1965 alternator switch
 

The split rocker switch that controls the alternator allows the front alternator to be taken off line, and leave the rear alternator on line. However, it does not seem to allow the reciprocal function ( turn off the rear alternator and leave the front alternator on line) . Instead the right (rear) alternator switch turns both alternators off.

Any ideas on why this is?

Cheers!

Jerry

Is the rear alternator going off line because of over voltage?

Alternator switch
 

No, the rear alternator is doing just fine. The "Standby/Run" switch worked as advertised. The front alternator fell apart (literally) during approach to destination. I had not paid the alternator switch any real attention until then. I have now had my attention refocused. :cool:

During pre-flight run up I have a set of toggles and meters that measure either battery or alternator levels of charge/discharge, as long as the needles said charging and the load was equal, I was a happy guy. We didn't get into the mechanics of the actual alternator switches until it came time to shut stuff down.

At my maintenance base (KRBD) there are 4 vintage 1974/6 337s. I looked at each of those and my set up is very different from them. The other 337 are all either P337 or T337s with 38 amp or more alternators.


Jerry

Jerry:

What is the serial number of your plane? I will look at the wiring diagram.

Dave

I know just what you are talking about. Just got 4 new switches today and you can turn them both on, but can only turn the fwd one off but not just the rear without turning the fwd off too. I can see an easy fix by removing a small tab between the 2 switches
I plan to call Cessna and tell them about their blunder.

Cessna reason?
 

It would seem Cessna had a reason for this - but I can't think of it. You have me wondering about my '66 now. Will check it on the weekend.

Jeff

Follow up
 

Sorry for the delayed follow up. My '66 (337-0487) alternator switch can switch both on or off independently.

Jeff

1965 alternator switch
 

Hello. I have the same type switch for my MASTER on my 69 C172. The left side (Alternator) right (Battery) you can switch on the battery independently but with both on you try to turn off just alternator side both go off. I was wondering where the "TAB" is you are talking about removing? I'd like to do this modification as well??
BILLS

I think you could have a fuel pump switch instead alternator switch, cause the way you describe it works is as a fuel pump switch

My fuel pump switches are red and yellow. alternator switch is grey