Gas guage not working

[rgeddes]

I have a 91 Four Winns 18.5 with a 4.3 engine. Last fall, I noticed that the wood above the gas tank was soft. This winter, I removed the gas tank and replaced the wood and figerglass around the gas tank. Everything went well. I was able to improve the reinforcement in the gas tank area. I used 3/4" wood instead of 1/2" and added some additional support. I put everything back together and the boat works great. However, the gas guage will not longer work. When I connect the wires, the gauge goes to full. There are three wires: Green, Black, and Red(or Pink). Right now, I have the red and green wires connected to the sending unit and the black wires connected to a bolt on the sending unit for ground. The gauge reads Full. If I change the wires around, the gauge will read empty. I've tried every combination and get get the gauge to work. Is this a wiring issue or do you think the sending unit may have been damaged when I removed the gas tank? Any other thoughts would be appreciated.

 

[gm280]

Re: Gas guage not working

Did you actually check to see if the sender unit was stuck one way or the other? It could be that the actual swing arm or float is stuck in the high position and therefore it reads high. Then you reverse the connections and it read low and nothing in between. Just a suggestion. If the swing arm or float isn't stuck and moves freely then you may need a new sender assembly...

 

[Silvertip]

Re: Gas guage not working

The pink wire is the only wire that goes to the sender. The other end is connected to the "S" (sender) terminal on the gauge. The black and green wire connects to the flange of the sender and then jumpered to the negative terminal of the battery. What you may have done is turned the nut to much when you attached the pink wire. This twists the metal strap under the flange so it contacts the metal support for the float arm and the potentiometer thus grounding the pink wire which pegs the meter. Here is a picture of what may have happened.

#2 is the bottom of the stud you connect the pink wire to.
#1 Is the plastic insulator that isolates the stud from the metal mounting flange.
#3 Is the narrow metal strip that can twist and touch the metal frame #4 which shorts the sender terminal to ground.

 

[rgeddes]

Re: Gas guage not working

I can't see the picture?

 

[Silvertip]

Re: Gas guage not working

Do you see a link or just an empty box where the picture should be.

 

[Tyme2fish]

Re: Gas guage not working

Fuel gauge testing

 

[rgeddes]

Re: Gas guage not working

I can see the picture now. It was version of Internet Explorer.. Thanks.

 

[rgeddes]

Re: Gas guage not working

Is there a trick to get the gauge to work right. It works fine when full, but stops between half and 1/4 of tank when empty.