Maybe Altenator issue?? Need help

[Automan]

Hi Everyone, My 63 1/2 427 cobra from Antique and Collectible is having some power issues. So im driving and my alt-meter gauge shows 14 amps and in the green. When i turn on the cooling fans it drops alittle to about 12 amps. But if i turn on the headlights, amps drop to yellow and the engine seems to loose power. If i stop at the lights, the engine struggles to idle and the needle is in the red.

I have a new Battery installed, and the only other thing that i did was install a auto cooling fan and shroud from Summit Racing.

Any advice??
Thankyou
Nelson

[LMH]

14 Amps? Or volts?
Larry

[DanEC]

I think he means volts. At idle with the electric fan(s) running and the headlights on, I would not be surprised to show the voltage across the system to drop to 12 or lower. The load on the alternator might also pull the engine idle down somewhat. Blip the throttle and it should pick up to 14 volts immediately. You can probably raise your idle speed a little to counter this. Do you know what size alternator you're running? Possibly one with a little more amperage output could improve this considerably.

Another possibility would be to wire an idle speed solenoid in on the carb to raise the idle when the fan kicks on - but typically these solenoids are not powerful enough to push the throttle open without a blip of the throttle first. So, it may not be worth the effort.

[saltshaker]

I had a similar problem, I use a Mark Vlll fan which draws a lot of amps and solved it by running a #8 wire from the back of the alt to the batt side of the selenoid. Do you have a thermostat switch connected to the fan or is the fan always on ? ...that makes a difference too.
Jon

[427sharpe]

That is very low, assuming the alternator itself is in decent condition and not on deaths door. What alternator are you running? I presume the used-forever-1G that Ford used all thru the sixties and seventies? If so, you may consider changing over to a new style Ford 3G, which is the common alternator now for the electronically laden, fuel injected cars and will supply power out the wazoo for our simple machines. They come in 93 or 130 amps, internally regulated and a very simple DIY install. Even fits the same brackets if you mind the case sizes. Plenty of articles/info out there on the net (surf 'Ford 3G upgrade'). Wiring is a snap and 93 amps replaces 60 or so in about 20 minutes.

[427sharpe]

The green 'I' wire is ignition, of course.

[Automan]

I have a thermostat switch relay that i have it set to turn on at 200 degrees. I also have the dual pusher fans that i use manually. because its manual, i was able to turn them on when i turned the lights on on the highway and seen the needle drop to low yellow and almost red.

[Automan]

Im actually seeing the needle drop while i am running the car even on the highway. I have a 65 volt alternator that is seven years old.

[Automan]

65 amps alternator. early to mid sixties type

[jhv48]

There's the problem. Most cars have at least a 90-100 amp alternator. Yours can't keep up when all the accessories are on.
Fans alone can eat up 50 amps. Add the headlights and you're maxed out. Time to upgrade.

[MOTORHEAD]

re; low power, if you're running an ignition box and the voltage drops too low, it might cause the ign to cut out.

[Automan]

Yes, volts. Sorry

[slithering]

Hi Automan, If you are still experiencing your voltage / amperage issues, here are a few suggestions. Definitely upgrade your alternator to a 90 amp. with dc voltage, when there is a drop in voltage there is a drop in amperage and this is damaging all components. Your cooling fans need an independent ground going to frame.
I have a 427 sideoiler with a 4500 cfm cooling fan and a 90 amp alternator. My cooling fan is wired as it's own system with a 60 amp fuse and a 190 temp switch. I have no issues.