A solution to those of us with a mustang gas tank and stock gauges! Fuel Gauge Change

[Maximus]

I know not everyone reads my build thread so I thoguht I would also make this post its own thread for the chance that it may help anyone...

I didn't get but maybe 2 hours to work on the truck today, but I did get a major breakthrough.
To all of us using a Mustang fuel tank, we obviously can't use the original chevy fuel gauge, as chevy uses a 0-90 Ohm gauge and Ford used a 75-10 (backwards!) Ohm gauge until apparently 1986...
I was originally going to adapt the original fuel sending unit from my truck in the mustang tank, and bend the float to match that of the mustang unit. This would probably work just fine, but I have like 6 gallons of fuel in the tank, so pulling the sending unit isn't an option at this time... there creates option B...

I went to the local pick-n-pull junkyard in search of a fuel gauge, and came up with two. The first was about a 1964 ford f100. Looked good, but I wanted another choice so I kept looking. Then I came up with what I think was a 1974 Ford pickup. Brought both gauges home and started working. Because the later gauge looked to be in a little newer shape (obviously) I decided to work with it. Now I am sure some of you want a more stock looking end result, and if I simply order the decal kit for the 55-59 gauges I could put the sticker on the gauge to make it look more stock, and also change the needle if I wanted... but I simply dont care. I left the original ford needle and print because I know it will be most accurate to the gauge. I may paint the tops of the E and F later, but again, for now I just want a gauge that works! and I am thrilled with the outcome.

I drilled out new holes for the new gauge and used tin snips to cut excess gauge background, test fit it and found that I needed to space it up so I used a couple nuts to space it up.
After I was happy with the fit i cut some cardboard off of a piece of packaging do prevent the gauge from grounding out on the cluster.

Again, my crude methods may not be original or clean enough for some, but you all are welcome to take from my experiences what you wish! I will wire it into the dash tomorrow and see if everything works!!!!!

Now for the pics...

This is a photo of what the gauge cluster I tore apart for the gauge I used. This photo is an ebay auction item and it says 1973-79 Ford truck gauges... all I know is the truck was from the '70's


The other MAJOR breakthrough was finding the ONLY 1960's chevy truck (it was a dual headlight stepside but I was more focused on the harnesses of every truck then the years...) it had the EXACT harness setup I needed for my dash lights, turn signals and gauge power setup. It has an extra bulb socket that i will just tape off and leave on there...


Here are the gauges I bought. The one i used was the 70's gauge on the right.


holes drilled, i eventually hogged them out a little larger for adjustment in the opening


Gauge in place for test fit

[Maximus]

Here is one more photo of the fuel gauge a little further away

[Lextech]

I am not doing such a project----But, That looks great. I think I would have to buy the gas gauge sticker for it. Excellent write up.

Jeff

[Daze57]

good lookin - informative write-up

[_Ogre]

maximus, now that's using the old noggin. 2 thumbs up for that
i'm thinking a little black sharpie over the text might hide it...

[Maximus]

thanks guys! I hope someone else can benefit from my work so that I can give back to all that have given me ideas through my project.

I may buy the stock gauge replacement sticker background but for now, as i mentioned, I am just happy the gauge works and I didn't have to spend all but $8

I wired the sending unit wire to the fuel tank and installed the dash. After I wired everything up I was excited to see both the turn signal lights and fuel gauge work!!!
Sorry the pic is so light, the California sun is bright today...

[fabguy]

Y not get the correct resistive sending unit? They sell them pretty cheap, aftermarket. You can get a 0-90 ohm or a 90-0 ohm
Posted via Mobile Device

[Maximus]

Originally Posted by fabguy

Y not get the correct resistive sending unit? They sell them pretty cheap, aftermarket. You can get a 0-90 ohm or a 90-0 ohm
Posted via Mobile Device

because it was more convenient to drill into the gauge on my spare instrument cluster, and as mentioned, I have alot of fuel in the tank and don't want to bother with draining it. Also my mustang tank came with a brand new sending unit, one which I knew would work as it is in the intended tank.

Draining the tank, finding a sending unit that would fit the hole, bending and twisting the float rod so that it would read as the normal mustang tank did, and put it all back together, and refill the tank with fuel...

the gauge mod took all of 20 minutes (with the gauges already out)

I'm not worried about the originality of my truck so it was the cheaper/quicker fix for me. Thanks for inquiring though.

and because I am obsessed that the dash wiring is all working as it should, here is a photo of the cluster with the backlights on.

[apache200]

Cool mod!! simple fix to that problem.

[Maximus]

hold the phone!
My darn fuel gauge only read half full when the tank is full... more troubleshooting needed. Ill post how I solve the issue if/when I do. First thing i need to do is run the other ford gauge i have strait to the tank and see if it reads properly, I may have just tweaked my sending unit...

[vintageozarks]

Great post & alot of good info. I enjoy doing that kind of fab work & there are definitely No books on it

[55dude]

Great idea!Do you have the voltage reducer for the gauge? Ford used 6 volts well into the 80's for the gauges. We used to rob the voltage reducers when we did a 12v conversion on the AD trucks.

[noisey]

What he said. IPVR is what they are called. I hooked one up on mine, there would have been one on the back of the ford instrument panel that the gauge came from. My gauge works fine on my '58. With the mustang gas tank and an early '70's F100 fuel gauge. I mounted my gauge the same way as yours. I painted the face black and put the white dots on it with a toothpick and some paint.