Blown88GT
Founding Member
That disconnects the electric clutch from the compressor, therefore compressor is free wheeling.I took that connector off and put the AC on it didn't turn off but the AC wasn't cold
That disconnects the electric clutch from the compressor, therefore compressor is free wheeling.I took that connector off and put the AC on it didn't turn off but the AC wasn't cold
That disconnects the electric clutch from the compressor, therefore compressor is free wheel
Good point. A bad battery could add to the current draw. Battery cells can short internally & the alternator attempts to charge a battery which won't charge. BTW, charged battery measures 12.6 VDC, each cell is 2.1V * 6 cells = 12.6VNo where here have I seen a battery test. I don't know what effects a bad battery would have on amp readings but I would have it checked anyway just to rule it out if you have not done so.
i don't have much faith in parts store testing procedures, they are not mechanics, they mean well but lack the training for complete diagnostic procedures. A high amp draw at idle would be a red flag to me and would need further investigation. That may be causing or at least contributing to your problem.
At 13V, battery is not being drained, but alternator is having a problem keeping up with the load.I have a similar issue/thread, but mine is a little more hectic....Most recent tests show that when my AC, headlights, and rear defrost are on it drains my battery from 14.5 volts at idle to below 13volts into an ugly stall.
Curious what the correct amp draw and voltage drop with the AC at idle should be? I am dumping power and amps somewhere. Its exactly the same results just the AC and the headlights on. How are you measuring amp draw?
Unfortunately, I do not have a clamp on AMP meter. Debating purchasing a cheap on to monitor amperage draw...
I always thought any voltage over 12V's should keep an engine running without flaw, but mine seems to die any time the battery voltage drops below 13V at the battery. I think the main power at the coil/ICM is less than main battery voltage. Mine typically measures ~0.1-0.5 less than main battery voltage.
Running the front defrost will require the AC clutch to engage. Sometimes during cold mornings I require front and rear defrost to be on. I agree though rear defrost isn't normally needed. I just turn it on to simulate heavy battery draw. I experience the same results with just the AC and headlights on (just takes longer).
Sorry, didn't mean to hi-jack the original thread...Seems like we might be battling a similar beast. :/
@michaelgt
Current draws with everything on: This is why a 3G alternator should have been standard equipment on all Fox body EFI cars.
Ignition system & computer = 12 amps
Fuel pump = 12 amps
Exterior lights = 15 amps
Fan (heater or A/C) = 15 amps (can run between 5-25 amps depending on setting)
Radio & instruments = 10 amps
Wipers = 10 amps
Rear window defroster = 5 amps (optional, not found on most southern fox mustangs unless the car moved down with the snowbird owner…)
That's grand total of 79 amps from a 65 amp alternator. Talk about overdrawn at the bank!
Full charge voltage for the battery is 14.2-14.5 volts with the engine running at 1200 RPM.
Full charge for the battery with the engine and all accessories turned off is 13.6-13.8 volts.
For more information see www.batteryuniversity.com/
DC clamp meters aren't cheap. AC clamp meters are.Unfortunately, I do not have a clamp on AMP meter. Debating purchasing a cheap on to monitor amperage draw...
I always thought any voltage over 12V's should keep an engine running without flaw, but mine seems to die any time the battery voltage drops below 13V at the battery. I think the main power at the coil/ICM is less than main battery voltage. Mine typically measures ~0.1-0.5 less than main battery voltage.
Running the front defrost will require the AC clutch to engage. Sometimes during cold mornings I require front and rear defrost to be on. I agree though rear defrost isn't normally needed. I just turn it on to simulate heavy battery draw. I experience the same results with just the AC and headlights on (just takes longer).
Sorry, didn't mean to hi-jack the original thread...Seems like we might be battling a similar beast. :/
maybe could have been but all I know that it's working now with the 19 injectors lolMaybe they were low impedance injectors?