Packard Forum Index » V-8 (1955-56)

How do you check ohms? Where do you place wires from gauge? Sorry dumb about this.

You will need to use a Multi-Meter that can measure ohms. Typically the multi-meter leads go inline (in series) with the circuit you are testing.

A google search should provide you information on how to use a multimeter.

If you don't already have a multimeter, getting one would be a good idea for lots of other things. Sometimes almost indispensable like when checking for shorts. Sears has decent ones at fairly low cost and even some at Harbor Freight or Radio Shack are tolerable. Digital is easier to read but some cheap ones still have a meter with a needle.

When you do get one, select ohms and place the two leads on the sender. One lead to the terminal, other to the case or mounting plate--doesn't matter which wire in this case. Move the float up to top and it should read around 10 and hanging down, around 80.

I would recommend using the meter because it is easier to check by yourself but you could do without by grounding the mount like it was installed on tank and connecting the gauge lead to the terminal bolt as normal. Move the float and the gauge should follow. Since the gauges are thermally operated, will have a bit of delay in response while the heater strip does it's thing.

Connect one wire to the fuel gauge wire. Ground the other to the body of the sender. It does not matter which goes where but if you want to be technical put the pos+ on the wire and ground the neg-. Anywhere on the round part will do. Now move the float slowly, the ohm meter reading should go up and down as you move the float up and down.

I tested the ohms and the meter was on 1 when I started the readings were 12.1 and 97.5. Will this gauge work in my 6 volt pos ground car?

Ohms are close enough. Important thing is the full end never gets close to 0 on this style gauge. Average is around 10 so 12 is OK. The empty end is a bit high. Won't hurt the gauges but not sure where the needle will start to register properly.

Since both ends are slightly higher than optimal numbers, you may notice just a slight shift in gauge reading from the original. With full tank, the gauge needle might indicate a bit less than it used to and with the high other end, the half tank will be reading less. Might take a tank or two for you to get a feel.

That gauge reading also depends on the float travel so one other thing to check is if the float length or travel is about the same so the full and empty points are similar between new and old.

As long as the sender is for the year Fords & Tbirds mentioned in several other threads in the last year or so, then the sender should work. Several have replaced their originals and those Fords units were a drop in.