6V to 12V Instrument Cluster

Has anyone here successfully operated a 6V cluster in a 12V electrical environment? I have a 1955 which had a special cluster which is the same as all others beneath the surface but has different facing so I can't just order up a 12V cluster. I have read two methods:
1. A voltage regulator on the power lead to the cluster which will power the 6V bulbs and gauges correctly.
2. Powering the cluster with 12V, changing the bulbs to 12V bulbs and putting a voltage reducer on each feed line for the temp and amp gauges.
Any advice or warnings?

P.S. does anyone have a detailed wiring diagram for the cluster

 

Is this what you are looking for?
http://www.speedwaymotors.com/xq/as....20/cont.1/intPgNo.2/redirect./qx/product.htm

 

I didn't know these were even available, not to mention reasonably priced. That should solve his problem..

 

I have a Runtz that I am going to install soon.

I am swapping all bulbs to 12 volts, so the only things to deal with are the gauges.

So, given the fact that all the 6 volt clusters had a regulator that controlled the gauges from the factory, I was planning on putting the Runtz on the regulator, not the gauges.

I have never quite understood why the gauges had to have a regulator in the first place; it appears it is 6 volts in --- 6 volts out. Perhaps it is some sort of current regulator so that the two gauges don't interact, or more likely, some sort of current limiting circuit so that a very small current flows through the gauge.

I do know that if the regulator is deleted the gauges burn out - or at least that was my experience many years ago on a 66 cj5

 

Cool, Let's hope I haven't fried my new gauges. In short: Power lead + RUNTZ + Existing Regulator = Gauges that work.

 

I had extremely bad luck with those. I had a 6V fuel gauge in my '55 (has an M38-A1 dash so it has a separate gauge) and got one of those for it. It worked for a week before it broke. Bought another one..Worked for 2 weeks, then broke. I just ended up buying a 12V gauge.

 

That is not encouraging. I received this reply from a guy who sells odd electrical items and a simpler solution on e-bay (autorewire.com) to resolve this issue:

"The best thing to do is to use the 12 to 6 volt diode that sells for $3.00 each and replace the 6 volt lamps with 12 volt units. The larger ceramic resistors will allow too much current to properly operate the gauges. The diodes regulate the voltage to 7 volts regardless of input voltage which is the better choice.

If you would like to purchase these they are $3.00 each and shipping and handling is $ 0.75 for the first one and $ 0.25 for each additional one. If you are in the great state of Caul-e-for-ea you will need to add $0.23 each for the Governator.

Thanks for the inquiry and let me know if you need anything else in the way of automotive electrical supplies for your project.

Al "

 

I'm not sure how connecting the Runtz to the factory gauge regulator will work. - it may not work, but I'm going to give it a shot.

I thought the Runtz looked to be light duty, and I got it from JC Whitney, so I have concerns about quality.

I've got one of the "willys" logo speedos that I am trying to adapt to 12 volts in a 3B.

Now, if I had a 12 volt battery with a 6 volt tap that would be perfect.

I just called the battery place and left them a message asking about the 6/12 volt battery.

Who knows? maybe they make such an animal!

kamel

 

I drew a blank on a 12 volt battery with a 6 volt tap. Apparently they used to make them, but they are not available in the general market today. I wonder if there might be a connection in Hemmings for something like this.

My battery guy suggested a separate small 6 volt battery to power only the gauges.

I don't think that is a very good idea.

So I went to the workbench and hooked up the Runtz on the regulator input, grounded everything properly, and then connected the fuel sender to the fuel gauge and temp gauge (separately).

Well, it seemed to work fine with the 12 volts input. Simulated full and it read full, simulated half tank and it read half tank, simulated empty and it read empty.

I'm convinced, so it gets installed for real later this week.

Now, if the Runtz hangs in there everything will be OK.

 

http://www.centechwire.com/catalog/accessories/zr2.shtml

Here's another option.

 

I spent some time at NAPA this afternoon and was happy to find a guy who didn't stare at me like I was insane. I learned that the 1.5 ohm ceramic voltage regulator seen above, available from several sources for $18 is readily had from NAPA for $5.40. Also that they stock the necessary 12 bulbs for .89/ea. I'm going with the diode type voltage reducers $3 from either AutoRewire or Centech (probably the same technology as the Runtz $18) as it sounds necessary to make the gauges work correctly.

 

Can you post the NAPA part number, in case the Runtz goes south?

thanks

kamel

 

The reason 12V Jeep systems have regulators on the fuel gauge is to drop the voltage down to a nominal 6 volts or so. This is to give the gauges a steady voltage so that they always read correctly regardless of where your actual 12 volt output is, which may go to 13 or more volts or drop below 12. No matter where the high side is, the gauges will be getting just the nominal 6 volts. On a 6V system I would suspect there was a similar setup, but I'm often full of it, too. This built-in regulator also supplies the lower voltage to run the points so they don't burn up as fast. That's where I am now; I need to redo the wiring to the coil and temp sending unit off this low voltage, as it was originally. Or so I recall.

 

Moved as this topic is not related to restoration.