6v to 12v conversion

[flatheadvff]

Hope this is a simple question. If I change over a 6v gas vehicle/tractor to 12volt and change the fuel gauge to a 12volt, will the original fuel sending unit still work?

 

[Fixingfarmer]

Usually that answer is yes.

Evergreen restorations that sells the John Deere gauges that fit well and work sells them as a set gauge and sender together knowing they work together.

 

[Mule Meat]

Think the Ohms of the sending unit needs to be compatible with the gauge for them to work together.

 

[DanielW]

Not an answer to your original question, but something to keep in mind whenever a 12V conversion is discussed: I'm assuming you're using a Delco (or knock off) 3-wire or 1-wire? If using a 1-wire this isn't a concern. But if using a 3-wire, one of the popular ways to wire the 1 & 2 (excitation & sensing) terminals is to use the ready-made connectors that are available for them. They're cheap, readily available (Amazon and other sites have them), they have the molded plug that captures both spade terminals, and (most importantly) have a diode wired in-line with the lead for the excitation line so you don't have to worry about wiring back through a resistor/light to avoid the concern of regenerating back to the coil and not killing the engine when you hit the kill switch.

But of the last few I've done, two of those pre-made connectors have the diode backwards. So you'll have the two problems of i) no excitation, and ii) it'll regenerate power back to the coil when you shut down, so the engine won't actually shut off when you hit the kill switch. And others on here have reported the same problem. Whenever you buy one these days, it seems to be a 50/50 shot whether the diode will be wired the correct way around. Easy enough to fix: Cut it out, solder it in the other way around, and put a new piece of heat-shrink over it. Just a little irksome that you can't count on the manufacturer to have got it right. If you use one and find that it's either not exciting/charging or else the engine stays running when you go to kill it, this is likely your problem.

 

[Welding man]

Hope this is a simple question. If I change over a 6v gas vehicle/tractor to 12volt and change the fuel gauge to a 12volt, will the original fuel sending unit still work?

I am restoring a 1949 Ford fire truck. All the gauges are electric on it. I converted it to 12Volt and electronic ignition. I bought a special voltage reducer that installs on the gauge cluster that reduces the voltage back to 6 volts and takes care of the positive to negative polarity change.

 

[Mark-Ia]

Usually that answer is yes.

Evergreen restorations that sells the John Deere gauges that fit well and work sells them as a set gauge and sender together knowing they work together.

Evergreen now sells gauges for all brands.

 

[m16ty]

It may or may not work, the new gauge has to be the same ohms as the sender.
You can buy 12v-6v converters cheap (usually $5 or so) to run small amp loads like a fuel gauge. What I’d do is buy one of these converters wired to the gauge and just keep the factory gauge.