Universal sending unit - The 1947 - Present Chevrolet & GMC Truck Message Board Network

JointTech · 03-18-2013, 04:54 PM

I have a saddletank that has a sending unit on it. When I got the truck there was a valve in the cab to switch between main and aux tank but there was no additional fuel gauge and the dash gauge obviously was connected to the main sending unit.

So I pulled the saddle tank out to have it cleaned and sealed so I can use it in place of the behind the seat firebomb.

when I took it in the guy said ill need a new sending unit. its pretty crusty.

Can I get just any universal unit or do a need a certain ohms to make it work with the factory fuel gauge?

The sending unit has the same retaining clip setup as the normal tanks. Is that part "keepable" and the universals connect inside to it? Or do I have to find a universal with the same locking nut dohickey on it?

JointTech · 03-25-2013, 06:33 PM

Got my aux tank cleaned and sealed and he went ahead and cleaned and painted the outside for me!!

So now to find a sending unit / fuel pickup combo unit.
Has anybody ever seen a universal?

**john** · 03-25-2013, 06:38 PM

I believe they are 90 ohm senders.

JointTech · 03-25-2013, 06:40 PM

I found this. It looks the same but mine uses screws to hold it in the tank and this one has a lock ring like the OE tanks. wonder if I can just screw it in.

doh forgot the link
http://www.summitracing.com/parts/gm...del/c10-pickup

**Ol Blue K20** · 03-25-2013, 06:51 PM

Stewart Warner 90 ohm sender should work, they screw down, just check dia.

JointTech · 03-25-2013, 06:55 PM

ill check on those. thanks

JointTech · 03-25-2013, 06:58 PM

http://www.partdeal.com/gauges/sende...-90-ohm-1.html

found that but it doesnt have the pickup tube. Ill keep digging.

**Ol Blue K20** · 03-25-2013, 07:40 PM

HMM.... my aux tank doesn't pick up from the sender hole. I'm sure they make one though check Summit

JointTech · 03-25-2013, 07:48 PM

im wondering if I can get a universal and use a bulkhead fitting for the pickup tube. Just drill an extra hole in the top of the sending unit plate and rig up some tube.

or maybe ill keep looking haha

**Ol Blue K20** · 03-25-2013, 07:52 PM

I wonder if yours is the factory/dealer installed unit. Mine are aftermarket

JointTech · 03-25-2013, 07:54 PM

interesting. I was told aux tanks are all dealer or aftermarket.

JointTech · 03-25-2013, 08:00 PM

hey hey. found this. http://67-72chevytrucks.com/vboard/s...d.php?t=363854
wish I had my spid but it mentions the tank switcher beside the seatbelt which is where I had mine. And i have a hole in my dash which i now think is for the switch to change between sending units.
now that is cool.. 2 tanks using the same gauge.

So now I know(think) its a factory tank.
maybe I can find the sender/pickup.
thanks for pointing me there.

**Ol Blue K20** · 03-25-2013, 08:07 PM

No problem, you should look up under the dash and see if the switch harness is still there. I know the switches pop up in the parts board now and then. I don't know if the switches are still made or repoped

SS Tim · 03-25-2013, 09:45 PM

There were factory installed aux tanks. Either a behind the axle N18 or a driver's side forward under bed NL2. These would be on your SPID. Aftermarket and dealer sold/installed tanks are more often found with through bedside filler doors or wheel well fillers.
Here are a couple of pictures to get you started.

The entire NL2 tank installation is covered in the assembly manual.

The sender picture is the factory NL2 aux tank sender and it is application specific.

We also hashed a lot out on a WTB thread of Jockos that is worth reading through.
http://67-72chevytrucks.com/vboard/s...d.php?t=560607

JointTech · 03-25-2013, 09:52 PM

so i need a AC 6428850. mine is jsut like the blue truck and the service manual looks just like my tank in the pic above. !!
thanks.
now google comes up with nothing on a 6428850. but i have some place to start at least.

SS Tim · 03-25-2013, 10:10 PM

IIRC livrat found that one on ebay and it is not for sale.

SS Tim · 03-25-2013, 10:14 PM

Most aux tanks are saddle tanks like these. This is a Demco wheel well filler kit ad from the Silverbook.

JointTech · 03-25-2013, 10:15 PM

ok ill keep looking for something universal I can adapt. not trying to be correct, just want it to work.

