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WH one wire alternator help

CA650

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Joined
Apr 13, 2013
Messages
273
people,

this is an embarrassing post but i’m going to post it anyway.
somehow, I failed at a one-wire alternator installation.

i’m on my third alternator now looking for some advice or diagnostic to run or... someone to come over and buy me a drink or something.

here’s what happened:
I did the timing chain, cover and seal replacement in an early thread with lots of help from this forum

got through that.

swapped a WORKING alternator out that was old but I did it anyways because I was in there and because I am stupid

once everything was back together I noticed the voltage was low in the cab. I have modern gauges so I could just see it pegged to like 11.5 volts

tried to debug the new alternator and didn’t notice anything wrong in the wiring.. so I said no problem.. switch back to the old alternator... it didn’t work?

so I thought ok, some fuse or some misplaced wire or short, can’t be a big deal only 4 wires go into there. checked the grounds etc. nothing so then I got pissed

I decided to teach the truck a lesson and bought a 3rd ONE WIRE alternator. I wanted more amps anyway and i thought ok if the regulator might be the problem the. let’s get rid of that PoS too. I was sort of daring the truck not to work at this point and throwing the kitchen sink at it.

Some guys at WH suggested swapping the pulley for a two groove vbelt pulley to avoid squeaks on the new alternator - no problem I did that sounded good too just in case the truck tried to fight back again and squeak wfter the alternator was fixed. . also bought a nice CVF 302 alternator bracket that made it easy to get the belts tight etc. just in case I wasn’t getting a good ground to the block on the alternator bracket

so now i’m on alternator #3
twin v belts spinning fine

no juice?
battery and everything reads under 12 volts
I drove around, revving the engine thinking it might just need more rpm to excite the alternator.. nothing

I confess I did not read the alternator instructions because (im like that)
but for gods sake it has ONE wire and a pulley. wtf am i doing wrong?
anything obvious to check? is there supposed to be a ground on this second alternator or is the block good enough like your starter?

attached are the parts AND two videos where I use the voltage meter to test a few spots around the engine while it runs.

lot of work and not the result I was hoping for.
split my old starter solenoid apart during the process and ended up replacing that too. at this rate I will have a new but non working bronco one part at a time by end of august

any ideas will be appreciated

https://youtu.be/wIanrpi_Ytc

https://youtu.be/qDV-e5g53qI

parts are these:

https://www.cvfracing.com/stealth-black-ford-small-block-alternator-bracket-289-302-1969/

https://www.wildhorses4x4.com/product/Hi-Output_Alternator_130-Amp/Bronco_Starters

https://www.wildhorses4x4.com/product/Battery_Charge_Cable_AMG_fused/Bronco_Starters

https://www.summitracing.com/parts/SUM-G3949B
 

chuckji

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Sr. Member
Joined
May 5, 2017
Messages
470
Loc.
SE Michigan
Trying to see how you have it wired in the video, but it’s a little tough.
Looks like you’ve got the alternator output wire (red) connected to the fuse, but can’t tell where it goes from there.
Is it connected to the starter solenoid? If so, are you sure you’re connected to the battery side of the solenoid?
 
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CA650

Full Member
Joined
Apr 13, 2013
Messages
273
yep
the wire goes from the alternator to the fuse
the fuse is in the socket
then from the fuse to the plus side of the solenoid

truck starts. measure right from the negative side of the battery to the output wire of the alternator.. reads only like 11.6 volts or so

it’s so simple I can’t believe it’s not a problem inside the alternator

here’s a better look at how the wires flow.

https://youtu.be/29y2xHSU_AA
 

DirtDonk

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Messages
51,619
Still movin' around too much for my slow eyes to see everything, but I think I got the gist.
What is that large Black (ground cable?) laying over the other wires? Whatever it is, get it out of there and away from the other bits. Might nothing happen in the short term, but eventually something is going to wear through and let the smoke out.
Normally in an engine compartment, nothing should touch nothing unless nothing ain't moving. If you get my meaning...;D;)

So the White w/black stator wire is connected at both ends?
The Yellow w/white wire is connected at both ends?

With the engine OFF, measure voltage at the alternator side of the cable. Should read battery voltage too.
If it does not, then something is wrong such as the fuse being blown. If it does, then maybe a voltage drop test on the wires. I realize everything is brand new, but it's possible for something to be defective anyway.

Remove the gray connector and take readings on the Yellow wire. Should still be reading battery voltage.

I would lean more towards the alternator itself rather than the cables, but anything is possible.
We know your battery and starter cables are good, or you would not be able to start the engine.
We know the alternator is connected to the battery side of the starter relay, so it's effectively in direct contact with the battery. Good there...

Let us know about the two small wires, then we can go from there.

Paul
 

DirtDonk

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A ground is a good point. But not to the engine in this case, because the starter will crank. If the starter is cranking, the ground is good.
But with all that paint, is the alternator grounding to the engine? I don't know how much trouble not being grounded would cause, but it's a good idea to test it anyway. If the bolt hole and mounting bosses are all painted up, there's a good bet that the ground is at least minimal.

Should be able to find out quickly by using a jumper wire from the battery negative to the alternator casing. If the voltage jumps up, you're on to something. If not, then Plan-B...

Paul
 

DirtDonk

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Anyone ever full fielded a 3G? Is there a "poke here" hole in the back?

