Dennis Carpenter Voltage Reducer
 

I am looking in MAC's Catalog at a Dennis Carpenter Voltage Reducer-Reduces 12 volt to 6 volt-Dash Gauges for $35.00 (SKU 66-62256-1) The only problem I see and it may not be a problem, is that it shows three gauges: FUEL, OIL and TEMP. My third gauge is a volt meter gauge for the battery. The TEMP Gauge is a mercury thermometer gauge on my 1939 Ford Deluxe Convertible. Will this device still work and what will my Batt gauge which is the third gauge in my cluster show? Thanks for y'alls help.

Re: Dennis Carpenter Voltage Reducer
 

You should be fine. If you didn't wire the batt gauge it would be pegged from the 12 volts. If I remember right there is one wire on ignition switch marked gauges and this is the feed for the three.

Re: Dennis Carpenter Voltage Reducer
 

When I converted my 40 to 12v I used a CVR (Constant Voltage Reducer from Ron Francis) to reduce the voltage to 6 V for the FUEL, TEMP, Oil gauges. In order to get the BAT. guage (which is really a volt gauge) to read accurately I isolated it from the other 3 gauges and used a 60 ohm reducer to reduce the incoming 12V to the BAT gauge to 6V. Read post #6 here.
https://www.fordbarn.com/forum/showt...olt+conversion

Re: Dennis Carpenter Voltage Reducer
 

Re: Dennis Carpenter Voltage Reducer
 

The reducer should put out a constant 6 volts. This is fine for gauges that need 6 volt power (not the sense line for say fuel). Hooking a 6 volts input to your voltmeter should show a constant 6 volts.

Re: Dennis Carpenter Voltage Reducer
 

The solid state CVRs will keep the reduced voltage constant and at steady state but the old units work in the same way that the old King Seeley gauges so the only thing constant about them is then the open and close the circuit at a high enough speed to fake the system into recognizing it as a constant. They were used on King Seeley Gauges but I don't know if King Seeley recommended this set up or not. Ford certainly used them well up into the 60s and maybe later in some cases but I always noticed un-explainable variations in indicator readings on an old 64 T-bird I once owned.

The unit mentioned may be a solid state unit but it's hard to tell with the way it is potted.