[RodFather]

I think this is an electrical problem somewhere (unless the unit just doesn't work).
I have a VDO sending unit and it worked fine for about the 15 minutes I had it hooked up. I dropped my fuel tank, and pulled it at that point. Now that it is reinstalled (a week later) I can't get it to read properly. the needle goes way past Full and stays there.
I pulled the unit out thinking I had a bad ground or connection. Both were showing good. I held the unit in my hand plugged and unplugged it several times and jiggled the float arm it went to Empty a couple of times, but would not stabilize at any location (full,half,empty).
I am 100% getting a good ground. The other wire is showing 6 volts. I am using a fabulous It's-a-Snap harness, and I feel like I'm trying to tune in a TV with rabbit ears. Everything is hooked up on the gauge as it was a week ago.
Any thoughts?

[docvette]

Doc here,

Sounds like the rheostat in the Sender is Shot, (intermittent or mechanically broken) You just might want to replace it.

The Gauge on most units will drive to full when ground is lost or intermittent, Are you Absolutely Sure the TANK is grounded? That should have a black wire that runs From the Tank to the frame..other than that, the only ground it sees is the fuel lines..as the tank sits on rubber straps..

So If the tank is grounded, and the wire to the gauge is good..I'd go with a new sender..As you said it was intermittent holding it in your hand..good clue the rheostat is toast...


Doc

[RodFather]

I'm using a tank's fuel tank (it's poly). The VDO sender has a ground strap on it and the sending wire. I think it's a gonner as well. Maybe VDO will replace it since it's new, but I won it a year ago (no receipt).

[docvette]

Doc here,

To test the rest of the system, go to radio shack and get the following value 1/4 watt resistors,

30 ohms, 60 ohms, 90 ohms, 150 ohms, 200 ohms and 300 ohms (or as close to those values as you can find...)

Insert each on the sender line, if it's a 30 to 90 ohm gauge, 30..60 and 90 should give you empty, 1/2 and full readings (or about that)

If it's 90 to 290 the others will give you those readings..

If thats all good, it's the sender for sure..

Doc