Never tried it on a 3G, but if one is there then that would be a next test too.

Paul
 

gr8scott

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Is there a "poke here" hole in the back?

Yup, don't know how to do it though. This is the same unit that CA650 is trying to get working. Picked it up from WH in 2011, has never let me down (yet).

Hey CA650, is that a transmission cooler line going over your alternator?
 

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gr8scott

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Also, are you giving your throttle a decent rev after startup? It's self exciting, so it needs a good rev to get going.
 

Broncobowsher

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I would also doubt the dash mounted volt meter and old wiring it is attached to is that good. Have you put a real meter on the alternator itself?
 
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CA650

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I would also doubt the dash mounted volt meter and old wiring it is attached to is that good. Have you put a real meter on the alternator itself?

in the attached video links I put a hand held volt meter on the actual cable coming off the alternator and in other spots. all spots read the same.. some number just below 12volts
 
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CA650

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Also, are you giving your throttle a decent rev after startup? It's self exciting, so it needs a good rev to get going.

yes thx I drove for some time and revved the engine steady at 3k rpm
trying to make sure the alternator had more than sufficient rpm and time to do its thing. I think it’s the alternator and i’m going to swap in a new one and see.
 
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CA650

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Yup, don't know how to do it though. This is the same unit that CA650 is trying to get working. Picked it up from WH in 2011, has never let me down (yet).

Hey CA650, is that a transmission cooler line going over your alternator?

yes it’s the transmission cooler line running up near the alternator
 

DirtDonk

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Yup, don't know how to do it though.

Well then I guess I'll have to read up on the procedure.;D
But if it's like others, you simply poke a metallic object in there (typically a small screwdriver) which shorts out the regulator and causes the alternator to put out it's maximum output.

And by "shorting out" I mean it applies battery voltage to the Field windings (hence the name "full-fielding"), essentially bypassing the regulator.

It should just be a simple matter of sticking it, as Bill Murray used to say, "in the hole" and watching the volts go up.
But since it would be an expensive mistake if I got it wrong, I'm going to read about it before I ever do it to one.

Paul
 

EPB72

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As far as full fielding look at grtscott photo on the back of the voltage regulator it says ground here to test with a little arrow run a jumper ground to that location under the little red plug..
 
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CA650

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Yup, don't know how to do it though. This is the same unit that CA650 is trying to get working. Picked it up from WH in 2011, has never let me down (yet).

Hey CA650, is that a transmission cooler line going over your alternator?

guys, I am going to ask a potentially embarrassing question here.
I literally connected “one wire”to this alternator

what is that other black wire connected to the back of gr8scotts alternator that you said is the same unit? I thought this alternator got its ground through the housing and the bolts to the block.

I did this: see complex installation diagram here
https://s3.amazonaws.com/cdn.wildhorses4x4.com/downloads/WH/6013 07-25-18.pdf
 
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DirtDonk

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You are correct that it's a ground. Sort of an "auxiliary" or "backup" ground if you will.
Yes, they ground through the case, but I brought it up before because of all that nice paint you have which keeps anything from grounding to anything through the cases.
You still have the bolt though, so if the threads are good and clean, and the bolt is good and clean, and the bolt touches the alternator good and clean, then you have a ground.
But my practice is to never assume and that's why I suggested a jumper ground, even if just temporary, to see if that has anything to do with the no-charge situation.

Thanks EPB for the grounding advice. I wasn't sure if it was just a "poke some metal thingy here" or not. That answers that question.

But a second though occured to me (happens sometimes) that even if this causes the alternator to charge, this indicates that it's a bad regulator or connection. Correct?
If so, then it's still the alternator assembly that is at fault so needs to be replaced.

Thanks.

Paul
 

bmc69

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11.8 Volts is a fully discharged battery. Dead parrot. So if its still cranking and running the truck..it cannot be really 11.8V.
 
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CA650

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11.8 Volts is a fully discharged battery. Dead parrot. So if its still cranking and running the truck..it cannot be really 11.8V.

I think it’s 11.9 when the vehicle is running meaning the battery is discharging while running the vehicle and it’s 12.1 or so with the vehicle off

here is a closer look at the alternator and a video of the voltage meter with the engine off reading 12.1 on both sides of the alternator fuse

https://youtu.be/HGAHWt7DHVg

Paul (corrected) you’ve mentioned the paint a few times. the cvf mounting brackets are new and are not painted, the bolts are new and are not painted. the top of the pegs on the water pump cover are sanded and brushed to bare metal and no paint went into the holes on the pump cover or the block and the block threads were cleaned and I ran a threading tool through them to be sure the threads where shaped nice and that they were clean. also as you pointed out earlier the starter has always fired up strong and it’s grounded only to the transmission bell housing connected to the block.

only suspect I have left is that unlike gr8scott I did not run an additional ground wire to that empty bolt hole on the back of my WH alternator

picture attached.
 

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DirtDonk

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Nah, I think you just got a bum alternator.
While the additional grounding is a good thing, from your description you should have plenty of metal-to-metal contact between the alternator and engine assembly to more than cover things.

I suggested a temporary ground to the case just to confirm and eliminate that as a possibility, before going to any great trouble to make an additional permanent ground wire.

Sounds to me like there is either a flaw somewhere in the gray connector and it's wiring, or in some internal function of the alternator.

Paul
 
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