which sending unit? im lost - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sixtyeightchevykid · 10-22-2011, 01:59 PM

hello, the other day i got in my truck and started it and noticed the gas gauge was pointing way past full, in about the 3 o'clock position, and so i did some research and troubleshooting and found that the gauge is fine the problem is the sending unit in the tank. so i went to my local parts stores and they cant get a sending unit, so i check lmc, and classic industries, they both have more than one sending unit listed. i looked at the one in my truck and it has a threded brass peice on the end where the line from the floor goes into it, and what i have found is that, that style is for a v8, i have a 250 inline 6 in my truck, so i need to know which to order? any info and input will be appriciated , thanks

http://www.classicindustries.com/tru...s/6428361.html
http://www.classicindustries.com/tru...s/6428362.html

PanelDeland · 10-22-2011, 02:11 PM

You need to know how the truck(at least the fuel sending unit was equipted) The 6 cyl sending unit and guage are one ohms.The V8 is another.They need to match for it to work correctly.
Grounds and other elect stuff can also cause problems.
I've only seen the sending units offered by vendors.Most of them should be able to tell which you need.Best bet is to contact one of the BB vendors and they will get you fixed up.

Newtz67 · 10-22-2011, 02:22 PM

Check out the truck shop. They specify year and engine size. I thought they were all 90 ohm. But I could be wrong...There website is Truckandcarshop.com

sixtyeightchevykid · 10-22-2011, 02:27 PM

if the gauges were matched to the engine and sending unit, like you are saying the v8 and 6cyl are different, then whay is there only one gauge offered? not one for v8 and one for 6cyl.

sixtyeightchevykid · 10-22-2011, 03:33 PM

im thinking just get the one that matches the one that is currently in my truck that way i wont have to switch out the gas line that connects to the sending unit and goes through the floor..

**JJorgensen52** · 10-22-2011, 03:37 PM

Unless I am mistaken, the pickup line on the I6 trucks is 5/16" and the V8 trucks is 3/8", and that is where your difference is. All GM sending units are 90ohms so far as I know

sixtyeightchevykid · 10-22-2011, 03:52 PM

the first pic is of the one that classic industries says is for a v8 the second pic is of the one they say is for a 6cyl. the one currently in my truck looks like the first pic, the one for the v8,

Hubscrub · 10-22-2011, 05:17 PM

I ordered this sender from classic parts of america for our 67 that was orginal 6cyl. 5/16 line truck. replaced orginal exactly. just insalled it last week. the V-8 has a larger line.

lil hoodlum · 10-22-2011, 05:23 PM

Quote:

Originally Posted by sixtyeightchevykid

if the gauges were matched to the engine and sending unit, like you are saying the v8 and 6cyl are different, then whay is there only one gauge offered? not one for v8 and one for 6cyl.

I have allways wondered about the same thing. There is only one gauge offered!

Keith

sixtyeightchevykid · 10-22-2011, 05:35 PM

Hubscrub, that looks just like what i need, do you have a part number?

**VetteVet** · 10-22-2011, 06:08 PM

Did you ground the tan sending unit wire that goes to the sender terminal and watch the gauge to see if it drops to empty with the key on, and did you measure the resistance between the center terminal on the sender and the flange while you raise and lower the float arm. If you get zero to ninety ohms on the sender while doing that, your sender is ok, and the sender unit is not grounded to the frame.

sixtyeightchevykid · 10-22-2011, 06:27 PM

i did, the gauge went to dead empty, i dont have a dvom to test elecrical stuff.. so if i run a wire from a good ground to the sender and it works then its just a ground?

sixtyeightchevykid · 10-22-2011, 06:40 PM

i just went out and took a wire and hooked it onto a known good ground and took the other end and put it on multiple spots on the sending unit, there was no change in the gauge reading.

**VetteVet** · 10-22-2011, 08:25 PM

Quote:

Originally Posted by sixtyeightchevykid

i did, the gauge went to dead empty, i dont have a dvom to test elecrical stuff.. so if i run a wire from a good ground to the sender and it works then its just a ground?

