Bad tank selector switch, now won't start - The 1947 - Present Chevrolet & GMC Truck Message Board Network

81silverado · 05-15-2005, 12:58 AM

I recently tried to replace a bad tank selector switch (which failed...resulting in the switch not changing tanks and the fuel level needle going past, and staying past, FULL), now my truck acts like it isn't getting fuel to it and won't start unless I put some carburetor cleaner in the carburetor.....then only stays running for a few seconds. Any suggestions?

Russell · 05-15-2005, 01:39 AM

Bypass the valve until you can get a new valve :P

My truck did that to me, cept I was in the middle of nowhere with no tools less a pair of pliers to fix it. I was able to re-plumb it real easy, but yeah, I ran my battery dead trying to start it before I figured out what went wrong, lol I wound up waiting a few hours till a guy came and gave me a boost, it fired right up on like the second crank, of course!

Only time the GMC ever left me on the side of the road!

79BIG10 · 05-15-2005, 04:59 AM

I don't have access to my regular computer so I can't post my usual trouble shooting of this problem. So here goes what I can think of off the top of my head

1. Check the wiring at your fuse box. You should see a pink w/black stripe wire plugged in. If it is check the fuse for it. This is the power wire for the switch itself. This was the root of all my problems. If you have power to this then off to the next part.
2. The next place to look is the actual valve itself. Under your passenger side behind the cab inside the frame rail you should see the fuel valve. It should have either 3 or 6 ports on it. You will see a green wire leading to it. With the ignition key on and the switch to the left (driver) side tank take a test light to see if you are getting power. If you are not then you have a bad switch. If you are getting power then you have a bad valve.
3. If it's the switch itself (no power to valve) then you have to remove it. You have to access it from the ashtray hole. Unbolt the ashtray and set it aside. The cover for the switch is held in by two speed nuts. These are nuts that cut their own threads while turning on the plastic studs. Once the cover is off the switch will come out and simply unplugs.Take it to the dealer and and buy a new one with a cover and nuts. Reassembly is the reverse.
4. One more place to check is on the firewall for about 3 or 4 wires on a plug where the wires from the switch meets the inner firewall. The plug that meets the firewall on the engine side can get corroded. Look there but that usually doesn't come loose.

86swb · 05-15-2005, 08:10 AM

My right gas tank never worked since I bought the truck. Thanks, this information also helps me out also. Now I know what to look for to get mine up and running. Should I have the tank cleaned being that the tank has not been used for who knows how long?

81silverado · 05-15-2005, 11:18 AM

Thanks, guys!

81silverado · 05-15-2005, 01:42 PM

There isn't a fuse labeled for anything remotely connected with anything to do with the fuel pump, fuel switch....etc...fuel anything. I see the pink and black wire going in to the fuse box but it isn't connected to an actual fuse. Is the fuse associated with it, the closest fuse to where this pink/black wire connects? I replaced a fuse that looked bad and it fired up for about 15 seconds now won't start unless I put carburetor cleaner in the carb...then it will only stay running for a few seconds. I am getting power to the actual switch and power to the valve.

81silverado · 05-15-2005, 07:50 PM

Who would have thought. I decided to purchase a different tank selector switch and now my truck will start. The fuel gauge still reads WAY OVER FULL and I'm not quite sure which tank I'm operating on.

79BIG10 · 05-18-2005, 04:44 AM

If it's way over full then it sounds like you have a bad ground.

86 GMG · 05-18-2005, 07:31 PM

The Over Full Might Also Mean The Sending Unit Is Bad ???? When My Truck Did This I Replaced The Fuel Pump Droped Both Tanks To Check For Clogs The Hole Damn Nine Yards And Then Droped An Extra Piece Of Hose From Fuel Pump Truck Ran , Moved Back To Next Connection It Ran And Finally Discovered The Valve On Frame Died 55.00 ? I Think At Chevy Dealer Three Weeks Later I Was Driving Again It Really Mad Me Mad Just About Torched The Sob. Lol!!!!!

05-15-2005, 12:58 AM	#1
81silverado Registered User Join Date: May 2005 Posts: 12	Bad tank selector switch, now won't start I recently tried to replace a bad tank selector switch (which failed...resulting in the switch not changing tanks and the fuel level needle going past, and staying past, FULL), now my truck acts like it isn't getting fuel to it and won't start unless I put some carburetor cleaner in the carburetor.....then only stays running for a few seconds. Any suggestions?

