Thundercraft gas gauge

[Cottagefiend]

Hello, I have a (new to me) 1989, 16 ft bowrider. The gas gauge does not move at all when I put gas into the inboard tank. Does anyone have some hints about where I might start to trace the source of the problem? Any help at all is welcome.
Thanks!

 

[Boatin Bob]

Re: Thundercraft gas gauge

There are some quick checks you can do. First of all using a meter check for power (12v) on the back of the gauge with the key turned on. The gauge should have at 3 connections, power, ground, sender (might have a 4th if it has a light)

If you have power then pull the sender wire off (usually pink), the gauge should be even below empty? Then using a short piece of wire jumper across from ground to the sender pin, this should make the gauge go up past full? (key needs to be turned on for these tests)

If that all works then it's either a bad sender wire or bad sender, now you move to the gas tank where the sender is should see at least 2 wires, the sender wire (could be pink) and a ground. Remove the sender wire and touch it to ground and see if the gauges moves past full as it did above. If it did then you've most likely got a bad sender in the tank, this is the most common problem but the other tests rule everything else out first.

 

[Cottagefiend]

Re: Thundercraft gas gauge

Many thanks Bob, this looks like a good strategy. If it stops raining long enough, I'll give it a shot this weekened.
I see you're on Simcoe, I vaguely remember a few summers of my mispent youth at a friends cottage in Keswick and some dances at Jackson's Point. However now I spend my weekends on a small lake a little S.E. of Bancroft.

BTW, I found this while searching the internet if it's of any use.
http://www.catalina27.org/images/teleflexMF.pdf

Thanks again.

 

[Boatin Bob]

Re: Thundercraft gas gauge

Yes...we live in Keswick (I've been here since 1969) but we boat out of Orillia since we use the boat like a cottage, that way it gets us away from the house for a while. Used to have a cottage up near Bancroft, little south on 69?, small lake called Gunter, actually my wife was born in Bancroft, they lived on Baptiste lake.

Good diagram, shows a bit of what I was trying to explain, hope it helps....good luck!

 

[mustang5x0]

Re: Thundercraft gas gauge

Hello i also am having a fuel sending unit problem but my temptation has three wires to it and no float so trying to find a proper replacment is darn near impossiable,Now i have my boat parked on baptist lake and after i did the research on the lake and living here for 15 years i decided this year i am leaving it close to home and get used to it before i put it in the big lakes ,maybe next year we'll see LOL if you want the site for the link to the lake and it's history it's BLA -Baptist -Lake-Assotiation. I might have spelt the last word wrong but i think u know what i mean LOL thanks and enjoy