Quote:

not quite right.
The dash is grounded by the frame not a "ground" lead.
For the battery test, I would run the leads to the back of each gauge not to the circuit board.

That would run it through the regulator, but you stil would not be grounded. so it would not work.

To get power to the whole dash, I would run a ground to the frame of the cluster, then figure out which is the 12 volt pin to the dash and run the postive of the car battery there.

Then take the multi meter to the back of the gauges and see what it reads.



Right. You need to attach one wire from each end of your two battery thingy to the prongs on the gauge itself. For example - take 2 C cells (or AA or whatever) and tape them together as a long cylinder with the + on one battery connecting to the - on the other. Then tape a wire from the top at +, and tape another wire at the bottom on "-". Then touch the wires to the two prongs on the gauge. It'll take a second or two, and then the gauge will start to rise.

I don't recall whether it matters which wire (+ or -) goes to which prong. Worst case, just look at the circuit board and see which prong is getting power from the regulator, and use that for +.

To answer you direct question - the gauge does not need the sending unit to tell it what to to. The sending unit and the voltage regulator are varying the voltage to the gauge between 0 and 5 volts. By doing the battery thing you are applying 3 volts, so the gauge should go up about half-way.

While you have it out, use your ohm-meter to check all the circuit board connections. i.e. - touch one lead to where the regulator would plug in, and then touch the other end to each spot one of the gauge prongs would go on the circuit board. You can see the path of the circuit by just following the big green stripes on the board. Do this also for the other side of the gauge prong connection, and follow it across the board to make sure you get a good reading all the way around.

Last edited by Gusteve; 08/07/09 06:12 PM.