Gas Guage on Starcraft Starfish Pontoon

Hi Fellow Tooners. I have a late 1970'ish 20' Starcraft pontoon boat. Yesterday the gas guage stopped working, the needle dropped to below empty. I had just filled the tank the night before. I checked the things I could think of, fuses, wires to the guage etc, and took the float apparatus out of the gas tank, all seems to be working, but still no gas gauge. This morning I noticed that my fish finder is not working anymore either, I don't know if it is related to the gas guage problem or not. Any suggestions you might have would be appreciated.
Thank you
Robert

Re: Gas Guage on Starcraft Starfish Pontoon

Sounds like a bad ground.

Re: Gas Guage on Starcraft Starfish Pontoon

First check for voltage on both terminals of the fuel guage. If there is no voltage, then look for a bad fuse or connection feeding the guage. If you have 12V on both sides of the guage, you likely have a sender problem. If you have voltage on both sides of the guage, an easy test is to short the terminals of the sender unit. If the guage goes to full, the sender unit is bad. If not, the guage or connections to the sender wires are bad. If you have the sender unit out, you can also check it with an ohmmeter. The resistance should be from near zero ohms when full to about 100 ohms (It has been a long time since I tested a fuel sender unit so I emphasize the word about). It should never show a high resistance at any position.

Check for voltage on the red wire of the fishfinder. No voltage = fuse or connection to the FF. If there is voltage there, then make sure the FF has a good ground. Voltage + good ground = bad FF.

In case you have never used a voltmeter, the black wire should be on a known good ground such as the negative terminal of the battery.

Re: Gas Guage on Starcraft Starfish Pontoon

Thank you, I will give your suggestions a try, that is very helpful.

Re: Gas Guage on Starcraft Starfish Pontoon

Silver Eagle said:

Sounds like a bad ground.

Click to expand...

That's what my problem ended up being.

I got plenty of good info in my thread http://forums.iboats.com/showthread.php?t=312251

Good luck

Re: Gas Guage on Starcraft Starfish Pontoon

The ground on a gas guage circuit is on the sender unit. It is normally a black wire.

Re: Gas Guage on Starcraft Starfish Pontoon

Hello Guys. I wanted to come back and say thank you once again for the information you provided. We found the problem with the gas gauge today, and, like so many problems the solution was easy and right before our eyes. The wire connections on the back of the gauge itself had come loose, although on first inspection they looked ok. We tighttened them up today and the gas gauge worked !! At the same time I had a look at the fuse panel and discovered what appears to be a bad connection on the panel where the fish finder was connected. I installed a new fuse in a spare spot on the panel, hooked up the connection and the fish finder now works. I intented to go over every connection now, clean them up and apply some electronic grease. It is wonderful to have a resource like the one here at iboats to find help. Thanks again

Re: Gas Guage on Starcraft Starfish Pontoon

Thanks for reporting back. So many people jump in here with a problem but never let us know the final solution so we can all learn a little more about these beasts we call pontoon boats.