Hi Guy's, I have a 78 F100 Cleveland 351 4x4.

I have read that a lot of people have problems with the original temperature and fuel level indicators on their trucks. Apparantly they were not so good when the trucks were new?

I have attached a description of the system.

My gauge was not so good. Now its gone worse.

I was thinlng about using the IVR7805 ( 5V regulator) that I already use in the truck. Only now using an electronic mA digital indication panel instead of the bimetalic gauge in the cluster.

Has anyone done something similar or is there a better way?

Thanks,

 

In general, as new, I believe the fuel level and temp gauges were quite functional and useful on these trucks. The ammeter (if equipped) was not very useful... it basically showed little or no movement as current flow varied.

The biggest problem with the fuel gauge now is on the tank end. Re-pop fuel level senders often do not have the same winding and resistance characteristics as the original.

For the temp gauge, variation in readings may aggravated by age/condition of the gauge itself and variations in replacement senders.

If you could program or map your digital fuel and temp gauge unit to actual characteristics of the senders you are using, I believe you could get accurate readings.

 

The fuel sending unit float is made from two pieces of brass soldered together. Solder breaks down, gas seeps in, float settles to the bottom of the tank.

C0AZ-9202-B (replaced B7A-9202-A) .. Float is available from Ford and fits ALL 1957/79 FoMoCo vehicles.

 

Hi, does any body know what the resistance is when the level is
1. low and when it is
2. high?

This will give me an indication of what the current is at theses two levels will be. Thanks,

 

Dent gauges are (roughly) 10 ohms full and 70 ohms empty.

 

Hi,
thanks Blue dn White for the resistive values.

Does any body know if the 5V fuel level system was from legacy or required for safety?

Thanks,

 

It needs to be regulated to some value so readings do not vary as the vehicle electrical system voltage fluctuates. I guess 5 v is safer than 12 volts. Is it a requirement? IDK. Aftermarket gauges are powered by 12 volts... though they may have a regulator or other current limiting device built into the gauge itself.