Build Your Own Gauge CVR

[55 Fargo]

Came across this on Allpar website. This detailed instruction shows how to build a very simple, effective low-cost Voltage reducer for gas and temp gauges.

Here is the Link. http://www.allpar.com/history/mopar/electrical2.html

[JohnS48plm]

Thanks for the link, it's just what I need to make for my 1965 Barracuda dash gauges. JohnS

[fstfish66]

wonder if it would work for a  6 volt  wiper motor in a converted 12 volt car,,,,  65 baracuda,,one of my favorite cars of all time,,,any pics?

[Plymouthy Adams]

considering the amp draw of the wiper...look for a smoked device...

[DCurrent]

according to what I have read here on this site for the last few months, the gas gauge will work on 12 or 6v. I have not confirmed this yet with my own gauge, but I plan to do so (use the original gauge and change it to 12v) in the hopefully near future. I have been using a remote 12v gauge that the car has installed under the ignition. I certainly hope it works.  

[55 Fargo]

Absolutely not, the current draw would fry this in an instant, it is rated at 1.5 amps, you would need at least 10-15 amp rated resistor for an electric wiper motor. I used a 50 watt large resistor for a 6 volt blower motor, running on 12 volts, and it even gets warm. Buy yourself a decent voltage reducer, and wire it inline and be done with it.

wonder if it would work for a  6 volt  wiper motor in a converted 12 volt car,,,,  65 baracuda,,one of my favorite cars of all time,,,any pics?

 

Yup, in no time flat, call that a New York second

considering the amp draw of the wiper...look for a smoked device...

 

the 2 wire gauges apparently drop the voltage with an internal resistor, the 1 wire type gauge can get heated up real quick with the higher current, and fry bimetallic strip...

according to what I have read here on this site for the last few months, the gas gauge will work on 12 or 6v. I have not confirmed this yet with my own gauge, but I plan to do so (use the original gauge and change it to 12v) in the hopefully near future. I have been using a remote 12v gauge that the car has installed under the ignition. I certainly hope it works.  

[Plymouthy Adams]

the two wire gauge has an internal voltage regulator that is very much the same thing that is used today in 12 volt application..is a heated bimetal regulator..

[DCurrent]

So a two wire fuel gauge will have two posts on the back of it?

[Plymouthy Adams]

three....1 power input..two lines to the sender units...each side of the gauge splits the 28 ohms proportionally. Usually marked 1 and 2

[55 Fargo]

the two wire gauge has an internal voltage regulator that is very much the same thing that is used today in 12 volt application..is a heated bimetal regulator..

Oh okay, thought it was unique to the 2 wire Mopar gauges.

I do know there are those who use 12 volts through the 2 wire  gauges, without ill effects. On the 1 wire later gauges using 12 volts would be a problem?

I have tested my 1 wire gauge on the truck with 12 volts, but obviously no sustained use to fry things. The gauge when close to empty would be in the area of 73-78 ohms resistance which would not allow for a high amount of current to the gauge, but when full with less resistance gauge might fry, is that correct assumption?

[Plymouthy Adams]

early two wire as approx. 28-32 ohms spilt to ground via the wiper..the internal regulator is why most can run on 12 volts...the gauge internal regulator opens and closes at a quicker pace and some may seen an erratic needle movement...the repair manual covers this very well...the gauges did not change with the swap to 12 volts,,,instead the external constant voltage regulator was the difference, the two wire thermal was gone by then..

[55 Fargo]

early two wire as approx. 28-32 ohms spilt to ground via the wiper..the internal regulator is why most can run on 12 volts...the gauge internal regulator opens and closes at a quicker pace and some may seen an erratic needle movement...the repair manual covers this very well...the gauges did not change with the swap to 12 volts,,,instead the external constant voltage regulator was the difference, the two wire thermal was gone by then..

Okay, for reliable use, will use CVR of some type to keep gas and water temp gauges in good form...........