JointTech · 03-25-2013, 11:19 PM

ah. they couldnt have made it so easy that its the same sending unit as the 67-71 Blazer/suburban? Looks dang close to mine and would have the right ohms.
I also see that 60-66 trucks seem to use the same style but would be only 30 ohm.

http://www.ebay.com/itm/54-55-56-57-...9d8309&vxp=mtr

http://www.brotherstrucks.com/prodin...number=GTS6972

http://www.classicparts.com/1967-72-...tinfo/23-534/#

MARKDTN · 01-21-2014, 02:05 PM

OP may have solved his problem, but Isspro makes a good quality aftermarket sender.

http://isspro.mybigcommerce.com/fuel-level-senders/

you can search around and find what you need. I have bought at least 2 for boats through them.

03-18-2013, 04:54 PM	#1
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Universal sending unit I have a saddletank that has a sending unit on it. When I got the truck there was a valve in the cab to switch between main and aux tank but there was no additional fuel gauge and the dash gauge obviously was connected to the main sending unit. So I pulled the saddle tank out to have it cleaned and sealed so I can use it in place of the behind the seat firebomb. when I took it in the guy said ill need a new sending unit. its pretty crusty. Can I get just any universal unit or do a need a certain ohms to make it work with the factory fuel gauge? The sending unit has the same retaining clip setup as the normal tanks. Is that part "keepable" and the universals connect inside to it? Or do I have to find a universal with the same locking nut dohickey on it? __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread

03-25-2013, 06:33 PM	#2
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Universal sending unit Got my aux tank cleaned and sealed and he went ahead and cleaned and painted the outside for me!! So now to find a sending unit / fuel pickup combo unit. Has anybody ever seen a universal? __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread

03-25-2013, 06:38 PM	#3
john member #16 Join Date: Dec 1999 Location: Yuba City Ca. Posts: 3,618	Re: Universal sending unit I believe they are 90 ohm senders. __________________ john http://67-72chevytrucks.com/vboard/showgroups.php board vendors http://www.flickr.com/photos/1745471...7602865984234/

03-25-2013, 06:40 PM	#4
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Universal sending unit I found this. It looks the same but mine uses screws to hold it in the tank and this one has a lock ring like the OE tanks. wonder if I can just screw it in. doh forgot the link http://www.summitracing.com/parts/gm...del/c10-pickup __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread Last edited by JointTech; 03-25-2013 at 06:55 PM.

03-25-2013, 06:51 PM	#5
Ol Blue K20 Proprietor of Dale's Corner Join Date: Nov 2012 Location: Vacaville , CA Posts: 16,242	Re: Universal sending unit Stewart Warner 90 ohm sender should work, they screw down, just check dia. __________________ "Some Days Chickens And Some Days Feathers" Dale XNGH ECV Sam Brannan 1004 R.I.P. 67ChevyRedneck R.I.P. Grumpy Old Man R.I.P. FleetsidePaul

03-25-2013, 06:55 PM	#6
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Universal sending unit ill check on those. thanks __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread

03-25-2013, 06:58 PM	#7
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Universal sending unit http://www.partdeal.com/gauges/sende...-90-ohm-1.html found that but it doesnt have the pickup tube. Ill keep digging. __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread

03-25-2013, 07:40 PM	#8
Ol Blue K20 Proprietor of Dale's Corner Join Date: Nov 2012 Location: Vacaville , CA Posts: 16,242	Re: Universal sending unit HMM.... my aux tank doesn't pick up from the sender hole. I'm sure they make one though check Summit __________________ "Some Days Chickens And Some Days Feathers" Dale XNGH ECV Sam Brannan 1004 R.I.P. 67ChevyRedneck R.I.P. Grumpy Old Man R.I.P. FleetsidePaul

03-25-2013, 07:48 PM	#9
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Universal sending unit im wondering if I can get a universal and use a bulkhead fitting for the pickup tube. Just drill an extra hole in the top of the sending unit plate and rig up some tube. or maybe ill keep looking haha __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread

03-25-2013, 07:52 PM	#10
Ol Blue K20 Proprietor of Dale's Corner Join Date: Nov 2012 Location: Vacaville , CA Posts: 16,242	Re: Universal sending unit I wonder if yours is the factory/dealer installed unit. Mine are aftermarket __________________ "Some Days Chickens And Some Days Feathers" Dale XNGH ECV Sam Brannan 1004 R.I.P. 67ChevyRedneck R.I.P. Grumpy Old Man R.I.P. FleetsidePaul

03-25-2013, 07:54 PM	#11
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Universal sending unit interesting. I was told aux tanks are all dealer or aftermarket. __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread

03-25-2013, 08:00 PM	#12
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Universal sending unit hey hey. found this. http://67-72chevytrucks.com/vboard/s...d.php?t=363854 wish I had my spid but it mentions the tank switcher beside the seatbelt which is where I had mine. And i have a hole in my dash which i now think is for the switch to change between sending units. now that is cool.. 2 tanks using the same gauge. So now I know(think) its a factory tank. maybe I can find the sender/pickup. thanks for pointing me there. __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread

