Alternator Wiring Conundrum

[Thunderfoot]

The "Alt light" is controlled by the stock Voltage Regulator, it supplies the ground for the light to come on, and then when the alternator starts charging it opens up this connection to ground so the light goes out. I'm guessing you still have the STOCK voltage regulator on the truck with the wire harness plugged into it, unplug it if you do... If you don't then you have that wire grounded somewhere for the light.
Of course with what you have you will not know when the alternator stops working unless you have a Voltage gauge.

[heviarti]

yeah, I'm actually looking to have that light work right. I have a "car quest self diagnosing voltage regulator" installed. I have a component diode I can patch into the harness if that'll do the job. If not, well, if the light dims I know I've got problems.

[SoCalExile]

Well guys it seems I still have issues.

Since getting the Goose back on the road, the battery charge has been getting weaker and weaker 'til finally I had to jump it.

I drove it to the parts store and had them put the tester to it while in the truck...and sure enough, the battery isn't getting charge. I then pulled the alternator out and had them bench test it....which it passed.

So it seems something is not hooked up right.

[fordman]

did you have the regulator tested? i think the regulator is the heart of the charging system. it tells the alternator to charge or how much to charge basically.

[SoCalExile]

I don't know if they tested the regulator or not. They just hooked it up to the bench tester.

I ended up getting the stuff to run a 3-wire connection rather than the 1-wire it's supposed to be now.

In the process, I got a circuit light and hooked it up between the disconnected negative battery cable and the negative post on the battery...yup, got a light.

I then started pulling fuses (breaking a few) and the flasher relay...the light is still on.

I then went under the hood....pulled the two little plugs going into the starter relay...still on.

Then I pulled the alternator cable...the light goes out!

I then put the cable back on the alternator and then started unplugging the wiring harness from the horn and starter relays.The light didn't go out until I finally unplugged the whole thing.

So next I believe the thing to do would be to run a wire from the alternator post to the starter relay to ensure that it is Bubba's wiring harness that's creating the circuit and not something else...

Thoughts?

Update: Used some 10-gauge wire and ran it from the battery post on the alternator to the post on the starter relay where the positive cable connects...no light.

Pic of Bubba's wiring harness:



Update 2: Turns out the circuit is completing via the engine block! The negative post is grounded on it, and it's conducting through the block and the alternator mount.

What can I do to fix this?

[SoCalExile]

After idling around a school parking lot (letting my 13y.o. get some wheel time) for about 20 minutes, my battery didn't have enough charge left to get home. When I finally got home the running voltage was 12.15 or so (12.03 with the headlights on).

Methinks it's a good idea to ditch this charging setup and replace it with the Ford-style one it was designed with.

[fordman]

the negative off of the alternator is touching the block? its a ground it shouldnt matter if it is. it sounds like the regulator is bad. they should charge more than that while running. something around 13.2 or more.

[heviarti]

yes, definitely time for testee testee regulator. If you are having a ground related issue, the best way to make it evaporate is as follows: Find a local shop that makes battery cables. Have them manufacture two cables for you, one that comes from beneath your ground pad on your block and hooks to your frame, the other from the ground pad or the frame to the body. Before you bolt anything on, take a 90° die grinder with Roloc pads and take each spot where a cable will be bolted down to the metal. If you're a real stickler, also tap the hole in the ground pad. Assemble it all with dielectric tune up grease. Clean all excess grease with a rag and possibly a quick drying solvent. Spray paint the remaining exposed metal That will give you reliable ground to almost any metal surface on your rig.

Still nobody with any ideas on making the charge light work with a Delcotron?

[fordman]

actaully you have to ground the enigne so the firewall strap will ground the cab. the cab sits on rubbers and isnt grounded to the frame. however it is a good idea to ground the frame to the body.

and i dont know anything about john deere or Gm delco.

[fitzwell]

The two wire connection on the delcotron should be; #1 terminal should be ignition switched, (possibly a wire from the "I" terminal on tht existing regulator), #2 is jumpered to the charge post of the alt. This is your voltage sense wire. Large bk/yel goes to the charge post. The alt should ground thru the mounting points, but a ground cable from the pivot point bolt to the frame isn't a bad idea.

as always..

[SoCalExile]

The two wire connection on the delcotron should be; #1 terminal should be ignition switched, (possibly a wire from the "I" terminal on tht existing regulator), #2 is jumpered to the charge post of the alt. This is your voltage sense wire. Large bk/yel goes to the charge post. The alt should ground thru the mounting points, but a ground cable from the pivot point bolt to the frame isn't a bad idea.

as always..

This is what I'm running with now after seeing that low charge voltage on a 1 wire. Now it's charging at 13.70 volts and not seeing any issues after it sits overnight.

I did run a 10ga wire from the negative cable mounting point to the frame.

So far so good.

[heviarti]

Fitzwell: isn't that what my photograph shows? I still don't have a working charge light.

I'm actuallywondering if I can't delete the regulator leg of my harness, what with the regulation being in my alternator.

[Thunderfoot]

Fitzwell: isn't that what my photograph shows? I still don't have a working charge light.

I'm actuallywondering if I can't delete the regulator leg of my harness, what with the regulation being in my alternator.

As I stated before...

The "Alt light" is controlled by the stock Voltage Regulator, it supplies the ground for the light to come on, and then when the alternator starts charging it opens up this connection to ground so the light goes out. I'm guessing you still have the STOCK voltage regulator on the truck with the wire harness plugged into it, unplug it if you do... If you don't then you have that wire grounded somewhere for the light.
Of course with what you have you will not know when the alternator stops working unless you have a Voltage gauge.

To clarify more...
You will want to unplug the wire harness from the stock FORD external Regulator... it isn't doing anything now other then keeping your Alt light on...

To get your Alt light to work correctly you can try taking the Green/red striped wire that is going to the stock FORD external Regulator and wire it directly to the #1 terminal on the GM alternator (you must remove the wire you have there now) and it should (in theory work). Some internet info... http://www.oldengine.org/unfaq/10si.htm

FYI, for those that want to use a "1" wire GM alternator... it takes a special Regulator in the alternator to do this, you can't just take a regular GM alternator and try to wire it up "1" wire like, it wont work.

[heviarti]

Thunderfoot: that worked. Greed/red to 1. My charge lamp shuts off. There are a few issues with that setup.

It was wired to the Red/black out of the old alternator head. Key off it reads 1.4v. Key off the Green/red reads a full 12v. no bueno, no? Seems like it would cause a parasitic draw. I could be wrong.

As a side effect the 'light-off' wiring has made it take a few seconds for the ignition to kill. I guess I'll have to wire that diode in now. I'll just have to figure out which way to point it. I'm sure if my state of charge was better than start/idle that machine wouldn't shut down.

But, good call. once the bugs are worked out I think this'll be good.

When I said delete the regulator leg, I mean actually delete the wiring. There's about six wires sitting in my harness I don't need at that rate. I didn't unplug the regulator because I had something to tell me the ignition was engaged, and if it dims I have problems.

Once this is licked that only leaves two or three electrical probs with the pickup.

[Thunderfoot]

Just to confirm: the Green/red stripped wire you used was the one going to the Voltage Regulator #904 in this diagram http://www.fordification.com/tech/wirin ... rging2.jpg This wire should not have any power on it with the key turned off.

What year is your truck? I'm not finding a Red/black striped wire that goes to the alternator. There IS a Black/red striped wire that is the GROUND wire used on the Alternator to the Voltage Regulator #26 in that diagram, should have no volts...