3 lever blackout switch

Bretto · Post by **Bretto** » Wed Mar 02, 2011 12:36 pm

Can a stock M38 3 lever BO switch be used in a 12v conversion? Or is there going to so trouble with the panel bright/dim portion with resistance?

toojeeps · Post by **toojeeps** » Wed Mar 02, 2011 12:44 pm

It can be used, but mine only works on the bright setting.

Bretto · Post by **Bretto** » Wed Mar 02, 2011 2:02 pm

Having not knowing how the switch fully works, I found and copied and pasted for you the following. If this is not correct, I'd like to know.

With the top lever in off: nothing

top lever in stop light: brake lights only

top lever in ser drive: head lights, tail lights and brake lights

leave top lever in ser drive and move bottom left lever to park: headlights off, front parking lights come on, tail lights and brake lights

move bottom left lever to left of off to 1st or 2nd position for dim or brighter dash lights, front park lights go off and headlights come back on

move top lever to left of off position for b/o marker: only lights on are bottom parts of front and rear (cat eyes)

move top lever left further to b/o drive: cat eyes on plus left side b/o driving light

Post by **wesk** » Wed Mar 02, 2011 11:32 pm

First off verify which light switch you have. There were several used. They appeared in this order.
Bendix-Scintilla two plug.
Bendix-Scintilla one plug.
Both of the above were shaped the same with the plugs angled downward at their back sides.
All the later switches were similar to each other with a single plug pointing straight out from the back of the switch. Some of these have screws or wire/spring type retainers that aid in their disassembly and a few have crimped sides and a couple just can't be opened without breaking them.

You could replace the resistance with a correct value for 12 volt and the lamps you are using.

Don't forget that the non-Bendix type switches have a built in circuit breaker which is probably rated for the 24 volt load. Again if the lamps you use with 12 volt create an annoyance trip issue then just bypass it and add a new properly rated circuit breaker in line with the wire # 15.

Bretto · Post by **Bretto** » Thu Mar 03, 2011 8:25 am

The one I have has the connector right out the back and the sides of the case are crimped.