HA;

Reverse switch senses reverse gear and supplies ground to pick relay controlling backing lights...4th gear switch senses that gear and is used in OD control circuit...and never the twain (circuits) shall meet!!

Item 41 switch 662292-2 Source: GCP's site.


...as far as using the reverse switch...I suppose you could, in the inverse...that is, when in reverse gear, with soma additional circuitry, you could DISSABLE the OD circuit to ASSURE that you did not go into OD while gearbox output shaft was turning the "wrong" direction (factory circuit does not do this...it doesn't need to use the reverse gear switch in the inverse logic mode when it uses the 4th gear switch in the positive logic mode)...but if you were to use the reverse gear switch in that way, that still doesn't allow OD only in 4th gear...other than adding the later sequencing relay to prevent "unwanted reactivation", I just don't see any good reason to start changing the circuit...my recomendation is install the above switch to sens 4th gear, and otherwise wire the OD control circuit with one of the circuits shown in article: http://sw-em.com/OD_Retrofitting.htm#Wiring_of_the_OD

I prefer Bavarian Erdinger Weissbier!

Cheers