So I have a 302 with HEI dizzy, but it will only start if I connect the Black-yellow straight to battery. This is how it was wired when I bought it, tried to connect alternator and it won’t crank. I know it’s something simple but show me the light thanks
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Starting Issues: Thinking Out Loud
- Thread starter 1strodeo
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So is it not cranking at all? Or will it crank and just won't start without the added wire?
The Black w/yellow wire is the old battery-to-cabin wire harness I think. Which would explain it not doing anything until you connect it to the battery.
It could also be the alternator side of the harness, since I don't see that in the picture either, but the other explains things more quickly. Usually the Black with a Yellow wire next to it is the battery harness.
Depends on how the rest is connected.
Is this a new harness? Looks all shiny and clean, but is the factory colors still. So either it's original or Painless.
The alternator charge wire is always Black w/yellow, but even though the part you're showing should be just Black only, or Black w/red stripe depending on year, I've seen that bit of wire have a yellow stripe as well. A little more digging should let us know what is what.
The Yellow wires next to it run the voltage regulator on the wheel well or fender skirt (is this the '72, or '66?) and not sure what the second one is off the top of my head.
Originally the starter relay there on the wheel well with the battery wire going to it would also have had the extension of the Black w/yellow wire (along with a fusible link) connected right under the battery cable on the big stud.
I don't see anything there currently.
Is this a new to you setup? Ever worked at all since you've had it.
Got more pics? Such as the back of the alternator and where it's wiring goes?
Thanks. Good luck.
Paul
The Black w/yellow wire is the old battery-to-cabin wire harness I think. Which would explain it not doing anything until you connect it to the battery.
It could also be the alternator side of the harness, since I don't see that in the picture either, but the other explains things more quickly. Usually the Black with a Yellow wire next to it is the battery harness.
Depends on how the rest is connected.
Is this a new harness? Looks all shiny and clean, but is the factory colors still. So either it's original or Painless.
The alternator charge wire is always Black w/yellow, but even though the part you're showing should be just Black only, or Black w/red stripe depending on year, I've seen that bit of wire have a yellow stripe as well. A little more digging should let us know what is what.
The Yellow wires next to it run the voltage regulator on the wheel well or fender skirt (is this the '72, or '66?) and not sure what the second one is off the top of my head.
Originally the starter relay there on the wheel well with the battery wire going to it would also have had the extension of the Black w/yellow wire (along with a fusible link) connected right under the battery cable on the big stud.
I don't see anything there currently.
Is this a new to you setup? Ever worked at all since you've had it.
Got more pics? Such as the back of the alternator and where it's wiring goes?
Thanks. Good luck.
Paul
Thanks Paul, sorry here are better pics...this is the 72 and this is how it was wired when I got it, only with alligator clips %). It had a dusty crusty old alternator that was not even hooked up, so I grabbed a better one I had from a Mustang and added a new alternator harness from JBG. Also it had NO voltage regulator, so that's what's in the box. It starts and runs just fine with this configuration.
When I connected the new alt harness I got nothing, no crank. Never hooked up the regulator, but it's not part of the starting circuit so, first things first. Been looking over diagrams trying to figure out how that temporary connection to the battery was lost when the alternator was connected. When you said...
"Originally the starter relay there on the wheel well with the battery wire going to it would also have had the extension of the Black w/yellow wire (along with a fusible link) connected right under the battery cable on the big stud.
I don't see anything there currently."
...then it made sense, and that's probably the culprit. Will follow up thanks again
Jeff
When I connected the new alt harness I got nothing, no crank. Never hooked up the regulator, but it's not part of the starting circuit so, first things first. Been looking over diagrams trying to figure out how that temporary connection to the battery was lost when the alternator was connected. When you said...
"Originally the starter relay there on the wheel well with the battery wire going to it would also have had the extension of the Black w/yellow wire (along with a fusible link) connected right under the battery cable on the big stud.
I don't see anything there currently."
...then it made sense, and that's probably the culprit. Will follow up thanks again
Jeff
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Nice looking wiring.
On a stock '72 starter relay there would have been 5 wires. On your newer style there would be 4.
You would need these to get the basic functions of the truck:
1. Starter cable (one of the large posts)
2. Battery cable (other large post)
3. Red w/blue "S" wire (on the small post)
4. Black 10ga wire (on same stud as battery cable)
The last one, the Black 10ga wire powers the entire truck and literally nothing can work without it in the original harness.
So find the 2 Black wires, verify their routing and function (so that the ammeter reads properly if for no other reason) and connect one to the BAT terminal of the alternator and the other to the same stud as the battery cable that you used with your jumper wire.
In case we have not talked about it before, those 10ga Black wires are literally the same wire. Just as if you were holding two ends of the same wire in your hands, this wire is one big loop from the engine compartment, through the cabin and back out to the engine compartment.
One side is the battery to power things when the engine is off. The other side is at the alternator for it to power everything AND to charge the battery when the engine is running.
The only break in this wire is behind the ammeter where they installed a push-connector for servicing the gauge.
If this connector ever becomes disconnected, then nothing works. And I mean nothing.
