[Oilyrascal]

Im guessing the fuel gauge as well, thanks again

[the okie]

go to the Ford Truck Enthusiasts Forums and do a search in1980-1986 Bullnose
trucks.There is a writeup on the regulator

[Big Cliff]

It will make a difference witch wire is on the positive see if one post has a plus or minis or one is gold and one silver or look at the bottom of the gauge way the needle will move the way the currant will flow to make the needle move,

[timothale]

I couldn't find my truck shop manual I had for my old and sold 86 truck. I read your questions and info on the ford truck enth. forums. My 2 cents worth, The 66 Mustang CVU has to be grounded, I don't know about the truck one. The power flow on a Mustang is a feed wire from the ACC terminal on the key switch to the 3 gauges, An ammeter or Battery voltage meter does not get that wire feed. And I don't have My old instruction manual From Factory Five for the Cobra Kit car using 80's mustang parts. One of the options was to use the stock Mustang gauges like you are doing in the Cobra instrument panel . and wire them instead of Buying the Smith Gauges (a few more dollors.) The FF cobra instructions also told how to use radio shack led's for panel lights. Years ago I used some Ford truck gages in my willys but was able to use the stock willys cluster and willys light sockets with 12 V bulbs.

[Oilyrascal]

Thanks, as you can see if you have been reading both forums there are different suggestions on how things were and how they should go. At this point I need to start playing around with the gauges, figure out how to read them with a meter and go from there.

[PatM]

I do think timothale has it right. All the gauges rely on a sensor, except the ammeter/voltmeter. Establishing a constant, steady voltage for power makes sense here. What the ammeter/voltmeter does is REPORT the lack of stability.

PatM

[Oilyrascal]

Originally Posted by PatM

I do think timothale has it right. All the gauges rely on a sensor, except the ammeter/voltmeter. Establishing a constant, steady voltage for power makes sense here. What the ammeter/voltmeter does is REPORT the lack of stability.

PatM

111 Thank-you

[cobalt327]

Originally Posted by timothale

The 66 Mustang CVU has to be grounded...

I'm just not seeing that. Do you have a different wiring diagram than mine?

[timothale]

Back in the old days the elect tech-repairman did not use those parallel line diagrams in the factory . We had large blow ups of the ones on the Hammer website. there is a link for the wiki colbalt327 posted above. or google hammar mustang wiring diagrams. both the Hammer pictorial shows a black groung wire to the CVU and down the page, the schematic shows the CVU grounded. Those parallel line diagrams made it possible for the draftsman to get everything on one page, I reduced the labor required to build a wiring harness 30 % by building harness per the print , then laying out the harness so it looked like a tree on a tilted sheet of plywood, it made routing the various wires a lot faster and final installation of the harness was easier.

[cobalt327]

Originally Posted by timothale

Back in the old days the elect tech-repairman did not use those parallel line diagrams in the factory . We had large blow ups of the ones on the Hammer website. there is a link for the wiki colbalt327 posted above. or google hammar mustang wiring diagrams. both the Hammer pictorial shows a black groung wire to the CVU an down the page the schematic shows the CVU grounded.

http://hammar.dyndns.org/~djhamma/wiring/1965/1965g.jpg shows no ground, just wires in and out. I suppose it could be said to be grounded by the attachment bracket, but my point is it need not be grounded to lower the current from 12 vdc to 5 vdc. If it did, there would be the symbol for a ground.

[timothale]

I used the 66 diagram and it shows it grounded with a black wire. I remember we had some grounding problems and changed the engineering specs to an s 36 finish (gold colored ) for ground screws in various places. I had Mustang Elect systems for a while.

[cobalt327]

Found a schematic that shows the added on wire. Might be an RFI thing. It is not needed for the unit to function, though.

[timothale]

I never took one apart to see how it works. ..Just when we got all the bugs worked out they do a major design change , then have to start all over, Cougar Electrical systems were a nightmare, and the dealer repair-warranty costs were more than for a T bird.

[cobalt327]

When you did a running change to the plating, say, what was done w/the unmodified parts on hand?

[cobalt327]

Originally Posted by cobalt327

Found a schematic that shows the added on wire. Might be an RFI thing. It is not needed for the unit to function, though.

I should add that if it's made the way I think it is (cheapest method) it wouldn't need a ground. But adding a ground to the case (not either terminal) will not hurt anything.