Also i took the alternater wiring harness out of all the wrapping and checked for any visible shorts then put a continuity tester along all the wires and they all checked out so i put it back in the truck!!! After i put the battery in i coyuld tell the system still didnt have the right voltage so i took the new alternator back to napa and they tested it it was bad got a new one (had them test it first it was good) same story it isnt charging!!!! I have no idea where to go from here? Any ideas on something i have missed??? I tried to not just throw parts at it but that is the way it went down and i still dont have a charging system!!! I have gone through all my connections they are all good i have traced all the wire to make sure they are in the right places i just cant find the problem and this is my daily driver so i need to get this fixed as quickly as possible!!!! Thanks!

[theskytoucher]

and fitz how is the best way to check the voltage coming out if the alternator would that be jumping "A" to "F" with a voltage meter???
Thanks

[fordman]

you could have a draw on the system that isn't shutting off some how. to check for a draw start the truck let it run turn off everything. close the door. take the neg bat cable off. if it dies its the alt. but if it doesn't then put a test light between the neg bat post and the neg bat cable. if it lights up you have a draw someplace. if you have a draw then pull one fuse at a time until the draw goes away. once you find out which circut it is then you can chace that circut down.

[theskytoucher]

A little theory here that you guys can tell me if im right or wrong about! If i pull both the wires off the back of the alternator (excluding the ground) the larger terminal should show power while the engine is running right?? Cause mine doesnt!!

[fordman]

the larger one to the large terminal is the batt connetor wire. i don't know if it should be hot or what. i would think it should be.

[theskytoucher]

That was my thought im gonna go get the alternaotr tested at a different store now to see wat they say!!!!!

[theskytoucher]

double post!!!!!!!!!!!!!!!!!

[fordman]

what year truck is this?

[theskytoucher]

Well this alternator is bad too!!!! And now im starting to get mad cause i hate when i buy something and it doesnt work!!!! This is on a 68. and i figure you are going to give me a link to the wiring diagrams but i have already looked at them and checked every wire in the charging system to make sure it goes to the right place and inst shorted out!!!! So either im screwed up in the head and am not doing something right or napa reman alternator really sux!!!!

[fordman]

i was going to look that wire up and see if it was a hot wire when it was running

[theskytoucher]

i see

[theskytoucher]

ON the wiring diagrams for the charging system it has a Field relay next to the voltage regulator, i do not have the on my truck all the wires that are supposed to be connected to that relay go into a factory looking connector which has 12v all the time!!! is this a necessary item???

BUt the system worked for two years before now all the sudden it would work no matter what i do!!! All the wire look good, and none of them are shorted out so...