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I am connecting up a new wiring loom in my 71 454 and I have an aftermarket alternator that I’m using until I can get a correct one. On the aftermarket one there is only a single spade connector and on the new loom there is a double plug. On the old loom the black wire with the white stripe was not connected. Can someone please explain what the consequence’s of leaving the black wire not connected please?
thanks.
Im in Australia for the people with eagle eyes FYI.
I am connecting up a new wiring loom in my 71 454 and I have an aftermarket alternator that I’m using until I can get a correct one. On the aftermarket one there is only a single spade connector and on the new loom there is a double plug. On the old loom the black wire with the white stripe was not connected. Can someone please explain what the consequence’s of leaving the black wire not connected please?
thanks.
Im in Australia for the people with eagle eyes FYI.
Doesn't your alternator have a slot on the edge for the double wire plug. That plug connects to the alternator regulator and field to energize the alternator.
Is that a 10si alternator?
The two wire plug is for the regulator on a Delco alternator. One wire is hot and the other is keyed power. In this situation all you need is the keyed power wire,
. I believe it is the black/white wire but that would be easy to test with a test light.
No it doesn’t have the double pug on the side to connect it. Just to the right of the double plug in the picture is the spade connector. Thanks
Then you don't have the original factory type 10si alternator.
I see it says Bosch but beyond that have no idea what it is comparable to. If previously it didn't use the wire you won't be able to using that alternator.
Does your ammeter work?
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Originally Posted by MelWff
Did you mean the B+?
The discussion concerns the 1 and 2 wire that plug normally into the regulator on a 10si alternator.
I agree, test the BROWN wire to see if you have 12 volts to it with the key ON.
If you do, then the brown wire connects to the terminal to the right of the two prong connector in your photo.
I am connecting up a new wiring loom in my 71 454 and I have an aftermarket alternator that I’m using until I can get a correct one. On the aftermarket one there is only a single spade connector and on the new loom there is a double plug. On the old loom the black wire with the white stripe was not connected. Can someone please explain what the consequence’s of leaving the black wire not connected please?
thanks.
Im in Australia for the people with eagle eyes FYI.
Not so easy in Australia and I need the 61amp for an a/c car. I’ll test the brown wire like the other guys suggested and hopefully that will work. Thanks for all the comments.
What part number is that Bosch alternator?
If it's anything new then it's probably a better alternator than that old 10si.
Tell us that part number and we can look around for it would take to adapt it to your car.
Originally Posted by Krafty36
Not so easy in Australia and I need the 61amp for an a/c car. I’ll test the brown wire like the other guys suggested and hopefully that will work. Thanks for all the comments.
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Originally Posted by carriljc
What part number is that Bosch alternator?
If it's anything new then it's probably a better alternator than that old 10si.
Tell us that part number and we can look around for it would take to adapt it to your car.
Good suggestion, if we can get a schematic, we can be sure that the empty terminal does connect to the sensing wire.
The D+ terminal is the "exciter" wire for a Bosch alternator and connects to the dashboard's charge warning light.
It works in two phases:
Initial excitation: When you turn the ignition key on, a small amount of current flows from the battery, through the warning light, and to the D+ terminal. This pre-energizes the alternator's field coil, allowing it to start generating power once the engine is running.
Warning light function: Once the engine starts and the alternator begins charging, it produces its own voltage at the D+ terminal. This causes the voltage on both sides of the warning light to equalize, and the light turns off, signaling that the system is charging correctly.
I checked and there is power to the brown wire when the key is on so AI have connected the brown wire to the D+ terminal and hopefully everything will be fine. Thanks for all the advice.
Yes it does which is great but something else is not quite right because when I turn the key to start it makes a boing sound and the starter doesn’t turn over.
Yes it does which is great but something else is not quite right because when I turn the key to start it makes a boing sound and the starter doesn’t turn over.
Did you recently replace the starter or have done anything related to the starter. Sounds like it needs shims.
Alternator wiring