If you have the sender installed in the tank and you run a good ground to the sender mounting flange and the gauge works, then it's just a ground. If it doesn't work then it is most likely the variable resistor on the float arm. Dvoms don't cost much and they are one of the best tools to have on vehicles.

**Tim Christian** · 10-22-2011, 08:30 PM

67-71 6 cylinder 5/16 line
67-72 V-8 3/8 line
72 auto 2-lines
72 manual 1-line

All of them 90 ohms

**VetteVet** · 10-22-2011, 08:33 PM

Quote:

Originally Posted by sixtyeightchevykid

i just went out and took a wire and hooked it onto a known good ground and took the other end and put it on multiple spots on the sending unit, there was no change in the gauge reading.

Check the metal strip between the sender wire terminal and the float arm ( see the picture posted by Hubscrub) and see if it has come off.

treveiger · 10-22-2011, 10:15 PM

You can have a v8 with the 5/16 inch fuel line. I just called Maine's truck parts an they helped me out with what I needed!
Posted via Mobile Device

Hubscrub · 10-22-2011, 11:24 PM

part #is 23-529 from classic parts of america $29.95http://www.classicparts.com/1967-71-...ctinfo/23-529/

sixtyeightchevykid · 10-23-2011, 07:55 AM

vettevet, i will be getting a dvom one of these days soon hopefully. there have been other times that one would have come in handy.

Hubscrub, did the sender you ordered come with a new gasket?

Hubscrub · 10-23-2011, 08:24 AM

Quote:

Originally Posted by sixtyeightchevykid

Hubscrub, did the sender you ordered come with a new gasket?

yes

sixtyeightchevykid · 10-23-2011, 10:37 AM

ok i ordered the one from classic parts, the same one as Hubscrub, and a new lock ring. thank you all for your help and input.

Longhorn Man · 10-23-2011, 10:44 AM

2 bbl small blocks also got the 5/16ths line.

PanelDeland · 10-23-2011, 11:54 AM

I stand "Schooled" I knew there was a difference,I just couldn't remember what.

Andy4639 · 10-23-2011, 01:19 PM

As far as sending units go Chevy uses 2 of them. 0-90 and 90-0. Our factory trucks use the 0-90 and later models use the 90-0. My 71 with TPI and a 93 Chevy Surburban tank is on the 90-0 setting per SpeedHut gauges.

10-22-2011, 01:59 PM	#1
sixtyeightchevykid Registered User Join Date: Jan 2010 Location: Stillwater, Oklahoma Posts: 194	which sending unit? im lost hello, the other day i got in my truck and started it and noticed the gas gauge was pointing way past full, in about the 3 o'clock position, and so i did some research and troubleshooting and found that the gauge is fine the problem is the sending unit in the tank. so i went to my local parts stores and they cant get a sending unit, so i check lmc, and classic industries, they both have more than one sending unit listed. i looked at the one in my truck and it has a threded brass peice on the end where the line from the floor goes into it, and what i have found is that, that style is for a v8, i have a 250 inline 6 in my truck, so i need to know which to order? any info and input will be appriciated , thanks http://www.classicindustries.com/tru...s/6428361.html http://www.classicindustries.com/tru...s/6428362.html __________________ 1968 chevy c10 lwb, 250 inline6, 4 speed,

10-22-2011, 02:11 PM	#2
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,992	Re: which sending unit? im lost You need to know how the truck(at least the fuel sending unit was equipted) The 6 cyl sending unit and guage are one ohms.The V8 is another.They need to match for it to work correctly. Grounds and other elect stuff can also cause problems. I've only seen the sending units offered by vendors.Most of them should be able to tell which you need.Best bet is to contact one of the BB vendors and they will get you fixed up. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

10-22-2011, 02:22 PM	#3
Newtz67 Registered User Join Date: Mar 2010 Location: A t w a t e r, Ca Posts: 1,201	Re: which sending unit? im lost Check out the truck shop. They specify year and engine size. I thought they were all 90 ohm. But I could be wrong...There website is Truckandcarshop.com __________________ My '67 short wide Our '68 Burb My '04 Z71 The '54 Belair The '69 Cadillac

