second tank problems
 

i was on my cigarette brake at school and i was sitting in my truck when i got bored and decided to flip the switch to see how much gas i got in my second tank and it went WAY past full...now the problem is...there should be anything more then a gallon or too of gas in that tank so whats messed up on my truck

Re: second tank problems
 

Mine does the same thing all the time, just turn the key on and off and it should reset itself and give you a true reading.

Re: second tank problems
 

This may reset the gage unless the sender is bad or the switching valve didn't switch all the way. Switch it back and forth several times to see what happens. Ask yourself if this has happened before. Switching valves are problematic at best in our trucks. I switch mine when 1 tank is at about half or a few times a week to keep it operational. If you don't use it, you'll loose it. jim

Re: second tank problems
 

If you dont use the tank often, you may have sulfur build up on the fuel sender card. It will make it stick. If the truck will run off of that tank, put gas in the tank and add some chevron tecron fuel additive. It should clear up. Also like Jim said switch the tanks often to keep the valve working.

Re: second tank problems
 

I use both tanks all the time, and I put a brand new GM switching valve on it just 2 years ago, so it must have something to do with the sending unit, but I have had the problem with both tank to.

Re: second tank problems
 

The sender card can get sulfur build up on it causing it to have and open circuit. My old truck did it all the time.

Re: second tank problems
 

When mine went way past full, it was the switch. They used some kind of foam to seal the switch (on the dash) and it had broken down and gotten between the contacts, making a bad connection on most of the contacts. I just took it apart and cleaned it out and Now it works perfectly. Take your switch apart if it's old, it's easy and free. Next step would be all connections, most likely outside the cab. The connections right on the top of the tank stay extremely filthy, but are hard to get to. Also check every ground you can find. Good luck

Re: second tank problems
 

guess I was lucky enough to have all that stuff gutted by the PO, i just have a petcock click it to the passenger side, it's that tank, drivers side is that tank, straight back is off... guess it's kind of a dummy switch since it's almost hidden under the seat