[Flat Ernie]

Originally Posted by drolston

The horn is the trickiest. The horn relay must be changed, and that is not a big deal. But I have found no way to reduce voltage to the horn itself for which the horn still works. The horn actually works on +12 volts but sounds more intense. It might burn out if you laid on it too long.

You can, and probably should use the 6V horn relay. It doesn't care about polarity and the 6V units had heavier contacts. The horn will be much louder and 'angrier' (I like it that way), but short blasts are the order of the day. The 12V relays can and often do stick 'on' and you have to pull a wire off the horn or relay to get the horns to stop. Never had that problem with 6V relays.

Originally Posted by wga

From Ron Francis Wiring: VR1 is a clean easy setup for 12V to 6V conversion. No resistors to heat up. Connect to 12V, clean consistent 6V out the other end will take
care of all you gauges.
Next to what oil to use, the most discussed on this board. OP should take
some time and search for previous posts on 12V conversions.
https://www.ronfrancis.com/prodinfo.asp?number=VR-1 $60.00


https://www.napaonline.com/en/p/ECHIR1

$72.00 from NAPA

That's the same kind of unit that Ford used up into the '80s. It's a chopper unit. It basically turns the full 12V on and off over and over again so that the gauges think they're only getting 6V. Works pretty good, but there are better solutions...that are cheaper.

I'm a fan of the fully electronic L7806 CVR. These little gems cost less than $0.10 each and can take anything up to about 19V and always output exactly 6V.

Only a CVR (constant voltage regulator) will produce a constant output of 6V. The choppers and dropping resistors will output some lower amount around 6V based on whatever input voltage it gets. So if your chopper puts out 6V when only the battery is connected at 12V, but your alternator is putting out 14V, the chopper will now put out 7V (or thereabouts). The only gauge that this matters on is the gas gauge. Even the stock systems will show one reading when going down the road at speed, but when you stop and idle and the generator cuts out and voltage drops slightly, the gauge drops too. With a CVR, this is eliminated.

You can get them at any decent electronics store, order online, and even eBay sellers have them. 1 will run the three gauges most of our old cars have, but they're so cheap, I always run one for each gauge. Simple 3-wire hookup - 12V in, ground, 6V out.