Guys I have been having problems with air getting into my fuel lines and after much chasing have discovered that the front fuel tank is running out of fuel while the back is not transfering fuel to the front as it should. Well today the fuel gauge started going nuts. It moves constantly to the point of going in circles. First question is how can I tell which sending unit is bad, in the front or rear tank? Well considering the trouble I have run into getting the transfer pump to come on and off as it should I pretty much was thinking of trying to find a single sending unit that I could use in the front tank to tell fuel level. That way I know what is in the front tank which the truck will be running on, and then wire the rear transfer pump to a dash mounted toggle switch so that when fuel in the front tank got low I could just switch on the pump and transfer fuel from the back tank to the front. Has anyone tried this or forsee any problems with this type of set up. Thanks for any info you could give.

their should be a relay for the transfer pump on the frame rail near front tank.