05-15-2005, 01:39 AM	#2
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Bypass the valve until you can get a new valve :P My truck did that to me, cept I was in the middle of nowhere with no tools less a pair of pliers to fix it. I was able to re-plumb it real easy, but yeah, I ran my battery dead trying to start it before I figured out what went wrong, lol I wound up waiting a few hours till a guy came and gave me a boost, it fired right up on like the second crank, of course! Only time the GMC ever left me on the side of the road! __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

05-15-2005, 04:59 AM	#3
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,774	I don't have access to my regular computer so I can't post my usual trouble shooting of this problem. So here goes what I can think of off the top of my head 1. Check the wiring at your fuse box. You should see a pink w/black stripe wire plugged in. If it is check the fuse for it. This is the power wire for the switch itself. This was the root of all my problems. If you have power to this then off to the next part. 2. The next place to look is the actual valve itself. Under your passenger side behind the cab inside the frame rail you should see the fuel valve. It should have either 3 or 6 ports on it. You will see a green wire leading to it. With the ignition key on and the switch to the left (driver) side tank take a test light to see if you are getting power. If you are not then you have a bad switch. If you are getting power then you have a bad valve. 3. If it's the switch itself (no power to valve) then you have to remove it. You have to access it from the ashtray hole. Unbolt the ashtray and set it aside. The cover for the switch is held in by two speed nuts. These are nuts that cut their own threads while turning on the plastic studs. Once the cover is off the switch will come out and simply unplugs.Take it to the dealer and and buy a new one with a cover and nuts. Reassembly is the reverse. 4. One more place to check is on the firewall for about 3 or 4 wires on a plug where the wires from the switch meets the inner firewall. The plug that meets the firewall on the engine side can get corroded. Look there but that usually doesn't come loose. __________________ 1979 Chevrolet Bonanza Big10 "Tootsie Roll" 1985 Chevrolet Silverado (wife's) Member of the Southern Bowties Club "Don't underestimate how sexy a fat man who drinks to excess can be." Homer Simpson

05-15-2005, 08:10 AM	#4
86swb Born a Chevy Man Join Date: Apr 2005 Location: Navarre, Florida Posts: 10,221	My right gas tank never worked since I bought the truck. Thanks, this information also helps me out also. Now I know what to look for to get mine up and running. Should I have the tank cleaned being that the tank has not been used for who knows how long? __________________ John or 86 (Viet Nam combat Vet-BIG RED ONE) '65-'66 1986 Chevy SWB Silverado 1984 Chevy Longbed Silverado New Kia Sportage (Wife's car and she loves it) CHEVY, American made w/pride! If you can read this, YOU NEED TO THANK A TEACHER! If you can read this in ENGLISH, PLEASE THANK A SOLDIER! GOD BLESS AMERICA AND BLESS OUR FIGHTING TROOPS

05-18-2005, 04:44 AM	#8
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,774	If it's way over full then it sounds like you have a bad ground. __________________ 1979 Chevrolet Bonanza Big10 "Tootsie Roll" 1985 Chevrolet Silverado (wife's) Member of the Southern Bowties Club "Don't underestimate how sexy a fat man who drinks to excess can be." Homer Simpson

05-15-2005, 11:18 AM	#5
81silverado Registered User Join Date: May 2005 Posts: 12	Thanks, guys!

05-15-2005, 01:42 PM	#6
81silverado Registered User Join Date: May 2005 Posts: 12	There isn't a fuse labeled for anything remotely connected with anything to do with the fuel pump, fuel switch....etc...fuel anything. I see the pink and black wire going in to the fuse box but it isn't connected to an actual fuse. Is the fuse associated with it, the closest fuse to where this pink/black wire connects? I replaced a fuse that looked bad and it fired up for about 15 seconds now won't start unless I put carburetor cleaner in the carb...then it will only stay running for a few seconds. I am getting power to the actual switch and power to the valve.

05-15-2005, 07:50 PM	#7
81silverado Registered User Join Date: May 2005 Posts: 12	Who would have thought. I decided to purchase a different tank selector switch and now my truck will start. The fuel gauge still reads WAY OVER FULL and I'm not quite sure which tank I'm operating on.

05-18-2005, 07:31 PM	#9
86 GMG Registered User Join Date: Apr 2005 Location: Tulsa Oklahoma Posts: 943	The Over Full Might Also Mean The Sending Unit Is Bad ???? When My Truck Did This I Replaced The Fuel Pump Droped Both Tanks To Check For Clogs The Hole Damn Nine Yards And Then Droped An Extra Piece Of Hose From Fuel Pump Truck Ran , Moved Back To Next Connection It Ran And Finally Discovered The Valve On Frame Died 55.00 ? I Think At Chevy Dealer Three Weeks Later I Was Driving Again It Really Mad Me Mad Just About Torched The Sob. Lol!!!!! __________________ square body trucks an addiction or an investment either way they consume all my extra time and money

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