Topic: Voltage Regulator - 1967 Convertible With Power Top and Without A/C

[196667Bob]

I firmly disagree. I have provided a significant amount of evidence that shows that only a 38 amp Alternator is required for the Power Top. I have seen no evidence that a 55 amp Alternator is required for the Power Top.

I believe that the shoe is on the other foot.

Bob

[67gtasanjose]

Occams razor:

SIMPLE way to check (if it ALSO hasn't been replaced).
What size battery tray do you have? 22F or 24F.

[midlife]

In all my years working on various Mustang harnesses, I have yet to run across a 20 gauge wire.  The smallest is 18 gauge, the usual is 16.  Power-hungry lines, such as wipers, horns, etc., are 14 gauge.  Power sources (ACC, battery) are 10-12 gauge.

[Bob Gaines]

I firmly disagree. I have provided a significant amount of evidence that shows that only a 38 amp Alternator is required for the Power Top. I have seen no evidence that a 55 amp Alternator is required for the Power Top.

I believe that the shoe is on the other foot.

Bob

Then I suppose we can at least agree to disagree .

[Bob Gaines]

In all my years working on various Mustang harnesses, I have yet to run across a 20 gauge wire.  The smallest is 18 gauge, the usual is 16.  Power-hungry lines, such as wipers, horns, etc., are 14 gauge.  Power sources (ACC, battery) are 10-12 gauge.

Your missing the point . Regardless of the gauge of the A/C wire it is obvious (isn't it?) that the power top feed wire is a heavier gauge wire which logically indicates it carried a heavier load.

[rodster]

SIMPLE way to check (if it ALSO hasn't been replaced).
What size battery tray do you have? 22F or 24F.

FWIW, I have factory AC, COMBINED with a different anomaly...my Marti Report doesn't list H.D. Battery option AND I had (yes, I said "had") a "dated correct" 22F battery tray in it.
Research at this forum has convinced me that my example OUGHT TO HAVE BEEN BUILT with the 24F battery and 55 amp alternator and certainly it makes better sense to have MORE amperage available than LESS amperage. I updated my battery tray. After all, it ALSO relieved me of hunting down a 22F battery that is essentially unobtainable.

Dependent on engine size?

[midlife]

Your missing the point . Regardless of the gauge of the A/C wire it is obvious (isn't it?) that the power top feed wire is a heavier gauge wire which logically indicates it carried a heavier load.

True.  The current need of the power top is probably on the order of 10 amps, so a 20 amp circuit breaker would be called for (a safety factor of 2 is what I find Ford liked to use).  Nevertheless, a 10-15 amp draw for 30 seconds doesn't require a larger alternator as the battery itself can handle that short-time draw.  The alternator is there for recharging the battery, not for primary electrical current draw.

[Bossbill]

I tend to think that A/C cars would require a better battery/alternator due to heat soak, not that A/C required those parts or electrical energy to run. Heat soak would cause the starting system to have to work much harder.

[CharlesTurner]

Previous discussion regarding alternator ratings...

https://www.concoursmustang.com/forum/index.php?topic=19345.0

[mtinkham]

Maybe the wire size is also considering the length of the wire run?