65 Suburban Fuel Tank Sending Unit?

[RoyL]

http://www.brotherstrucks.com/prodin...number=GTS66PN

This is the sending unit that measures the amount of gas in your tank and relays the information to your gas gauge. BROTHERS sells only complete sending units that come with the float and gasket. This sending unit also can be used with the 67-72 blazer gas tank conversion so that you can use your stock fuel gauge (0-30 ohms).***This unit uses the lock ring if you have a screw in type it won't work**

I have stock tank and stock guages, is this the baby I need? have read about 0-30 ohms, 90 ohms . . . confused . . .

Thx,

Roy

[61_FL_Apache]

I looked at LMC and this is all they had. Not much info either on OHM's.

http://www.lmctruck.com/icatalog/cbe/full.aspx?Page=71

[jimmillac]

Hey RoyL. Are you trying to figure out if you really have a 30 Ohm gas guage? If I recall correctly, these old guages actually use a bimetal strip and heater circuit to move the guage with the heater current being limited by the resistance of the sending unit. I think it would be pretty tough to get an accurate resistance measurement of the fuel guage with an ohmeter because the heater resistance is going to change as the element heats up. What you can do though, is go to radio shack, get 3 10 Ohm power resistors (part number 271-132). Wire the three resistors in series (end to end). For this little test, you can just twist the wire ends together. Then, connect one free end of the series resistor to the connector that usually hooks to your fuel sender. Connect the other free end to a good ground. Turn your key on. If your fuel guage is truly 30 ohms, it will read 1/2 full +/- a little bit. Does that help?

[RoyL]

Originally Posted by RoyL

http://www.brotherstrucks.com/prodin...number=GTS66PN

I have stock tank and stock gauges, is this the baby I need? have read about 0-30 ohms, 90 ohms . . . confused . . .

Thx,

Roy

I read in a few different Chevy forums, where it was stated that GM fuel gauges went from 30 to 90 ohms in 1965??? Then I see someone else contradict that.

from Nova site: "1965 was still 30 ohm...... '66 started with 90 ohm......

Answers from Brothers on the sending unit, Item: GTS66PN. They say 65 is 30 ohms. So I should be OK with their unit . . .

Q1. I have a 1965 Suburban with stock tank and fuel gauge, will this sending
unit work with my gauge. I have no idea if it's 0-30 ohms . . .
A1, Brothers: "The sending unit will work on a 65 suburban it is 0-30 ohms."

Q2. Does it come with a new lock collar?
A2, Brothers: "Yes the lock ring is included."

Q3. Does it have a threaded fuel connection like shown in the picture? If
so, what size fitting? I have a rubber hose connection now.
A3, Brothers: "Yes it has the threaded pickup tube on the top of the sending unit, 3/8 inch."

I also need new rubber filler hose to the tank, haven't seen that listed anywhere. Looks to be 2 different sizes on each end?

Thx,
Roy

[protrash64]

I changed mine and it worked fine; 0-30 ohm, pretty sure.

[jbgroby]

I've been down this road already.

IF you are going back with stock "Antique/Restored" or the older gauges as oem, you will and can use 30 ohm. If you use modern after market guages you will need to have the sending unit's resisitor change to a 90 ohm. You can buy the OEM sending unit and ship it off to have the reisitor changed.

Dolphin Gauges "Use to do the changeout" but layers got involved and an issue of liablilty came up so they will no longer do it. They was a guy on the Stovebolt page who advertised to do it. Mayorga?

[RoyL]

Originally Posted by RoyL

I also need new rubber filler hose to the tank, haven't seen that listed anywhere. Looks to be 2 different sizes on each end?

Thx,
Roy

1 3/8" fuel filler hose? I checked and both ends are 1 3/8", just looked different. If you can find it local, NAPA, boat place, etc, Good for you. NAPA here only has 1.5" ID and up. Oreilly only has a 3 ft section with a bend in it. Gates - Gasoline Filler Neck Hose, Part # 24702

http://www.oreillyauto.com/site/c/de...0065&ppt=C0075


Truck Shop 1 3/8" I.D. fuel hose. 63-107094 63-72 per foot . . . . . . . . . . . .$ 13.00 ft.

http://www.truckandcarshop.com/trucks60_72/t60_078.html

Still working on the sending unit, will check the ohms range on it to verify it's 0-30.
Roy

[Corts60]

Great link on the fuel hose! I'll be looking for that myself here by the end of the week.

[RoyL]

Originally Posted by jimmillac

Hey RoyL. Are you trying to figure out if you really have a 30 Ohm gas guage? If I recall correctly, these old guages actually use a bimetal strip and heater circuit to move the guage with the heater current being limited by the resistance of the sending unit. I think it would be pretty tough to get an accurate resistance measurement of the fuel guage with an ohmeter because the heater resistance is going to change as the element heats up. What you can do though, is go to radio shack, get 3 10 Ohm power resistors (part number 271-132). Wire the three resistors in series (end to end). For this little test, you can just twist the wire ends together. Then, connect one free end of the series resistor to the connector that usually hooks to your fuel sender. Connect the other free end to a good ground. Turn your key on. If your fuel guage is truly 30 ohms, it will read 1/2 full +/- a little bit. Does that help?

