Dual Tanks ? 84 Silverado
 

greetings, I recently acquired an 84 Silverado long bed with the dual tanks, what are the capacities of these tanks?

The rocker switch to change from left to right tank makes a clicking sound from right to left but not the other way. The gauge also goes berserk on the right tank. I am not really sure if the switch is functioning properly. Is there a schematic available that shows me gas tanks, plumbing and switching ? Is this switch prone to problems ?


Thanks in advance for the help.:chevy:

Chris

Re: Dual Tanks ? 84 Silverado
 

Don't know about your electrical issue but they should be 20 gallon tanks. Short beds got 16 gallon and I think some long beds did too? If they're really long under the truck, with no space on either end, then they're 20 gallon.

Re: Dual Tanks ? 84 Silverado
 

LWB trucks can have either 16 or 20 gallon tanks. Mine has 16's sadly, and it is obvious when you look underneath that you have a good sized gap between the tank and rear wheel well.

Re: Dual Tanks ? 84 Silverado
 

I would check the ground on the right tank if the guage is only acting up for that one. Once you verify that you have a good ground, then inspect your switch.

The ground should go from the sending unit on top of the tank to the frame next to the tank.

Re: Dual Tanks ? 84 Silverado
 

im going to second Palpositys comments here hes on the money

Re: Dual Tanks ? 84 Silverado
 

Not sure about that clicking sound - my 83 dual tank makes a slight buzzing motor type sound when switched from left to right. Could you define what "going beserk" means, exactly? Does the other tank function properly? If so, then I would suspect the sending unit in the bad behaving tank. Are you actually able to suck gas out of both tanks and run the truck when you select left or right? If so, then the selector switch and valve under the cab are working. If you search here and elsewhere on the net you can get a lot of tips on diagnosing gas gauge problems.
If you need a selector switch - less than $20.
If you need a sending unit - $40-$160, depending on aftermarket (Spectra) or OEM (AC/Delco). Aftermarkets will cause the gas gauge needle to bounce when you drive the truck.

Re: Dual Tanks ? 84 Silverado
 

The "going beserk" (needle flipping from way past full back to empty) seems like behavior from a short or bad ground, I'll check that first this weekend.


The clicking or buzzing sound upon switching the tanks only happens in one direction, not both. I am not sure if it is actually switching because even though I have filled the right side tank,(been running on the left since I got the truck last week) I have not been in a position to chance running out of gas. I'll check the ground then then try to run on the right side. Thanks for the help.

Re: Dual Tanks ? 84 Silverado
 

Let us know how it works out for you. And welcome to the forum!

Re: Dual Tanks ? 84 Silverado
 

I have a simular electrical issue..
My speedo, gas gauge, and all the other little gauges do the same thing when i turn the driving lights on