Oil & Fuel TC33D fuel gauge

[gildebbiz]

Been having trouble with the fuel gauge on my tc33d. I thought the float in the tank was stuck but not the problem. The gauge always reads full, even when low on fuel. Fuses are all ok. Also checked the connections to the gauge. Maybe my gauge has gone bad, any ideas.

Thanks, gil

 

[jinman]

Does the gauge stay at full when you turn the key off? If so, it might be physically stuck in the full position. The next thing I would check is to disconnect the wire going to the float to see if the gage drops. Using a VOM, you should be able to read about 250 ohms at the tank side of the connector when the tank is empty and about 35 ohms when the tank is full. Therefore, removing the connector should indicate infinite resistance to the gage and the needle should pont to empty. Be sure you read the the tank side of the connector between pins A & B. That will tell you if your float is stuck. Remember, it should be low resistance when full and high resistance when empty.

 

[gildebbiz]

My gauge shows full when ignition is off. It does not look like it is stuck. Will take gauge out and check. About testing the wires, I'm not much of an electrician and doubt if I can find where they are. Will try though. Thanks alot.

 

[jinman]

If your gauge reads full when the key is off, then look no further. The problem is in the gauge. You might get the needle loosened up if it is only dirty. My gauge sticks at the lower end and a light rap on the face of the gauge makes it work everytime. Yours may not respond so easily.

 

[gildebbiz]

Just got done trying what you said. Put the meter on the wires going to the top of the tank and the meter went all the way over to "0". I also took off the dash panel and tried to get at the gas gauge. I moved the needle to see if it was stuck, it wasn't. Turned the key on and the needle moved alittle but didn't work when I turned the key off. Must be the gauge. Thanks again.

 

[Eagleview]

I'm not saying it is the case but some cars/tractors have the gauge reading while the key is on or off . If it this type , a pinched sender wire shorting to ground will have the needle go full scale .

 

[jinman]

Just got done trying what you said. Put the meter on the wires going to the top of the tank and the meter went all the way over to "0".

If you could drain the tank and then read a bit over 200 ohms, that would tell you that your tank float is working properly for sure. Analog (with a needle) ohmeters have to be zeroed to get an accurate reading, especially on the lower scales. You put the leads together and adjust the zero knob for exactly zero ohms. If you leave the meter on the 1000 ohms or greater scale and try to read low resistance, the needle often looks like it is pointing to zero. On a digital meter, you don't have to zero the scale, but you need to be in the 100 ohm range to get a good reading. If you have an expensive auto-ranging digital meter, then you don't have to worry about any of this.

One other thing to check with the ohmeter is whether you have a short to ground, but from what you said about the gage, I think that is where your problem is and not a ground short. I'll try to look up your part online and see if it is replaceable. I'll get back to you in a later post or edit this one.

EDIT: I checked Messicks.com and found that they have two of the TC33D temperature gages in stock. The part number is 86540853, and sells for $51.59 each. With shipping, that will probably make it over $60. It's too darn expensive, but it's a custom gage. You just have to grin and bear it.

Also, I want to give you a link to my post on where I replaced my temperature gage. The fuel gage mounts in the instrument panel the same way as my gage, so this post will be helpful in showing you how to get the gage out of the instrument panel. Once you have the instument panel out, look at the gage to make sure it is still stuck on full. If so, go ahead and pull it out of the instrument panel and replace it.

Gage removal

 

[gildebbiz]

Gentlemen, you have all given me many options. I will be busy for awhile trying to repair the gage. Jinman your photos were excellent on you temp. gage. I'm sure its the same for the fuel gage. Wish me luck.