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We're finishing up the 3G alt wiring on my sons 76 F100. While we were attaching some things to the battery side of the solenoid, this Blue wire came out pf the molded piece in the picture. The other end of this wire is stripped and wrapped around the battery side post. Any idea what it is? Thanks!
That looks like it could be the fusible link.
Hard to tell from the picture.
When we did ours 3G upgrade it was deleted.
Add a couple more from a wider view.
That looks like it could be the fusible link.
Hard to tell from the picture.
When we did ours 3G upgrade it was deleted.
Add a couple more from a wider view.
My '79 did not have that type of setup. Are there any other wires going in to, or coming out of, that block? Looks a lot like a junction/splice cover, but since it goes to the battery side of the starter relay/solenoid it's likely the fusible link / charge wire from the old alternator like John89 said.
Since you're changing to a 3G anyway, why are all the old wires still laying around? I see the old alternator wires, which should be removed to get them out of harm's way and keep you from having a short later. Were you just waiting until the 3G was installed and verified working? I think it's easier to remove them while you're working, but that's just me.
I see that they're pretty faded. Seen that a lot, but not every truck suffers that fate.
If I remember the '76 has the regulator over on the core support rather than on the fender skirt? I know sometimes the wires are loomed up with other un-related wires, making it harder to remove the ones you don't need and leave the ones you do. But since this is a re-wire 101 kind of, it's only one more step to un-wrap the harness where you're working and get rid of un-needed and potentially trouble some wires and if you want, re-wrapping the leftover wires back up to clean things up and protect them for the long haul.
No matter what though, you do NOT want random wires attached to the battery so you really need to remove the end of the Blue wire attached to the battery side and unearth where the other end goes and if they are previous generation alternator wiring, get rid of them.
So follow them down, unwrap them if needed to see what color and where they go.
Why is there a Green wire (new one) on the "I" post of the starter relay?
Is the Yellow wire on the battery side for the sensing wire of the new 3G? Could the Green one be taking the place of the old Green w/red wire on the new 3G?
If so it's kind of in the wrong place. It'll likely work of course, but it's a finicky connection and can work loose over time with just that push-on connector to hold it in place. Leaving you with a no-charge situation at random times while driving around.
The original Green w/red wire is right there in that 2-wire connector above it and should have the same function of 12v with the key in the ON and START positions. If it's working, then it's the better choice I think.
In fact, you can clean up the starter relay/solenoid wiring by re-using that 2-wire plug. Simply use the existing wires (Yellow and Green) to handle the same functions as with the original alternator.
My '79 did not have that type of setup. Are there any other wires going in to, or coming out of, that block? Looks a lot like a junction/splice cover, but since it goes to the battery side of the starter relay/solenoid it's likely the fusible link / charge wire from the old alternator like John89 said.
Since you're changing to a 3G anyway, why are all the old wires still laying around? I see the old alternator wires, which should be removed to get them out of harm's way and keep you from having a short later. Were you just waiting until the 3G was installed and verified working? I think it's easier to remove them while you're working, but that's just me.
I see that they're pretty faded. Seen that a lot, but not every truck suffers that fate.
If I remember the '76 has the regulator over on the core support rather than on the fender skirt? I know sometimes the wires are loomed up with other un-related wires, making it harder to remove the ones you don't need and leave the ones you do. But since this is a re-wire 101 kind of, it's only one more step to un-wrap the harness where you're working and get rid of un-needed and potentially trouble some wires and if you want, re-wrapping the leftover wires back up to clean things up and protect them for the long haul.
No matter what though, you do NOT want random wires attached to the battery so you really need to remove the end of the Blue wire attached to the battery side and unearth where the other end goes and if they are previous generation alternator wiring, get rid of them.
So follow them down, unwrap them if needed to see what color and where they go.
Why is there a Green wire (new one) on the "I" post of the starter relay?
Is the Yellow wire on the battery side for the sensing wire of the new 3G? Could the Green one be taking the place of the old Green w/red wire on the new 3G?
If so it's kind of in the wrong place. It'll likely work of course, but it's a finicky connection and can work loose over time with just that push-on connector to hold it in place. Leaving you with a no-charge situation at random times while driving around.
The original Green w/red wire is right there in that 2-wire connector above it and should have the same function of 12v with the key in the ON and START positions. If it's working, then it's the better choice I think.
In fact, you can clean up the starter relay/solenoid wiring by re-using that 2-wire plug. Simply use the existing wires (Yellow and Green) to handle the same functions as with the original alternator.
Having fun yet?
paul
Thanks for your reply Paul!
Regarding the old wiring, as you mentioned above, we've just left it in place until the new setup is in and working properly. It's wrapped up in the factory loom pretty well so it will take some time to get it out of there but our plan is to remove it.
