I just purchased, on Ebay, what I hope is a correct cut out switch for my '34 Standard. It is a Delco-Remy and the original box it came in has the following number on it: 1867781 Looking at my parts catalog I see part number 827843 for most '29 - '39 cars. Any ideas or information on the two above numbers would be greatly appreciated.

1867781 is a generator cut-out for a 1929-1938 in the later parts books

Chevgene,

Thanks for the reply. I feel a bit better as I thought maybe I still had an incorrect one. Is the number change typical for other parts in newer books? My parts book is for 1929-1942, effective March 2, 1942.

Lets say its no unusual for numbers to change when a part is used for that many model years. It generally indicates an improvement was made and that required a new number.
I worked in a Chevrolet parts department for 27 years beginning in 1950 and number changes were always a pain in the neck.

I am installing the correct Delco-Remy cut out switch on my '34 generator. Do I need to polarize the generator again? If so, am I correct that after it is wired up, I momentarily connect the two terminals on the cut out switch? Thanks for any replies!

Yes and Yes.

Most likely you will not need to polarize the generator as it should retain the polarization. You may find you need to adjust the cutout per the instructions in the Repair Manual. I find it is best to remove the cover, start the engine and then as you increase the engine speed notice if the electromagnet pulls down the upper point arm as the speed is increased and then keeps it down when back to idle. If so then all is well. If the arm does not get pulled down then manually push it down. Does it stay down both at higher speed and at idle? If so the generator is operating but the points may need to be closer together. If the points don't stay down in either case then quickly jump around the cutout. Just touch the contacts briefly. That will polarize the generator (if necessary). Then if the points don't pull together check out the cutout as it needs help. It is just a switch activated when the output from the generator is enough to activate the electromagnet. It opens when the generator no longer produces enough power to the magnet.

It only takes two seconds to polarize the generator so it is always a good idea to re-polarize the generator when any changes are made....including installing a new cut-out. Learned that the hard way.

Thanks guys for the replies!

It only takes two seconds if you already have the jumper wire in your hands and are leaning over the fender. If you have to find a wire, then a remove some insulation and then open the hood, etc. two seconds might be a bit of an optimistic prediction. If the gremlins are involved then there is no telling how long it may take.

You are right Chipper, those gremlins cannot be trusted.
Tony

Actually, it probably takes less than two seconds to strike an arc between the two cut-out posts. But, I guess Chippy Dippy if you are that disorganized to do a two second job.....then ya.....it would take way more than two seconds to do the polarization. Maybe even half a day in your case.