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DC power alternator not charging above 12v

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Old 10-16-22, 06:46 PM
  #26  
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Originally Posted by rx72c
S5 and FD have the SAME CONNECTOR but are NOT wired the same

That would have been your PROBLEM.

S5 and FD needs the wire pin positions reversed to switch between each other.
News to me... Maybe that's an Aus spec thing. I just checked our wiring diagrams, and both L wires are in the same spot, and even use the same color. That also, by default means that the S wire is in the same spot... And the B wire is just the B wire.
Old 10-10-23, 06:41 PM
  #27  
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Originally Posted by MIDNFauciUSN
I'll skip the boring stuff, and suggest that you wire the L terminal to 12V with an 12v bulb placed inline.

If that circuit has failed somewhere in the dash, it will cause exactly what you're mentioning.
I'm am having the exact same issue, at this point am completely stumped.
I'm running an Elite 1500 and was told by Anthony at DC Power that I had to run a 470Ohm 0.5W resistor in line with the 12V switches source, going to the L terminal. I am still not getting the alternator to charge past 12V. Battery is slowly draining below that. Right now, I'm getting that 12V from the 12V switched wire that is also powering my ECU. I have tested, and that wire is indeed getting 12V at the alternator. I even got a power probe and sent 12V straight to the L pin on the alternator. Zero change in voltage readings on the alternator lug. I'm thinking tomorrow I'll change the resistor in there for an incandescent bulb, just to try that out. At my wits end with this, as I have my mate from Australia coming to visit in a week, and was hoping to have the car running by then.

Another issue I'm getting is, NSP will completely lose signal from the ECU when the car starts. One thing at a time here though...



Old 10-11-23, 11:34 AM
  #28  
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If you connect 12V to that terminal without an in-line load, you *might* fry something. That terminal provides a ground when the alternator isn't functioning, so applying 12v to it would be a straight short.

Also, depending on the bulb, if you install a .5 watt resistor in parallel with the bulb, that resistor may fry. That's why I ended up going with a 5 watt. If you don't use the bulb, the math says that a .5W resistor is fine, but you wont have the easy visual indication that the alternator is working.
Old 10-11-23, 08:50 PM
  #29  
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Originally Posted by MIDNFauciUSN
If you connect 12V to that terminal without an in-line load, you *might* fry something. That terminal provides a ground when the alternator isn't functioning, so applying 12v to it would be a straight short.

Also, depending on the bulb, if you install a .5 watt resistor in parallel with the bulb, that resistor may fry. That's why I ended up going with a 5 watt. If you don't use the bulb, the math says that a .5W resistor is fine, but you wont have the easy visual indication that the alternator is working.
Thanks for taking the time to respond mate. I went through the trouble of wire wheeling off some of the anodizing around the Franklin Motorsports alternator relocation bracket. Tested resistance from the alternator cage to my star grounding point and got 0 Ohms. Figured this meant the alternator was grounding well enough, but I ended up running a new ground cable from the cage and now I'm getting a rock solid 14.5V.
what an absolute nightmare. 2 days doing that ****. You'd think they would have a better solution considering the alternator apparently doesn't ground through the bracket, but we figured it out eventually.
Also found my source of EMI...

The following 2 users liked this post by FC Australia:
rlynchster (10-12-23), scotty305 (10-12-23)
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