tank switches - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Lil Greg · 03-05-2003, 02:13 PM

Anyone have a diagram to wire up the duel tank switch on an 87???????? Its a non efi truck if that matters should i use an 87 switch or an earlier one?

PHOENIX · 03-05-2003, 03:42 PM

I dont know if the switches are different or not. Check out your LMC catalog for that answer. Brandon (79BIG10) has some expierence with problems on his system. He may be a huge help to you. I personally have not done anyhing with my dual tank setup, except replaced the dash switch (bought from LMC, quality is OK on this product, good for the price, very small pits in the surface of the plastic, you can only see them when you look close).

79BIG10 · 03-05-2003, 05:19 PM

I don't have a wiring diagram but I can help you out if you can tell me the problem. I've redone mine totally on the 79 when it went out.

87 STEPPER · 03-05-2003, 06:55 PM

Are you shure it's an '87? All 87's were EFI unless you or someone else removed the TBI sys.

But the switch's are differant i don't know what years it changed but i do know there not the same cuz iv'e got some out of the jy and they were form older trucks and they wouldn't fit my connector cuz one terminal has a key way on it so you can't intermix the two switche's.

Lil Greg · 03-05-2003, 07:52 PM

I just need to know how to wire it up from scratch the 87 frame im using has the 87 selector valve still on it and the 75 cab didnt come with duel tanks so ive got to wire it all up from the dash to the valve to the tanks.

gmcbob · 03-05-2003, 10:04 PM

I've got a wiring diagram from my '89 1-ton crew cab. It's probably the same (because it's the crew cab & still the 81-87 gm body style). I'll see if I can dig it up, but I don't have any way to scan it though.

Does you selector valve have the plug-in terminal that has five (maybe six ?) wire connections?

Lil Greg · 03-05-2003, 11:47 PM

Its got the weather pak connector but id have to run to the shop in the morning to count 'em

79BIG10 · 03-06-2003, 03:14 AM

The valve has either a 1 wire (green) wire or a bundle wires like mentioned. The 6 wire I think is for the 87 that had the fuel pumps in the tank. If you want to start from scratch with a different valve I have a schematic of the fuel line from a older truck like mine. Let me know and I'll email it to you.

gmcbob · 03-06-2003, 09:28 PM

Here you go - look over this. Hope it Helps!, let me know.

http://hometown.aol.com/gmcbobber/page1.html

79BIG10 · 03-06-2003, 09:53 PM

Here's a sized down size that I got from Mike Reeh awhile back. If you need a full size email me and I'll send it to you.

Lil Greg · 03-09-2003, 12:02 AM

Ok everyone im going to try to dig into this mess monday and ill use the diagrams yall gave me hopfully ill get it done i just couldn't bring myself to work on it friday i was so nice i headed to the lake, well thanks for your help everyone.

03-05-2003, 02:13 PM	#1
Lil Greg Registered User Join Date: Feb 2003 Location: Mansfield,Tx Posts: 54	tank switches Anyone have a diagram to wire up the duel tank switch on an 87???????? Its a non efi truck if that matters should i use an 87 switch or an earlier one?

03-05-2003, 03:42 PM	#2
PHOENIX Registered User Join Date: Oct 2002 Location: Phoenix, Arizona Posts: 4,703	I dont know if the switches are different or not. Check out your LMC catalog for that answer. Brandon (79BIG10) has some expierence with problems on his system. He may be a huge help to you. I personally have not done anyhing with my dual tank setup, except replaced the dash switch (bought from LMC, quality is OK on this product, good for the price, very small pits in the surface of the plastic, you can only see them when you look close). __________________ * AVOID: LOPER'S PERMORANCE / LOPERSPEED.COM OF PHOENIX, AZ & COTTMAN TRANSMISSION *

03-05-2003, 05:19 PM	#3
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,775	I don't have a wiring diagram but I can help you out if you can tell me the problem. I've redone mine totally on the 79 when it went out. __________________ 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

03-05-2003, 06:55 PM	#4
87 STEPPER STILL PLAYS WITH TRUX Join Date: Nov 2002 Location: Melbourne, Fla. Posts: 2,764	Are you shure it's an '87? All 87's were EFI unless you or someone else removed the TBI sys. But the switch's are differant i don't know what years it changed but i do know there not the same cuz iv'e got some out of the jy and they were form older trucks and they wouldn't fit my connector cuz one terminal has a key way on it so you can't intermix the two switche's. __________________ ~~Bruce~~ MY 87 STEPPER MY 99 2D/WD TAHOE

03-05-2003, 10:04 PM	#6
gmcbob Registered User Join Date: Mar 2000 Location: Phoenix, Arizona Posts: 57	I've got a wiring diagram from my '89 1-ton crew cab. It's probably the same (because it's the crew cab & still the 81-87 gm body style). I'll see if I can dig it up, but I don't have any way to scan it though. Does you selector valve have the plug-in terminal that has five (maybe six ?) wire connections? __________________ Bob 1978 GMC Sierra Classic K15 Shortbed, 350/350/NP203, 31's on Rally's, Restored to Stock Condition. Two-tone Russett Metallic / Buckskin. 1987 GMC Sierra Classic V1500, Longbed, 350 TBI, NP205, 33’s on Chrome Spoke with 4” Suspension Lift. Black. 2014 GMC 2500HD 4x4 Duramax Crewcab

03-05-2003, 07:52 PM	#5
Lil Greg Registered User Join Date: Feb 2003 Location: Mansfield,Tx Posts: 54	I just need to know how to wire it up from scratch the 87 frame im using has the 87 selector valve still on it and the 75 cab didnt come with duel tanks so ive got to wire it all up from the dash to the valve to the tanks.

03-05-2003, 11:47 PM	#7
Lil Greg Registered User Join Date: Feb 2003 Location: Mansfield,Tx Posts: 54	Its got the weather pak connector but id have to run to the shop in the morning to count 'em

03-06-2003, 03:14 AM	#8
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,775	The valve has either a 1 wire (green) wire or a bundle wires like mentioned. The 6 wire I think is for the 87 that had the fuel pumps in the tank. If you want to start from scratch with a different valve I have a schematic of the fuel line from a older truck like mine. Let me know and I'll email it to you. __________________ 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

03-06-2003, 09:28 PM	#9
gmcbob Registered User Join Date: Mar 2000 Location: Phoenix, Arizona Posts: 57	Here you go - look over this. Hope it Helps!, let me know. http://hometown.aol.com/gmcbobber/page1.html __________________ Bob 1978 GMC Sierra Classic K15 Shortbed, 350/350/NP203, 31's on Rally's, Restored to Stock Condition. Two-tone Russett Metallic / Buckskin. 1987 GMC Sierra Classic V1500, Longbed, 350 TBI, NP205, 33’s on Chrome Spoke with 4” Suspension Lift. Black. 2014 GMC 2500HD 4x4 Duramax Crewcab

03-06-2003, 09:53 PM	#10
79BIG10 I'm back with 2nd truck! Join Date: Feb 2002 Location: Texas Posts: 3,775	Here's a sized down size that I got from Mike Reeh awhile back. If you need a full size email me and I'll send it to you. Attached Images __________________ 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

03-09-2003, 12:02 AM	#11
Lil Greg Registered User Join Date: Feb 2003 Location: Mansfield,Tx Posts: 54	Ok everyone im going to try to dig into this mess monday and ill use the diagrams yall gave me hopfully ill get it done i just couldn't bring myself to work on it friday i was so nice i headed to the lake, well thanks for your help everyone.



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