[EvilPuppet]

Hi all,
It appears that my alternator is acting up a bit and not charging my battery enough.
I have measured voltage while the car is running and it reads 12.67 volts. Now I should mention that I have upgraded to electric fan, electric high flow fuel pump and MSD ignition. Previous owner had the Fan hooked up directly so it starts with the car (no thermostat yet). Then I tried disconnecting the fan and the voltage jumps to 13.07 volts.
At this point, I rev the engine to about 2000 RPM and the voltage jumps to 13.68 Volts.

I am running GM 1 wire alternator (my external voltage regulator has been removed from the car). I do not know what is the AMP rating for it.

What do you guys recommend? What amperage would I need to properly run Elec. fan, High flow Elect. Fuel Pump MSD Ignition And Radio/CD player?
Thanks
Alex

[jr.fullenwider]

The amps should be stamped on your alt casing, it sounds like it's probly a 65 amp alt i definetly would go larger.

[EvilPuppet]

Thanks for your reply . I had taken alternator off but could not see anything stamped on it. I agree with you. I also think it's about 65 amps.
Do you think 100 amps alt will be enough or should i go to 130-150 range?

[jr.fullenwider]

I think 100 would do but more wont hurt, just the wallet.I almost forgot but those one wire gm alts charge weak notoriously at idle. You need to rev the motor to ignight the charging right after start up just a lil throttle blip will do?

[Faith No More]

Why'd you replace the factory alternator [or standard replacement option] with a GM Alternator? Just curious haha.

My mustang had a similar problem, but it was the external regulator causing the issue, so i can't really help, my apologies.

[EvilPuppet]

No need for apology. I did not change it myself , previous owner did. I just have this car for 1 month now. Maybe going back to original would not hurt either. I think I will try 100 Amps 1 wire GM first and if that does not work ill go to ford 3g 130 Amps from Taurus or something similar.

Thanks both for your help...jr. you are right. When I start the engine it goes even below 12. Once the rpm is increased it jumps to 12.65 V and stays there.
I will report the results with 100 Amps just in case somebody else runs into these issues.
Alex

[Jonk67]

In order to correctly gauge how many amps you need you would need to know the draw of each non stock item -electric fan, ign.,f.p., etc. Stock survived with 55-65A so you would obviously need more. If you are changing I would say 100A would be the min. I would put back in, just as an example here my post where I installed a 100A Ford alt. that uses most of my original wiring and VR.
http://www.allfordmustangs.com/forum...lternator.html
Jon

[EvilPuppet]

Originally Posted by Jonk67

In order to correctly gauge how many amps you need you would need to know the draw of each non stock item -electric fan, ign.,f.p., etc. Stock survived with 55-65A so you would obviously need more. If you are changing I would say 100A would be the min. I would put back in, just as an example here my post where I installed a 100A Ford alt. that uses most of my original wiring and VR.
http://www.allfordmustangs.com/forum...lternator.html
Jon

Thanks Jon,
See my issue is that previous owner removed the VR and all junction points and wires needed for the original External VR and Ford Alt to work.
So before i go back to that setup I will try another GM Alt.
I picked up this 100 amp alt yesterday for 25 CND. It's brand new.

Now this Alt in addition to the main Bat connector has 4 additional connections on the side.
I tried to connect only bat connection but it did not charge. I probably need to connect some of those other connectors. The model is delco remy cs-130. Any suggestions?

Did your alternator come from Taurus?

[EvilPuppet]

I found the circuit diagram explaining connections from the alt to the battery

[The Greek]

I'm using a Power Master one wire 100 AMP alt. I have a Flex a Lite electric fan for the engine and a Hayden electric fan for the trans cooling a Holley blue fuel pump and Halogen headlights. All that I had to do is disconnect the original voltage regulator.

The alt output wire is connected to the battery side of the starter solenoid. I have 1/0 wire leading to the trunk mounted battery. With all of the electricals in use, it still produces above 13 volts. It is not a GM alternator that's been modified. I've never had a problem. You just have to remember to stab the throttle to turn it on.

[EvilPuppet]

Thanks Greek.
I just finished installing this alt and now I get 14.29 V with(or without) all of my accessories running. I had to connect little bulb to L connector on the alt and it started charging immediately. Since 66 does not have battery charging lite in the dash I will replace this bulb with 500 ohm resistor and that should do the permanent trick.
Another words it's perfect .
Thank you all for your help.