Alternator help

[TooManyFords]

After the carcraft show, it appears my alternator has taken ill, along with the factory PCM. The PCM spontaneously reboots causing the transmission to go into neutral and then find the correct gear. The Alternator on the Marauder is also controlled by the PCM to tell it when to charge and when not to. With the PCM crapping out, I believe the alternator is not being told to charge the battery, and the regulator is toast as well.

I am switching the car over to run without the PCM and have already installed the BigStuff3 engine management PCM. That works great. The Turbo 400 tranny goes in next week, and that should eliminate the old PCM from the drive train. However, I need help in wiring the Alternator so that it will work without a factory PCM to drive it.

I have a new regulator for the 03 Cobra (grey one) to replace the white one on the alternator. The question I have is, which wire in the three-prong plug needs to get switched 12+ to tell it to alway put a charge out?
In other words, I want to make it work like the old days...

Does anyone have a wiring diagram of the charging circuit of the 03 Cobra from the Ford Manual showing the regulator they can scan and post?

Thanks.

John

[KillJoy]

:dunno:

I dunno.... BUT, pickles are green.

:D

KillJoy

[MM_BKK]

Try these:

I believe pin# 3 gets +12V to tell it to start charging.

[TooManyFords]

MM_BKK, I have the Red Book for the electrical for the Marauder. While studying the charging system (as you posted), it appears that pins 1 and 2 also play into getting the alternator to begin charging. This is how the PCM can disable the alternator during WOT, by pulling power to either/both (?) pins, but it is not clear from the chart which one does what.

This is why I ordered the regulator for the 03 Cobra, the Grey Regulator. Supposedly, this one is not computer controlled but senses the +12 line and figures it out. Why it also has 3 pins is still a mystery but I am going to figure this out.

My goal is to completely remove the old harness and the PCM since don't use it to manage the engine or trans. I do have to figure out this charging thing though or the battery will not stay charged.

I supposed I could just check the pins on the regulator connector to see which ones have +12 when the key in in the run position. Then, depending on what the grey Regulator requires, just modify the current connector and plug it in.

If no-one has the Grey Regulator charging system diagram, I may have to wait till Tuesday and go look at the book at the Ford service department to see what it says. If so, I'll be sure to share so others can benefit from my learing experiences.

John

[FordNut]

Does this help?

[TooManyFords]

That was exactly what I needed. The way I read the wiring diagrams, the grey regulator should always be in a charge mode since it ignores pin 2. If I want to bypass the PCM control, I should only have to pull pins 45, 7 and 70 from the PCM plug and cross 7 to 70 to make the battery light work. Since I don't need a battery light with a true voltmeter, I think I can leave 7 and 70 disconnected. For the test though, I'll just disconnect pins 1 and 2 at the alternator plug just to test for charging.

My only remaining question is about the Stator feedback, whether it can be left disconnected. I am assuming that the regulator has an internal circuit to monitor the voltage at pin 3 to know when it needs to cut back.

Thanks Brian.

[TooManyFords]

And a a follow-up...

I replaced the white regulator with the grey one after having cleaned the shaft with emery paper, and it does indeed charge the battery while running. 14.5 volts to the batter at all times. I did not pull any pins and wanted to see what would happen if I didn't.

Now to hook up the rest of the Nexus gauges so I watch the volt meter while driving.

Still have that problem with the PCM resetting and I'm going to get some wire taps to see if one of the +12 volt lines into the PCM has a break in it.

Off to Radio Shack...

[TooManyFords]

Oh, and another useless piece of trivia...

If you want to change the alternator without removing the water cross-over tube, you need to remove the water pump pulley and the Alternator pulley (if it has the clutch). If it doesn't have a clutch pulley it will come out without removing it. I know for a FACT you cannot put it back in WITH the clutch pulley attached beforehand.

Also, if you have the clutch pulley and want to remove it before reinstalling, I took a 1/2" drive socket that was slightly loose in the tooth area of the pulley, wrapped the socked with electrical tape till it was a snug fit, and then hit it with the air wrench. Spun right back off.

Before putting the clutch pulley back on, put a dab of anti-seize on the threads for future upgrades.

[Zack]

John, your crossover tube is 1.25" shorter than stock, so this info only applies to you :rolleyes:
How soon you forget what mods your car has :D

[TooManyFords]

John, your crossover tube is 1.25" shorter than stock, so this info only applies to you :rolleyes:
How soon you forget what mods your car has :D

D'oh!


:P:P