03-25-2013, 08:07 PM	#13
Ol Blue K20 Proprietor of Dale's Corner Join Date: Nov 2012 Location: Vacaville , CA Posts: 16,242	Re: Universal sending unit No problem, you should look up under the dash and see if the switch harness is still there. I know the switches pop up in the parts board now and then. I don't know if the switches are still made or repoped __________________ "Some Days Chickens And Some Days Feathers" Dale XNGH ECV Sam Brannan 1004 R.I.P. 67ChevyRedneck R.I.P. Grumpy Old Man R.I.P. FleetsidePaul

03-25-2013, 09:45 PM	#14
SS Tim Registered User Join Date: Aug 2010 Location: Edwards, CA Posts: 7,503	Re: Universal sending unit There were factory installed aux tanks. Either a behind the axle N18 or a driver's side forward under bed NL2. These would be on your SPID. Aftermarket and dealer sold/installed tanks are more often found with through bedside filler doors or wheel well fillers. Here are a couple of pictures to get you started. The entire NL2 tank installation is covered in the assembly manual. The sender picture is the factory NL2 aux tank sender and it is application specific. We also hashed a lot out on a WTB thread of Jockos that is worth reading through. http://67-72chevytrucks.com/vboard/s...d.php?t=560607 Attached Images __________________ Thanks, Tim * VIN/Model Decoders * Power Team Charts (engine/transmission/gear ratio) * Post Your Pickup SPID Blazer SPID Suburban/Panel SPID * RTFM ... Read The Factory Manuals... download 'em here Highlanders Do you have a 1972 Plaid Pickup? Plaid Blazer ** Plaid Suburban

03-25-2013, 09:52 PM	#15
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Universal sending unit so i need a AC 6428850. mine is jsut like the blue truck and the service manual looks just like my tank in the pic above. !! thanks. now google comes up with nothing on a 6428850. but i have some place to start at least. __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread



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03-25-2013, 10:10 PM	#16
SS Tim Registered User Join Date: Aug 2010 Location: Edwards, CA Posts: 7,503	Re: Universal sending unit IIRC livrat found that one on ebay and it is not for sale. __________________ Thanks, Tim * VIN/Model Decoders * Power Team Charts (engine/transmission/gear ratio) * Post Your Pickup SPID Blazer SPID Suburban/Panel SPID * RTFM ... Read The Factory Manuals... download 'em here Highlanders Do you have a 1972 Plaid Pickup? Plaid Blazer ** Plaid Suburban

03-25-2013, 10:14 PM	#17
SS Tim Registered User Join Date: Aug 2010 Location: Edwards, CA Posts: 7,503	Re: Universal sending unit Most aux tanks are saddle tanks like these. This is a Demco wheel well filler kit ad from the Silverbook. Attached Images __________________ Thanks, Tim * VIN/Model Decoders * Power Team Charts (engine/transmission/gear ratio) * Post Your Pickup SPID Blazer SPID Suburban/Panel SPID * RTFM ... Read The Factory Manuals... download 'em here Highlanders Do you have a 1972 Plaid Pickup? Plaid Blazer ** Plaid Suburban Last edited by SS Tim; 03-25-2013 at 10:22 PM. Reason: correcting a double post

03-25-2013, 10:15 PM	#18
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Universal sending unit ok ill keep looking for something universal I can adapt. not trying to be correct, just want it to work. __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread

03-25-2013, 11:19 PM	#19
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Universal sending unit ah. they couldnt have made it so easy that its the same sending unit as the 67-71 Blazer/suburban? Looks dang close to mine and would have the right ohms. I also see that 60-66 trucks seem to use the same style but would be only 30 ohm. http://www.ebay.com/itm/54-55-56-57-...9d8309&vxp=mtr http://www.brotherstrucks.com/prodin...number=GTS6972 http://www.classicparts.com/1967-72-...tinfo/23-534/# __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread

01-21-2014, 02:05 PM	#20
MARKDTN Registered User Join Date: Jan 2011 Location: Chattanooga, TN Posts: 2,159	Re: Universal sending unit OP may have solved his problem, but Isspro makes a good quality aftermarket sender. http://isspro.mybigcommerce.com/fuel-level-senders/ you can search around and find what you need. I have bought at least 2 for boats through them. __________________ '83 K20-TPI '73 C10 '79 C10-ex-diesel(SOLD) '07 Tahoe(Son driving) '14 Suburban-DD '71 C10-current project

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