6v Fuel Sending unit + 12v gauge

Niclas · Post by **Niclas** » Tue Apr 18, 2006 8:30 am

Hi all

I have a 6v sending unit and a 12v gauge.
Both are new NOS (brand unknown) for CJ2/CJ3

Is it possible to get them to work.
the Jeep is a CJ3B -56 converted to 12v

/Niclas

Post by **wesk** » Tue Apr 18, 2006 10:13 am

With a lot of dangerous experimentation you could eventually get the gage and sender matched by adding a yet to be determined amount of resistance between the gage and sender. By dangerous I mean elctrically destroying either the gage or the sender. You first must know how the gage functions. Does it read full or empty with zero resistance between it and ground with 12 volts applied to it?

Much simpler to buy the correct 12 volt sender for the 3B. By the way, the CJ3A was out of production in 1952. Willys didn't offer a 12 volt option until 1957.

Niclas · Post by **Niclas** » Tue Apr 18, 2006 3:35 pm

thx for answer Wes.

Problem is I can’t get hold of a 12v here in Sweden

But I do have the original 6v gauge still.

Is there any physical difference between 6 & 12v sender unit?

The sender unit I got with Jeep will not fit on the MD Juan repro tank.

The ring with all the screw holes in is much bigger, and the new one fits perfect.

/N

Post by **Ryan_Miller** » Tue Apr 18, 2006 6:37 pm

Niclas,

could you make an adapter that would allow you to fit the other sending unit?

Post by **wesk** » Tue Apr 18, 2006 7:28 pm

Just use the 6 volt gage with the 6 volt sender and install a transistorized 5 to 6 volt regulator in the power feed to the gage. These are very cheap and easy to find.

Here's a good tech site:
http://www.willys.i8.com/gbc/gauge3.htm#conversion
Another:
http://www.geocities.com/vk3cz/gauge-repair.html

Here's a transistorized 6 volt voltage regulator installed:

Niclas · Post by **Niclas** » Wed Apr 19, 2006 1:47 am

@Ryan

Had that in mind to.

@Wek

will sure try that.

/N

Post by **Ryan_Miller** » Wed Apr 19, 2006 6:43 pm

Niclas,

Be sure to let us know how things turn out.

Niclas · Post by **Niclas** » Thu Apr 20, 2006 4:25 am

Will sure do

/N

Niclas · Post by **Niclas** » Tue Apr 25, 2006 1:47 pm

Hi

Now I have tested the 6v sending unit with the original gauge.

first I tested it with a 6v source and only problem I had was related to grounding, just to make sure they worked.

And then I made the volt regulator with help of Wes picture
and testing it by feed it with 12, 14 & ~20 volt output was a stable 6.03 volt.

After that I tested it with full setup

12v to regulator ---> Gauge ---> sending unit moved the "arm" to full half and empty tank and got right respons from gauge.

you can get the 7806 in 2 different version .5 amp and 1.5 amp max
I bought the 1.5 amp version

Spent about $12 on componets and aluminum casing and 30min of my time.

/N

Post by **wesk** » Tue Apr 25, 2006 7:05 pm

Niclas,
Great news. Glad all worked out for you. Isn't the internet and these message boards just the greatest thing on the planet?

easters17 · Post by **easters17** » Wed Apr 26, 2006 1:21 pm

wesk wrote:Niclas,
Great news. Glad all worked out for you. Isn't the internet and these message boards just the greatest thing on the planet?

They are good but jeeps are the greatest thing on this planet (just my opinion)

Niclas · Post by **Niclas** » Thu Apr 27, 2006 8:48 am

Yes have to agree with you Wes

The Yahoo group and this forum is a great source for help and info.

Im almost (or maybe im) alone in Sweden with my M606
I know there is an M606A1/2 here to.

Most of the willys here are GPW/MB orginal or modified.

/Niclas