72 C3 wiring loom question
Thread Starter
Heel & Toe
Joined: Apr 2017
Posts: 24
Likes: 1
From: Auckland
72 C3 wiring loom question
My car suddenly stopped the other day and after finally tracking the fault, which turned out to be a blown wiper fuse. The issue here is that a previous owner replaced the standard coil with a Flame Thrower coil which required 12 volts. This resulted in a wire spliced into the 12 volt wiper feed, as the ballast resist original wire was not suitable.
The question is "is this the correct 12 volt feed, or is there a better solution"?
The question is "is this the correct 12 volt feed, or is there a better solution"?
Race Director
Joined: Apr 2011
Posts: 11,183
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From: North of Toronto - Ontario
I'm actually surprised that worked at all.
The original 12v feed from the starter must still be in place then as you need power during cranking and running and the wiper circuit (I believe) turns off during cranking.
If the original feed to the starter is there then any 12v source that's powered when the key is in the run position would work, power window relay is there, wiper is there as you know, etc.
During my conversion to MSD I ran a separate power wire all the way to the fuse box as I didn't want to rely on an existing circuit
M
The original 12v feed from the starter must still be in place then as you need power during cranking and running and the wiper circuit (I believe) turns off during cranking.
If the original feed to the starter is there then any 12v source that's powered when the key is in the run position would work, power window relay is there, wiper is there as you know, etc.
During my conversion to MSD I ran a separate power wire all the way to the fuse box as I didn't want to rely on an existing circuit
M
Thread Starter
Heel & Toe
Joined: Apr 2017
Posts: 24
Likes: 1
From: Auckland
Hi Mooser, many thanks for your reply. I forgot to mention, that we spent some time tracing back the wiring loom, according to the wiring diagrams that I have and there is a feed direct to the coil from the starter motor, so the car would fire on the start mode, but would not stay running on the run mode, if you can understand me. And that is what was initially puzzling me. If we ran a 12 volt feed direct to the coil, it would run. It was at this stage that I traced back the wiring from the coil, only to find out the modification.
We never stop learning (and by the way, this forum is a great teacher), and I now know more about my car, I carry a spare fuse or two, plus a jumper wire, should it happen again. My intention is to buy a new engine bay loom and return the car to its original setup and replace the Flamethrower coil with a standard coil wired up to the ballast resist wire.
Many thanks for your reply. Paul
We never stop learning (and by the way, this forum is a great teacher), and I now know more about my car, I carry a spare fuse or two, plus a jumper wire, should it happen again. My intention is to buy a new engine bay loom and return the car to its original setup and replace the Flamethrower coil with a standard coil wired up to the ballast resist wire.
Many thanks for your reply. Paul
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you could also replace the fuse with a circuit breaker so it would reset itself after a few minutes but that may be a bandaid to why its blowing.
I had a HEI system wired that way when I got my car and ended up running a stand alone wire for the HEI from the fuse block ign spade.
I went back to a stock coil setup with a pertronix breakerlesss system and love it. I like that look of originality. I have to modify my cold air intake to mount the stock shielding which is a few projects done the road this winter.
Good luck, hopefully you'll have it sorted soon
I had a HEI system wired that way when I got my car and ended up running a stand alone wire for the HEI from the fuse block ign spade.
I went back to a stock coil setup with a pertronix breakerlesss system and love it. I like that look of originality. I have to modify my cold air intake to mount the stock shielding which is a few projects done the road this winter.
Good luck, hopefully you'll have it sorted soon
