Re: Question about elecromatic option

Posted by HH56 On 2017/1/2 21:55:28

That switch at the end of steering column looks to be the combination reverse light, OD safety switch. I can't tell how many terminals are in the broken off portion. It looks like the large switch so if it has 4 terminals, one set of terminals (pair distant from plunger) would work the the reverse light. The pair closest to plunger was a safety disconnect switch used on early 48 cars that had an R9 overdrive.

The R9 OD used in the early part of 48 production had a lockup issue that was partially corrected by adding a forced disconnect of power to the OD when shifting into reverse. The function was part of the reverse light switch, or since the light was an option, the safety portion alone could be used. The R9 was superseded by the R11 overdrive and when the R11 went into production there was no further need for the safety switch. Most switches reverted back to a smaller switch with 2 terminals for the reverse light only. The larger switch could still be used for reverse light only and, on a lot of cars the R9 was field changed to the R11 and the original switch stayed.

If you have an OD look at the relay on the firewall for an easy way to identify. If it is an R9 there will be a large black almost square relay about the size of the voltage regulator. It will have 6 terminals. If an R11, the relay will be a smaller rectangle with 4 terminals and a fuse on the side.