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Discussion Starter · #1 ·
Questions regarding my ’79 and EZ wiring harness I’m installing (so you don’t have to read everything below):
1. What are each of the wires coming out of the instrument panel connector? I’m looking for color and function (and yes I’ve looked at the wiring diagram – it’s a little confusing – and done a search).
2. How do I hook up the idiot light and/or find a 510 ohm resistor to get my alternator working properly (i.e., what wires connect to the idiot light)?

Background:
I'm just about finished rewiring my ’79 with a kit I bought from EZ wiring. I upgraded to a 3g alternator (which I definitely need to wired better – that EZ kit doesn’t look like it will take 130 amps, even with the bypass wire) and Taurus fan while I was at it, but I have a question on the instrument cluster wiring. I’ve got gauges (ammeter, oil, fuel level, water temp), but I bypassed the oil, amp, and water temp, instead going with an aftermarket setup.

Anyway, the EZ kit has an ‘alternator exciter’ wire that is supposed to go to the ‘I’ terminal on the alternator. I hooked this up, and I AM getting 12.4 V in ‘Run’ at the connector. I hooked up the alternator as shown in the BC Bronco schematic (‘S’ terminal to stator, ‘A’ to ‘BAT’ terminal, ‘I’ to ‘alternator exciter’ wire). The ‘BAT’ terminal is hooked to the ‘Alternator power’ wire as instructed in the EZ manual, with the bypass going to the starter solenoid (again – I’m going to run a 4ga wire to the solenoid with a 175a maxi-fuse because the EZ wiring is MUCH too small). I bypassed the idiot light altogether. From what I’ve read, I need a 510 ohm resistor to make the alternator work properly. I did have it bench tested after I pulled it from the junkyard, and it tested good. So where and what colors are the idiot light wires, and what are each of the wires at the instrument cluster plug?
 

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You should not need the resister to run the 3G alternator. I converted my 79' (with gauges) over to the 3G and all I did was disconnect the regulator harness, ran 4 gauge wire from the alternator thru the 175 AMP fuse to the battery side of the stater relay. I did have to find a new location to plug the choke heater into and I found the voltage regulator harness had one socket that was 12 volts (normal off the alternator to the choke is 7 volts) so I plugged it in there. My dash gauge still works, as well as the voltmeter I put in. I don't trust AMP gauges as they don't give you a true indication of what you alternator is doing.

If you do a search for "3G alternator up grade", you will find numerous threads in dealing with this conversion.
 

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Discussion Starter · #3 ·
See, I completely rewired the truck. The original wiring had been burnt when it had a car-b-q, so I decided to get an EZ wiring kit. Now the alt won't put out any juice with the rig running, but tests fine on bench. I believe they sell a 510-ohm resistor on fordfuelinjection.com, so I may go that route.
 

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Discussion Starter · #5 ·
I've heard both sides of the argument. Some say you need a resistor and some say you don't. I bought a 2ga wire / mega fuse kit from RJM, so I figured I'd get the resistor you sell as well, Fireguy. We'll see how it works out when I get it up and running.

I do know that I had to add a resistor when swapping from the stock SI to a 105 amp CS alternator in my 71 Nova.

Granted, this schematic is for a 65 mustang, but it's the same basic setup. This mentiones the resistor.
 

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Discussion Starter · #7 ·
That's exactly what I was looking for - for some reason they pictures wouldn't load from autozone's website for me on my laptop, so I forgot all about those schematics. I've since downloaded 'em from a different computer and put them and a few other reference materials onto my photobucket account: http://s105.photobucket.com/albums/m235/hookemdevils22/Reference%20Matl/
 
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