Just like you are experiencing with the wire disconnected from the battery. You can't have power without the battery. And right now you don't have anything connected to the battery to utilize that power.
Paul
On a stock '72 starter relay there would have been 5 wires. On your newer style there would be 4.
You would need these to get the basic functions of the truck:
1. Starter cable (one of the large posts)
2. Battery cable (other large post)
3. Red w/blue "S" wire (on the small post)
4. Black 10ga wire (on same stud as battery cable)
The last one, the Black 10ga wire powers the entire truck and literally nothing can work without it in the original harness.
So find the 2 Black wires, verify their routing and function (so that the ammeter reads properly if for no other reason) and connect one to the BAT terminal of the alternator and the other to the same stud as the battery cable that you used with your jumper wire.
In case we have not talked about it before, those 10ga Black wires are literally the same wire. Just as if you were holding two ends of the same wire in your hands, this wire is one big loop from the engine compartment, through the cabin and back out to the engine compartment.
One side is the battery to power things when the engine is off. The other side is at the alternator for it to power everything AND to charge the battery when the engine is running.
The only break in this wire is behind the ammeter where they installed a push-connector for servicing the gauge.
If this connector ever becomes disconnected, then nothing works. And I mean nothing.
Just like you are experiencing with the wire disconnected from the battery. You can't have power without the battery. And right now you don't have anything connected to the battery to utilize that power.
Paul
Thanks a bunch Paul. This makes total sense now. Not only is the black wire not connected at the starter relay, THE INSTRUMENT CLUSTER IS NOT INSTALLED ;D%)
so even if I did connect it, the loop would still be broken. I would have mentioned the cluster but silly me didn't think that would have anything to do with it (read your diagrams much Jeff?) I'm confident (yes I'm very optimistic) that once I connect the black wire to the battery post of the relay and either install the cluster or jumper the Ammeter connections that it will be good. Thanks so very very much.
I ran the hardtop for the 72 over to the guy doing my 66 tub and on the way home stopped by Tom's (tpatton75) to borrow his spare hood for fitment over the HEI. In other words, I didn't have time to look into this last night, but will tonight. Thanks again -Jeff
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Cool. But one thing still stands out.
Remember I said that Black w/yellow wire with the two yellow wires in the plug looked more like it should be at the back of the alternator? Seems that's correct because, knowing as we do now that it's still disconnected at the ammeter, if you'd simply connected the battery to the other Black wire you still would have had no power. But connecting it to the alternator side of the Black wire would at least get power to some accessories (and apparently the ignition switch) because they are on that branch of the wire.
So it does seem that this wire you're using is to connect to the alternator.
Guess I better go look at some stock wiring again to re-familiarize myself with it. I thought the two Yellow wires would have been on the battery side, and the yellow stripe on the Black wire seemed to be wrong for the battery side.
Broncos of different years either had a solid Black wire on the battery side, or a Black wire with a red strip.
Mostly I'd say the red stripe was a mistake to use there, as that is also Ford's color code on some ground wires! Bad juju to mix those up for sure.
Anyway, are those just cleaned up original harnesses? Or are they reproductions from someone? They sure look brand new to me. Curious who's making them and if aftermarket, what you think of them?
Sounds like you're on the right track. Don't normally fire things up with power until everything is connected. Too many chances for strange goings-on.
Good luck.
Paul
Remember I said that Black w/yellow wire with the two yellow wires in the plug looked more like it should be at the back of the alternator? Seems that's correct because, knowing as we do now that it's still disconnected at the ammeter, if you'd simply connected the battery to the other Black wire you still would have had no power. But connecting it to the alternator side of the Black wire would at least get power to some accessories (and apparently the ignition switch) because they are on that branch of the wire.
So it does seem that this wire you're using is to connect to the alternator.
Guess I better go look at some stock wiring again to re-familiarize myself with it. I thought the two Yellow wires would have been on the battery side, and the yellow stripe on the Black wire seemed to be wrong for the battery side.
Broncos of different years either had a solid Black wire on the battery side, or a Black wire with a red strip.
Mostly I'd say the red stripe was a mistake to use there, as that is also Ford's color code on some ground wires! Bad juju to mix those up for sure.
Anyway, are those just cleaned up original harnesses? Or are they reproductions from someone? They sure look brand new to me. Curious who's making them and if aftermarket, what you think of them?
Sounds like you're on the right track. Don't normally fire things up with power until everything is connected. Too many chances for strange goings-on.
Good luck.
Paul
I don't know how well this pdf will show up but I'll try it (thanks Steve83)
The little alternator harness is from JBG, harness under dash looks to be original and I assume the section of harness coming through the passenger side firewall is part of that but who knows. I may pull the dash to clean things up and make it easier to do all this (speedo, heater controls etc)
and i'll take your advice and not fire it up again until all connections are made
The little alternator harness is from JBG, harness under dash looks to be original and I assume the section of harness coming through the passenger side firewall is part of that but who knows. I may pull the dash to clean things up and make it easier to do all this (speedo, heater controls etc)
and i'll take your advice and not fire it up again until all connections are made
