Gas Gauge 69RR

[TOMRR]

I know my Dash Gauge is good but the tank has been out of the car for two years and the sending unit is about 4 years old and new tank. I put 15 gal. gas into tank and the gauge move just pass the E Mark. I check the ground and even ran a second ground wire. The power. Plug at the tank has Electric but it make my test light flash like a blinker. Any Ideas ???

Thanks Tom C.

 

[Grabinov911]

Set your meter to measure resistance (Ohms). Then check the resistance between the sender wire post and the body of the sender (with the sender out of the car). The resistance should change essentially evenly as the float moves up and down. The ground may be good but the variable resistor in the sender may be dirty. If so, use a scrub pad and clear the contacts.

 

[bigmanjbmopar]

Sending unit wire only has 5 volts DC on it from the instrument cluster voltage limiter. sounds like the ground isnt that good, where have you placed the ground on the unit to tank? is your new tank stainless steel? can you take some pics? also have you tested the sending unit out of the tank?

 

[eagleone1983]

As they said there are specific Ohm ratings for the sending unit. 73 ohms empty, 10 ohms full. If it doesn't fall in that range you'll need to adjust or clean the plunger until it does.

 

[Yatzee]

The blinking is from the constant voltage supply and indicates it is good. The heater in the unit takes the full 12 volts and causes a bi-metal to open and close a set of points within. The heater only lets 5 volts beyond itself as it consumes the voltage/amperage to heat up. If you have a new tank I would recommend installing a tubular sending unit that isn't affected by sloshing in the tank and way more accurate at the gauge than one with a float. You can use your existing unit for fuel pickup only and remove the arm and float. I had the exact same problem on a project I did and after using the tubular type swore I'd never go back. They come in various lenghts and ohmages to match original float style.
Like this:

http://www.tanksinc.com/index.cfm/p...t_id=346/category_id=167/mode=prod/prd346.htm