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5/28/2013 7:16 AM  #1


66 mustang won't charge after efi swap

hi i did a efi swap out of a 88 mustang non maf i can't get it to charge. I started with the 2g alt no help switched to 3g still no charge if i excite the green/red wire going to alt an gauge the alt kicks in but no charge only jumps up a volt and alt starts sqeeling. installed original alt from 66 tested everything an still no charge when i rev engine it starts to pop out of intake. should i try a harness from rjm injection I'm at the end of my ropes and so is my wife any suggestions thanks

 

5/28/2013 10:45 AM  #2


Re: 66 mustang won't charge after efi swap

Have you tried the fordfuelinjection.com (now oldinjection.com) website? There are wiring diagrams there.

http://oldfuelinjection.com/?p=63


1965 Mustang 2+2 EFI
 

5/28/2013 11:02 AM  #3


Re: 66 mustang won't charge after efi swap

yes i got the diagrams off that site and as far as i can tell everything is wired correctly thanks

     Thread Starter
 

5/28/2013 1:11 PM  #4


Re: 66 mustang won't charge after efi swap

I don't know if there is any difference with EFI set up I would think not but you should have your have the red wire from large post on Alt to Batt. Looking at the at the rear of the Alt. 3 terminals. One to the right (Lt. Green/ Red) goes to 12 V + Key switched. Middle (Blk/Wht) short jumper to terminal on Alt. next to large Red wire.One on left (Yellow) goes to Battery + (could jmper to large Red wire) Check your grounds make sure you are not trying to ground through paint. You could measure resistance from the Alt. case to the Neg Batt terminal. It should read zero or very near zero. Take the Alt to the part store and have it tested.

Last edited by wsinsle (5/28/2013 1:12 PM)


If this forum can't fix it, it isn't broke.
 

5/28/2013 7:27 PM  #5


Re: 66 mustang won't charge after efi swap

Pretty hard to troubleshoot with no more information.  Specifically, how did you wire the charging circuit?  Did you use an aftermarket harness or do it from scratch?  does it look anything like this?  What is different?

http://oldfuelinjection.com/public/alternator/2G-ALT_wiring.gif


 

 

5/29/2013 5:33 AM  #6


Re: 66 mustang won't charge after efi swap

yeah i got all my info off oldfordinjection wirid 2g 3g and stock alt up (no charge) put on extra grounds even tried making grounds with jumper cables to different places still nothing when i excite alt with green wire it will charge 12.3 volts from 11.4 an thats it. engine starts to run poor man i'm confussed i got so much time in this i could of had car painted by now  my next thought is its drawing from efi somehow. I'm also using 66 ignition switch if this matters.

Last edited by troym28 (5/29/2013 6:25 AM)

     Thread Starter
 

5/29/2013 10:42 AM  #7


Re: 66 mustang won't charge after efi swap

Did you remove the 65 voltage regulator(by the radiator)?? The 2G and 3G alternators have volt regulators built into them. The 65 chassis isn't needed any more.
Are you using a PDB(Power Distribution Box)??

Corky
 


If it ain't broke, I haven't modified it Yet
 

5/29/2013 10:49 AM  #8


Re: 66 mustang won't charge after efi swap

yeah i unhooked it i think the problem may be i hooked pcm,tfi,and coil pwr wire key on pwr to the red wire coming out of ign switch which is a resistor wire so i need to cut out the resistor wire sound right?

     Thread Starter
 

5/29/2013 11:16 AM  #9


Re: 66 mustang won't charge after efi swap

That will send full voltage to te ignition, though I don't see it preventing the Alternator charging.
Is this occouring at idle only or have you checked it at 2000 RPM?? After 2k RPM the exciter isnt needed.

Corky


If it ain't broke, I haven't modified it Yet
 

5/29/2013 11:22 AM  #10


Re: 66 mustang won't charge after efi swap

no i havn't cause when alt is excited (energized) the engine pops through intake like it's predetinating

     Thread Starter
 

5/29/2013 12:49 PM  #11


Re: 66 mustang won't charge after efi swap

troym28 wrote:

yeah i got all my info off oldfordinjection wirid 2g 3g and stock alt up (no charge) put on extra grounds even tried making grounds with jumper cables to different places still nothing when i excite alt with green wire it will charge 12.3 volts from 11.4 an thats it. engine starts to run poor man i'm confussed i got so much time in this i could of had car painted by now  my next thought is its drawing from efi somehow. I'm also using 66 ignition switch if this matters.

 
The alternator should be putting out ~14.5 volts when charging.  Your measurement of 12.3 tells me there is something wrong with your charging system.  Take the alternator and battery to the parts store and have them check alternator charging and the regulator and the battery for charging.  My guess is that your battery is wounded and the alternator is sending most of its output to trying to charge the battery, leaving not enough for the ignition.

 

5/29/2013 2:24 PM  #12


Re: 66 mustang won't charge after efi swap

Try exciting the Alt with a fused jumper straight from the Battery.


If this forum can't fix it, it isn't broke.
 

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