With the sender out of the tank, i checked the resistance across the 2 terminals, while moving the float, but got no reading, no connectivity between the two. So cant confirm the sender, how to check the gauge out of the truck?
Thx,
Roy
Posted via Mobile Device

[jimmillac]

Hi Roy,
Sorry about my first long winded response. Obviously I didn't understand your question. Your ohmeter should indicate close to a dead short with the float up as high as it will go (full tank position). If you aren't seeing any resistance on your ohmeter I suspect your sender is toast. To check your guage, if it is still in the truck, ground the wire that normally connects to the sender and turn the key on. Your guage should move to full. This should be a tan wire if my diagram is correct an you have factory wiring. With the guage out of the truck, you should be able to connect it across your battery and get a full tank indication. The terminal that had the pink wire on it should go to the + battery terminal and the terminal that had the tan wire on it will connect to the - battery terminal. All you are looking for is the needle to move. If it does, your guage is ok. for the whole circuit, again if my diagram is correct, the positive pink wire originates at the "R" terminal on your starter solenoid, goes through the firewall connector, and then splits to several pink wires in the cab with one of those going to the gas guage terminal. So, with the key on, you should be able to measure 12V at this terminal. The tan wire goes straight to your sensor. Hope this helps, Les

[jimmillac]

Oops... not enough coffee yet I guess... the pink wire originates at the ignition switch and is hot when the key is on. Sorry 'bout that.

[RoyL]

Les,
Thanks. The gauge and dash cluster are out of the truck. Was able to get the gas gauge needle to move with battery across the terminals, so believe the gauge is good. Not sure how to bench check the gauge out of the truck to see if it’s a 30 ohm . . . I have an Autowire harness installed (well mostly). The gauges were not hooked up when I bought the truck, so not sure if it worked or not.

HOWEVER, I cleaned up my old crusty sender and did get it to read from about 34 ohms down to near 0 moving the float, so the 0-30 ohm sender from Brothers should work.

On the changeover from 30 to 90 ohms by GM, guy at Brothers said GM didn't change from 30 to 90 ohms until '67. And from others here, jbgroby and protrash64, looks like that may be true. I did run across a thread somewhere that said GM cars may have went to 90 ohm earlier, but the trucks not till 67 . . .
I will let ya’ll know once I get the sender installed and checked out.
Thanks to all, the simple stuff ain't so simple . . . !
Roy

[erock805]

Roys right. 67 and up are the 90 ohm. Trying to get the stock gauge to work on my square suburban tank for my 64 pu.

[RoyL]

Originally Posted by RoyL

Answers from Brothers on the sending unit, Item: GTS66PN. They say 65 is 30 ohms. So I should be OK with their unit . . .

Q1. I have a 1965 Suburban with stock tank and fuel gauge, will this sending
unit work with my gauge. I have no idea if it's 0-30 ohms . . .
A1, Brothers: "The sending unit will work on a 65 suburban it is 0-30 ohms."

Q2. Does it come with a new lock collar?
A2, Brothers: "Yes the lock ring is included."

Q3. Does it have a threaded fuel connection like shown in the picture? If
so, what size fitting? I have a rubber hose connection now.
A3, Brothers: "Yes it has the threaded pickup tube on the top of the sending unit, 3/8 inch."

Thx,
Roy

I got a replacement sending unit from Brothers yesterday.

It did NOT have a lock ring!! I contacted them and they said it should have and are sending me one. Another 3-4 days to get it.

And it comes just like the original on the outlet line, it is not threaded like shown in the picture in their catalog.



yes, that is bailing wire holding the screen on the old one . . .


roy

[RoyL]

Update, got the gas tank cleaned out, new sending unit, new fuel filler hose, rewired teh sending unit, dash gauges hooked back up, a few gallons in the tank. Got here running again. Guage is reading about 1/4 full, I put in about 4 gallons, so looks pretty accurate.

One issue I ran into was the tank got pressured after I put the cap on, and was pushing gas out of the carb lines. I guess I need a vented cap. Got one from parts store, old one was rusted, bad gasket.

[ogsRULE]

This old thread is helpful to figure out what to do for the sending unit in my (I think to be) 1960 suburban gas tank. This is the screw type not lock ring and I am not really finding this at any of the usual places. Wondering if a universal type might work. Does anyone have any advice here?

Thanks,

Scottie.

[tincan1966]

I went to my local O'Reilly's and bought an Equus brand universal sender 0-30 ohm. Cost about $30. Works just fine with the stock gauge. Just follow the instructions closely on setting the depth and swing arm length.

You may need to make a sheet metal cover for the original hole, then install the new sender in the cover, as the new one may be a bit smaller diameter and most aftermarket are 5 hole.