Gauges incorrect...voltage limiter upgrade

[billytuffnuts]

72 Demon, stock standard dash...

The fuel gauge for my car works kind of erratically...more like the sending unit is not calibrated for the gauge. If I fill the car up, the gauge will move all the way to full like it should. Problem is it quickly move towards empty afterwards. Just driving around it seems like it'll eat up an 1/8 of a tank. And everytime I park the car and come back to it, the gauge will read slightly lower than when I left it. When it gets to empty, it'll only take ~7-9 gallons of gas in the stock 16 gal gas tank. I replaced the sending unit awhile ago as the other was shot since I bought the car, can't remember which brand though but its basically still new even though I put it in a year or two ago.

After reading some posts on here it seems one possible solution is to bend the float arm as some aftermarket units arent correct. Right now the sending unit reads about 55 ohms and reads slightly above empty. Using 73, 23, and 10 ohm resistors I was able to test the fuel gauge it self and it is functional. All straps, grounds are there.

I also noticed the temperature gauge never goes past the 2nd hash mark on the gauge, even when my aftermarket mechanical temp gauge will show the temperature fluctuating 15-20*...Tested the gauge/sending unit wire with the resistors like I did with the gauge and those worked fine.

I thought I remember seeing on here what the temp gauge is doing is a sign the instrument voltage limiter is going bad...could that also be causing the low readings on the fuel gauge too?

I saw a solid state voltage limiter upgrade on ebay:

http://cgi.ebay.com/ebaymotors/ws/e...viewitem=&_trkparms=clkid=4849522254126948657

It says voltage is adjustable on this unit. Default at 5.10 volts. If im not mistaken, aren't our gauges a 6 volt system? If I used this would I be better off setting it to 6 volts?

Sorry for the long winded post, but I figured there would be a lot of basic questions asked so I tossed in all the info...

 

[67Dart273]

I believe they work OK on 5V. SOMEWHERE, Moparts, Madd, etc, there was a "do it yourself" project to use an inexpensive regulator and build one.

Here's one:

http://1962to1965mopar.ornocar.org/ml-instrument-voltage-regulator64.html

http://www.mopar1.us/instrument.html

http://www.allpar.com/history/mopar/electrical2.html

the high end deal:

http://rt-eng.com/mediawiki/index.php/RTE_limiter

at least one thread on the subject

http://www.forabodiesonly.com/mopar/showthread.php?t=86097

Another one is called a Runtz, just Google it

 

[billytuffnuts]

thanks for the info. I found a lot of that searching through here but not all of it. I'll have to decide if I want to take the time to make my own or just use an off the shelf version.

Any idea on if the ivr that I have now may be causing some of my issues? No point in replacing it if theres nothing wrong with it right?

 

[billytuffnuts]

took the sending unit out and wired it up so I could sit in the drivers seat, manipulate the float arm. it reads half full will the float arm about 3/4 of the way up. Once I move it down to about 1/4 to it lowest point the gauge starts reading empty. No dead spots when I ohmed it out, maybe ill pull the cluster and see if I'm missing any grounds and replace the ivr...

 

[billytuffnuts]

bump...any opinions on what to set the voltage limiter at? leave it at 5.1volts?