Alternator

[Bulldog]

Guys thinking g about changing my alternator to a 75 amp car has a 60 unit now.Will 92 classic roadster wiring handle this size alternator? Bulldog.

[spdbrake]

You should be fine as the alternator only produces what the system demands of it.

This article on Amp ratings and data plate markings is helpful.
https://www.lifewire.com/understandi...ratings-534785

[Ron61]

I used a 100 Amp Alternator in my Classic Roadster for years and never had any problems. As stated above, the alternator just puts out what is needed and doesn't run at full capacity much of the time if any.

Ron

[Bulldog]

Thanks guys just what I needed to know

[BAsque1]

Try these guys





Ford Alternators

This is a single wire connection they are fabulous.

[bobcowan]

Yes, the alternator will only produce what is needed. But if you need to upgrade to 75A, then you must have a need for that many amps. If it was only going to produce 50A, then that's all you need and what would be the point of the "upgrade"?

So, going on the assumption that you need 70-75A, you might need to upgrade the wiring. You'll need to look at what you have already, compare it to an ampacity chart, and go from there. https://www.cerrowire.com/ampacity-charts

If you need more wire, you can either remove the present wire and add the proper size, or add a second wire. A Painless harness has two wires. You connect the second one if you're using a high amp alternator.

[cycleguy55]

Originally Posted by BAsque1

Try these guys





Ford Alternators

This is a single wire connection they are fabulous.

One-wire alternators have one benefit - they're easier to wire. Beyond that three-wire alternators are superior. Here's a good comparison: Catalog

I'll also reinforce the notion that wiring should be looked at when upgrading alternators. Existing wiring may have worked just fine for the 60 amp alternator, but may have been 'just okay' or marginal. Put a 75 amp alternator in there and marginal may become under-sized. While it's true the alternator will only output what's necessary, what happens in a scenario when you run the battery down and perhaps get a push or jump-start? The alternator then produces full output while trying to re-charge the low battery and that could become a problem if the wiring isn't up to the task. Better safe than sorry.

[RockBit]

x2 on the three wire alternator.