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gauge repair?

hey guys been on a fix up interior kick

replaced my rust filled gas tank and got a new sender installed in it. so the fuel gauge kinda works again. the gauge will read 3/4 of a tank when its full and 3 needle widths below E when it has 4 gallons left. i cleaned the gauge ground and i have 12v at the sender. is the gauge bad? should i just drop the tank and "calibrate" the float on the sender?

also i kinda want to get the amp gauge working. i read the t/s steps in the manual. it says check the connections at the circuit breaker. but were is it?

last random question which isn't gauge related. will any older after market know style radio fit in the radio bracket. i really don't listen a lot of music while driving but every now and then its nice. and i kinda want to stop looking at a broken radio.
 

fatherdoug

Tonto Papadapolous
Fuel gauge - Did you also replace the float when you replaced the sender? In my case, a very small hole in the float caused the float to fill up enough to cause the gauge to only read 3/4 full, when the tank was actually full. The '78 Ford manual posted on the manuals subforum also lists some ohm guidelines for what the readings should be in the empty position vs full position. I don't remember what those readings are.

http://www.fordtruckfanatics.com/forum/showthread.php?t=31340 Check section 33-20.

Do you have 2 fuel tanks on the truck, and have the connectors been reversed?

I don't know about a breaker on the amp gauge. You probably know this, but even with a fully functional amp meter, there is very little movement of the gauge from charge to discharge. Turning on the lights with the engine off should show a slight movement to the left of the middle point of the gauge. Are other gauges not working or fluctuating up/down? Then it could be the IVR on the back of the instrument cluster, or a faulty voltage regulator from the alternator.

Radio - Any 73-79 knob style truck radio should fit if you have the original dash bracket. I seem to remember the car radios not fitting because the depth of the knobs were different on car vs truck.
 
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Thanks Doug. i totally missed the fuel level ohm section.
i have a single 19 gallon rear tank. i been suspecting its a wiring issue, sure hoping it isn't a float issue. I really don't want to pull that tank again.

all my other gauges work right but i had a spare IVR and a nicer looking fuel gauge so i swapped those in today. no change.

the amp meter gauge never moves off center. key on all loads on (wipers, headlights, fog light heater). i think i found the circuit breaker on the fender. it just never click in my mind until today when i started following wires. i have some more testing to do but it cold outside. i replaced the voltage reg with a solid state bwd one last year but that doesn't mean it good. truck charges fine, maybe a bit high at 14.7v but its not 15.5 or 16v.
 
hey guys been on a fix up interior kick

replaced my rust filled gas tank and got a new sender installed in it. so the fuel gauge kinda works again. the gauge will read 3/4 of a tank when its full and 3 needle widths below E when it has 4 gallons left. i cleaned the gauge ground and i have 12v at the sender. is the gauge bad? should i just drop the tank and "calibrate" the float on the sender?

also i kinda want to get the amp gauge working. i read the t/s steps in the manual. it says check the connections at the circuit breaker. but were is it?

last random question which isn't gauge related. will any older after market know style radio fit in the radio bracket. i really don't listen a lot of music while driving but every now and then its nice. and i kinda want to stop looking at a broken radio.

Perform all checks possible with the tank in place. If the problem does not resolve, remove the fuel from the tank. Check the float for correct buoyancy. When the tank is oriented normally the gauge should show near "E". Invert the tank and the gauge should show near "F". If it doesn't bend the float arm and retest.

The Ford ammeter is famous for being near useless. If you would like to get it converted to a voltmeter with a lot of needle movement, go to http://www.rccinnovations.com/index.php?show=menu-volt-all

I don't know the answer for the radio question.
 

Jasperrc

Texas Chapter member
I don't know if it helps or not but I had ground issues with my truck that caused all kinds of odd gauge behavior. The fuel gauge started reading right when I added ground straps between the frame and block and frame and body. Actually this solved several odd lighting issues as well.
 
missed this post. Russell, very good advice you have there. while not my problem (ran a test lead up to the battery before posting) grounds seem to often be over looked. i ran a bed, a cab and a engine ground made 4 gauge wire when i started this project a few years back. due to all kinda of electrical issues. very good advice.
 

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