the ivpr is new, sending unit replaced, dual switch?

[mojobean]

I had an issue with my fuel gauge. Ahhhh the fuel gauge. A few years ago it quit working. Replaced the ivpr. Still didn't work. Shortly after that all my gauges quit working. I looked at the rectifier on the ivpr, fooled with that and got the gauges working. Except the fuel gauge which always tops out at 1/4 tank, regardless of which tank the dual switch is reading. I hooked 2 D cell batteries to the fuel gauge and it pegged out full. That seems strange because 2 D cells are a total of 3 volts, so theoretically it should read half full. I ground out the sending unit (as suggested by the tech article) and nothing. At this point it would seem as if I have a break in the wire to the sending unit from the gauge cluster. The wire seems sound, is there anything else I'm missing? Would the dual tank gauge switch be so dirty to create enough resistance to thwart the reading. any ideas would be helpful, this is a three or four year thorn in my side.
Thanks

[FORDification]

If you ground the sending unit wire and get nothing at the gauge, then normally you'd suspect a broken wire between the tank and gauge...either that, or a faulty gauge. But since you say you hooked the gauge up to some batteries and it works, I'd do a quick continuity test of that sending unit wire...that's probably causing the problems.

However, I have heard others say they also got faulty readings from dirty contacts in the gauge switch. One member recently reported he was able to carefully open up the back just enough to get some electronics cleaner sprayed in there, and that everything worked great after that.

[mojobean]

I took the switch off, after checking the wire to the sending unit, and open the back plate. What a crazy switch! springs and ball bearings wow! Cleaned it, put dielectric grease on the inside components and did my best to put it back together. not much of a difference except now the auxiliary tank pegged out the gauge. I figured the switch was now grounding out in the auxillary side. I found a replacement at a junkyard along with a new gauge cluster. Put it in and fantastico everything works except my instrument dash lights. I had a question on the ipvr , the rectifier(the coil winding on the cardboard). What does that do?

[Thunderfoot]

Glad you got it working

I had a question on the ipvr , the rectifier(the coil winding on the cardboard). What does that do?

that is kind a like a variable resistor, it's how you can adjust the voltage that the gauges use. It will generate some heat...
Is that the answer you were after??

[fordman]

there is also a simmilar spring in the headlight switch. it dimms the dash lights with a turn of the knob. it can also be locked to one side to hold the dome light on.

[basketcase0302]

mojobean,

That's cool you got it going.
Did you try to adjust the IPVR?

http://www.fordification.com/fuel-sending-units.htm

Basketcase

[mojobean]

Not on the new ipvr, but on one of the two spares i did. I turned the back screw with a pair of needle nose and then opened it up to see if anything broke on the inside. Everything looked ok. How much do you turn it to get the full 5 volts.

[fordman]

very little at a time until it works properly.