10-22-2011, 02:27 PM	#4
sixtyeightchevykid Registered User Join Date: Jan 2010 Location: Stillwater, Oklahoma Posts: 194	Re: which sending unit? im lost if the gauges were matched to the engine and sending unit, like you are saying the v8 and 6cyl are different, then whay is there only one gauge offered? not one for v8 and one for 6cyl. __________________ 1968 chevy c10 lwb, 250 inline6, 4 speed,

10-22-2011, 03:33 PM	#5
sixtyeightchevykid Registered User Join Date: Jan 2010 Location: Stillwater, Oklahoma Posts: 194	Re: which sending unit? im lost im thinking just get the one that matches the one that is currently in my truck that way i wont have to switch out the gas line that connects to the sending unit and goes through the floor.. __________________ 1968 chevy c10 lwb, 250 inline6, 4 speed,

10-22-2011, 03:37 PM	#6
JJorgensen52 Simple? What's simple? Join Date: Apr 2007 Location: Southeast CT Posts: 1,472	Re: which sending unit? im lost Unless I am mistaken, the pickup line on the I6 trucks is 5/16" and the V8 trucks is 3/8", and that is where your difference is. All GM sending units are 90ohms so far as I know __________________ CURRENT '50 GMC 100 shortbed Gen IV 4.8 LS - 4L65E (Secret truck, Shhh!!!) Build '63 Buick Wildcat Coupe 401ci Nailhead (Very much in pieces) Photos '66 Impala SS convertible 327-QJet-glide (4 speed swap one of these days...) Photos '69 CST/10 4x4 SWB Stepper 350 2bbl - NV4500/NP241C (Broken Truck!) '72 Sierra Grande 2WD LWB fleetside 350-TH350 Refresh '99 K2500 Silverado RCLB 5.7 Vortec - NV4500/NP241C (Daily) '99 K2500 Suburban 7.4 Vortec - NV4500/NP246 (still working out the bugs) SOLD '71 Custom/10 2WD LWB fleetside - '72 GMC K/3500 Dually (Sold to redryder)

10-22-2011, 03:52 PM	#7
sixtyeightchevykid Registered User Join Date: Jan 2010 Location: Stillwater, Oklahoma Posts: 194	Re: which sending unit? im lost the first pic is of the one that classic industries says is for a v8 the second pic is of the one they say is for a 6cyl. the one currently in my truck looks like the first pic, the one for the v8, Attached Images __________________ 1968 chevy c10 lwb, 250 inline6, 4 speed,

10-22-2011, 05:17 PM	#8
Hubscrub Cruzin Join Date: Dec 2009 Location: on the road Posts: 2,835	Re: which sending unit? im lost I ordered this sender from classic parts of america for our 67 that was orginal 6cyl. 5/16 line truck. replaced orginal exactly. just insalled it last week. the V-8 has a larger line. Attached Images __________________ Lime Wife's 67https://www.google.com/url?sa=t&rct=...wZEMODaS2d94u8 Back to the Fifties 59 https://www.google.com/url?sa=t&rct=...NAeStpydfrcj_U Proverbs 3:5,6 "Thanks to the Interstate Highway System, it is now possible to travel across the country from coast to coast without seeing anything."Charles Kuralt In memory of our first baby daughter, daddy and mommy love you. Danica Grace 6/26/14

10-22-2011, 05:35 PM	#10
sixtyeightchevykid Registered User Join Date: Jan 2010 Location: Stillwater, Oklahoma Posts: 194	Re: which sending unit? im lost Hubscrub, that looks just like what i need, do you have a part number? __________________ 1968 chevy c10 lwb, 250 inline6, 4 speed,