As for the other wiring, there's a picture of the 3G setup in the sticky notes on this site and we're following that diagram as best we can. It shows the yellow wire coming off the alt and that get's attached to the battery side of the solenoid. The Green/Red wire is the head scratcher for me. I know that it's current location on the "i" post on the solenoid is the wrong spot but my son (he's 17) sometimes get's ahead of himself (because he's impatient) and does stuff when I step away. I've been told that the Green/Red wire from the alt can go to either the wire that runs to the ALT light in the instrument cluster or the old "i" wire on the old Voltage Regulator plug. Your idea if using the yellow/green wires in the plug above seems to make sense though.
Only time it boosts power is during start. Only time it has 12v on the actual terminal itself is during start.
But the Brown wire has 12v any time the key is on because of a physical connection at the splice to the Red w/green ignition coil wire.
That’s why it can work in this situation, but just isn’t a reliable source.
Cool, thanks.
I know you said it before, but I wanted to make sure simply because most of our trucks ended up with ammeters as it seems.
Over the years I’ve only seen a couple with lights and only a few of the members here seem to have that set up.
Interestingly enough whether you had the light or the ammeter dictated how the alternator and regulator were wired. The regulator was wired completely differently between the two types of indicator.
My '79 did not have that type of setup. Are there any other wires going in to, or coming out of, that block? Looks a lot like a junction/splice cover, but since it goes to the battery side of the starter relay/solenoid it's likely the fusible link / charge wire from the old alternator like John89 said.
Since you're changing to a 3G anyway, why are all the old wires still laying around? I see the old alternator wires, which should be removed to get them out of harm's way and keep you from having a short later. Were you just waiting until the 3G was installed and verified working? I think it's easier to remove them while you're working, but that's just me.
I see that they're pretty faded. Seen that a lot, but not every truck suffers that fate.
If I remember the '76 has the regulator over on the core support rather than on the fender skirt? I know sometimes the wires are loomed up with other un-related wires, making it harder to remove the ones you don't need and leave the ones you do. But since this is a re-wire 101 kind of, it's only one more step to un-wrap the harness where you're working and get rid of un-needed and potentially trouble some wires and if you want, re-wrapping the leftover wires back up to clean things up and protect them for the long haul.
No matter what though, you do NOT want random wires attached to the battery so you really need to remove the end of the Blue wire attached to the battery side and unearth where the other end goes and if they are previous generation alternator wiring, get rid of them.
So follow them down, unwrap them if needed to see what color and where they go.
Why is there a Green wire (new one) on the "I" post of the starter relay?
Is the Yellow wire on the battery side for the sensing wire of the new 3G? Could the Green one be taking the place of the old Green w/red wire on the new 3G?
If so it's kind of in the wrong place. It'll likely work of course, but it's a finicky connection and can work loose over time with just that push-on connector to hold it in place. Leaving you with a no-charge situation at random times while driving around.
The original Green w/red wire is right there in that 2-wire connector above it and should have the same function of 12v with the key in the ON and START positions. If it's working, then it's the better choice I think.
In fact, you can clean up the starter relay/solenoid wiring by re-using that 2-wire plug. Simply use the existing wires (Yellow and Green) to handle the same functions as with the original alternator.
Having fun yet?
paul
Regarding that Blue wire, it's one of the 3 connectors that went to the back of the stock alternator (see picture below). We're working on getting the original harness out of the truck. Safe to assume that we can remove that wire as well? Thanks!
while I've never seen that connector with the two extra wires crimped to the Black wire, I'd have to say yes you remove it. It appears to be part of the three wires at the back of the old alternator, they are no longer used so must be removed.
You can always confirm any of this by following the wires to their other end termination. The large Black wire would have been on the larger BAT post of the back of the alternator, correct? If so the other end would have originally gone to the starter relay's battery side. So yes, remove and toss out. Along with the wires with the orange and black boots and the rubber "strain relief" molded around them.
In that molded strain relief however would also be the metal tab for the ground wire, which I think we've talked about previously. So there may be one additional wire to the old voltage regulator that get's removed as well.
And just so I'm on the same page, the large wire in our hand in the above pic is the end that was attached to the alternator. And the other end was that black splice with the Blue wire coming out of it. Correct?
And just so I'm on the same page, the large wire in our hand in the above pic is the end that was attached to the alternator. And the other end was that black splice with the Blue wire coming out of it. Correct?
Great. Sounds like you're good to go then.
Maybe those small secondary wires in the crimp are for the ammeter shunt. But I thought you said your truck has the light instead of the ammeter gauge. But I could be remembering that from another discussion entirely the way my mind works!
