Re: 12 volt conversion on 1940 110 coupe

Posted by HH56 On 2019/5/18 9:19:43

Correct and apologies. I forgot all about the electric wipers on the 110 and 120s and a resistor would be needed.

I also forgot another item. If the car has Overdrive that is a bigger issue. A resistor will not work properly on an OD because how much of a voltage drop a resistor provides depends on the size and amount of current flowing thru it. Overdrives require varying amounts of current depending on the state they are in and with a resistor depending on current flow, it would need to be sized for worst case -- around 20 amps max when the solenoid is pulling in. At low current need times there would be a real possibility of not enough voltage drop and burning out a relay or part of the solenoid. Unlike the R11 ODs, no 12v repro parts are available for R9s and those electrical parts are hard to come by and expensive.

If you do need something for an OD, there used to be an ebay seller providing a 12v to 6v 20 amp electronic converter for use with ODs. His listing has expired and I didn't find another so I have no idea if he still sells them. Electronic converters used with ODs must be rated for use with motors and coils which eliminates a lot of the lower current conversion items typically found on ebay for use with radios etc but you might check and see if you can find the OD unit.