VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 Polarity Reversing Switch

My foot starter does not have a polarity reversing switch,so I purchessed one and with the starter boxed up never thought to check it out for the switches future instalation,when I unpacked the starter I found there were no mounting holes for the switch????I am to understand these switches were used on 41-48's???So I guess I have 3 options drill the 3 holes (being careful to properly line it up)Find one with holes or the switch already on it or as before go without????chef-

Starters are not that expensive. I would search for a Delco-Remy 1107061 or 1107055. It is obvious you do not have the correct starter.

One problem we all experience with starters and generators is that the old repair shops immediately removed the data tag from all the "cores" they received. They were retagged with their own badge or just painted on, new numbers. By doing this they were able to reduce the number of different items in their inventory. As you have noted many items will "work" but may not be "correct".

In layman terms,what exactly does the polarity reversing switch do?and what years cars did not use them ,seeings how the Chevy starter changed in 1949 chef-

The idea behind the reversing switch was to reverse the flow of current through the points each time the car was started. By reversing the flow it would cancel out the transfer of material from one side of the points to the other. (If you were to examine a set of points that had operated for years on a car without the reversing switch you would note a "spur" on one point with a corresponding "crater" on the other point. This makes it next to impossible to check and adjust the point gap.

This system was used from 1941 through 1948. Perhaps the reason for the discontinuance was the problems associated with the additional mechanical movement in addition to requiring a special distributor. The special distributor had an insulated point plate and became one side of the special circuit. There is no argument that the system improved the problem it was designed to correct, however at a cost of reliability to the overall system.

Only the early 1948s had a reversing switch.The were discontinued around April 1948.That is why your starter has no holes for one.If you car was an early model it will have a distributor with the curved points and the distributor plate will measure 2 13/16".The late cars have a 3" dist. plate and uses the same points as a 1934-40 and 1949-52.The stationary arm is straight.

After checking the #on my starter I found 1107009,which in the parts book refers to 1938-1940,a stock starter but wrong year,I've searched for the 41-48 including G&D with no luck yet I will measure the distributor plate to assure it is the 3" one and reinstall existing starter until I find the starter-distributor combo....Some interesting stuff..What will I find next..chef-

Do you know the approximate production date of your car?If its after March 1948 it will not have had the reversing switch.Actually the majority of 1948s did not have one.I always remember the mechanics coming up to the parts counter and asking for points for a 1948 and they would say if it had the srtaight (non reversing switch) points or the curved points.The curved were part no. 1882391 and the straight were 1855720.The info. is in the March 1948 Chevrolet Service News.For some reason that issue of mine is missing right now.This is not mentioned in the 1948 parts book that I have.

The 1949-54 truck starter will also be a correct replacement for your '48.Should be an 1107055-thats the number from a 1952 parts book.Its listed for 1938-48 cars plus the trucks - all thru the 6 volt years.If your present starter is working OK you could purchase a new tag and re-stamp it

ChevNut is the 49-54 truck starter without a reversing switch???..chef-

Yes, Nothing had a reversing switch after early 1948.

A reversing switch can not be added to a car that did not originally have one.To do so the correct distributor and wiring harness for the switch would be necessary.The rev. switch distributor can be changed to eleminate the rev. switch but the non- rev. switch dist. can't be changed to use the switch.Most cars had the switch removed or disconnected by the time that they were a few years old as they were troublesome.Thats why Chevrolet gave up and discontinued them in 1948.

although I'm sure my distributor is non-reversing,is point replacement the only thing needed to be done to change the distributor to the non-reversing type??chef-

Chef, I would think that the distributor plate, if not the entire distributor, would have to be replaced as the points would not be directly connected to ground but would be insulated above ground.

It's not too hard to drill holes for the reversing switch. As you indicate, one needs to be careful but I doubt that you will have any problem with it.
By the way, my 42 didn't have the distributer for the reversing switch and I had no problem locating one. The other distributers can be purchased from some auto parts stores.

More than you want to know on reversing switches.

This switch was first used on the 1941 vehicles. When starter 1107033 was installed the kit was part number 1884827. During the 1941 run the starter was changed to 1107054. In the early application the actuating rod was round. When the new unit was used the actuating rod was flat. In 1946 the kit carried part number 1907122. As has been mentioned earlier the switch was discontinued during the 1948 run.

The distributor used in ALL of these applications was the 1110090. The two insulated contact bolts directly opposite each other easily identify this distributor. The coil is attached to one of these terminals and the reversing switch wiring harness was attached to the other terminal.

There is very little, if any, difference in the operation of the engine if the reversing switch is or is not used. However, without modifying a starter only 1107033 and 1107054, have the predrilled and tapped holes to mount the switch.

As to the distributor, the 1110090 may be used with or without the reversing switch. If used without the reversing switch the rear terminal on the distributor is wired to ground.

See CSN (Chevrolet Service News) October 1948 for specific method to change from the use of the switch to the elimination of it.

As to the use of the above information it is chef-chevy's call. He must decide if he wants it installed or removed.

Great info,Chevy worked real hard trying to inprove the products.I will keep searching for the correct parts..chef-

Although my distributor does not have an ID tag(or holes for one?)the # 0n the plate is 1112353,the closest I find to this # is 1112358-1953-1957.What should this tell me if any thing..the plate does measure 3" though...chef-

1112353 is the distributor number.It is the late 1948-49-50 216 distributor.The early 1948s had dist. #1110090.This indictaes that your car never had a reversing switch.

Were off to the 6 Cyl. Tour in New Jersey this morning.When I get back I want to hear it run

Gene unfortunately I,ve been spending most all my spare time building the garage for the 48 instead of working on the car itself.I will not make any deadline commitments I've broke too many already.It will have a real nice new place to live though,that is if I don't break the bank...have a great tour..chef-