10-22-2011, 06:08 PM	#11
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,719	Re: which sending unit? im lost Did you ground the tan sending unit wire that goes to the sender terminal and watch the gauge to see if it drops to empty with the key on, and did you measure the resistance between the center terminal on the sender and the flange while you raise and lower the float arm. If you get zero to ninety ohms on the sender while doing that, your sender is ok, and the sender unit is not grounded to the frame. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

10-22-2011, 06:27 PM	#12
sixtyeightchevykid Registered User Join Date: Jan 2010 Location: Stillwater, Oklahoma Posts: 194	Re: which sending unit? im lost i did, the gauge went to dead empty, i dont have a dvom to test elecrical stuff.. so if i run a wire from a good ground to the sender and it works then its just a ground? __________________ 1968 chevy c10 lwb, 250 inline6, 4 speed,

10-22-2011, 06:40 PM	#13
sixtyeightchevykid Registered User Join Date: Jan 2010 Location: Stillwater, Oklahoma Posts: 194	Re: which sending unit? im lost i just went out and took a wire and hooked it onto a known good ground and took the other end and put it on multiple spots on the sending unit, there was no change in the gauge reading. __________________ 1968 chevy c10 lwb, 250 inline6, 4 speed,

10-22-2011, 08:30 PM	#15
Tim Christian Senior Member Join Date: Dec 1999 Location: TN/VA Posts: 6,388	Re: which sending unit? im lost 67-71 6 cylinder 5/16 line 67-72 V-8 3/8 line 72 auto 2-lines 72 manual 1-line All of them 90 ohms

10-22-2011, 10:15 PM	#17
treveiger Senior Member Join Date: Jul 2010 Location: South Dakota Posts: 4,097	Re: which sending unit? im lost You can have a v8 with the 5/16 inch fuel line. I just called Maine's truck parts an they helped me out with what I needed! Posted via Mobile Device __________________ 1969 Chevy c20(Miss Hackjob)

10-22-2011, 11:24 PM	#18
Hubscrub Cruzin Join Date: Dec 2009 Location: on the road Posts: 2,835	Re: which sending unit? im lost part #is 23-529 from classic parts of america $29.95http://www.classicparts.com/1967-71-...ctinfo/23-529/ __________________ Lime Wife's 67https://www.google.com/url?sa=t&rct=...wZEMODaS2d94u8 Back to the Fifties 59 https://www.google.com/url?sa=t&rct=...NAeStpydfrcj_U Proverbs 3:5,6 "Thanks to the Interstate Highway System, it is now possible to travel across the country from coast to coast without seeing anything."Charles Kuralt In memory of our first baby daughter, daddy and mommy love you. Danica Grace 6/26/14



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10-23-2011, 07:55 AM	#19
sixtyeightchevykid Registered User Join Date: Jan 2010 Location: Stillwater, Oklahoma Posts: 194	Re: which sending unit? im lost vettevet, i will be getting a dvom one of these days soon hopefully. there have been other times that one would have come in handy. Hubscrub, did the sender you ordered come with a new gasket? __________________ 1968 chevy c10 lwb, 250 inline6, 4 speed,

10-23-2011, 10:37 AM	#21
sixtyeightchevykid Registered User Join Date: Jan 2010 Location: Stillwater, Oklahoma Posts: 194	Re: which sending unit? im lost ok i ordered the one from classic parts, the same one as Hubscrub, and a new lock ring. thank you all for your help and input. __________________ 1968 chevy c10 lwb, 250 inline6, 4 speed,

10-23-2011, 10:44 AM	#22
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: which sending unit? im lost 2 bbl small blocks also got the 5/16ths line.

10-23-2011, 11:54 AM	#23
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,992	Re: which sending unit? im lost I stand "Schooled" I knew there was a difference,I just couldn't remember what. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

10-23-2011, 01:19 PM	#24
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: which sending unit? im lost As far as sending units go Chevy uses 2 of them. 0-90 and 90-0. Our factory trucks use the 0-90 and later models use the 90-0. My 71 with TPI and a 93 Chevy Surburban tank is on the 90-0 setting per SpeedHut gauges. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

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