aftermarket fuel gauge

[SeanPaintsFlames]

I got Dolphin gauges, they came with a new sender, but the sender isn't one that has the fuel pickup line in it like the factory one. Has anyone been able to use the original sender with the new gauge? Mine never worked to begin with, so I wouldn't know for sure whether or not they were compatible just by hooking it up. Thanks!!

[62 short step]

I have Dolphin gauges too, I know the sending unit that comes with it doesn't work with our in cab tanks. I just purchased a new modified sending unit from a guy on another board that makes them work with the 90 ohm gaues. I should have it by the end of the week. I'll let you know how it works.

[greg64]

On my 64, the sender is 0-30 ohms. But, on later Chevys they went to 0-90 ohm range (my 77 is 90 ohm). Clearly the sender has to match the gauge, so I'd check if your new Dolphin is 0-90 ohm.

To test your original sender, hook an ohmmeter between ground and the tank sender wire. When the float is all the way down (empty), it should read 0 ohms. When the float is all the way up (full), it should read 30 or 90 ohms.

[slepysal]

You are all correct the senders ohm's must match the gauge,but our original senders have the fuel pick up built into it.
I used an automeeter 0-30 ohm gauge in a home fabed pannel works great.

[SeanPaintsFlames]

Okay, I looked at the original again, and looked at the new one, and I think that both have the bolt-through-the-bottom sender on the mounting plate. I'm going to try to take the old plate and mount the new sender on it and see if that works. The new one by itself will for sure not work. As soon as I wired it up it shot way past full tank.

[vin63]

Originally Posted by SeanPaintsFlames

Okay, I looked at the original again, and looked at the new one, and I think that both have the bolt-through-the-bottom sender on the mounting plate. I'm going to try to take the old plate and mount the new sender on it and see if that works. The new one by itself will for sure not work. As soon as I wired it up it shot way past full tank.

You may have already figured out your sending unit/fuel gauge interface, but just in case you haven't, I offer brand new modified OE gas tank sending units for the 60-66 GM trucks with the stock gas tanks to work with the 0-90 ohm aftermarket fuel gauges. I've done several locally and a few recently for my friends, and I just did one for 62 Short Step. Let me know if you need one.

[61hawk]

Originally Posted by vin63

You may have already figured out your sending unit/fuel gauge interface, but just in case you haven't, I offer brand new modified OE gas tank sending units for the 60-66 GM trucks with the stock gas tanks to work with the 0-90 ohm aftermarket fuel gauges. I've done several locally and a few recently for my friends, and I just did one for 62 Short Step. Let me know if you need one.

What I would like to see is just the opposite... 0-90 ohm sending unit in a stock original 0-30 ohm gauge. I'm taking out my original tank and replacing it with saddle tanks. The saddle tanks don't have the 5-screw sending unit openings, they have the lock-ring opening. All of the aftermarket 0-30 ohm sending units I've found need the 5-screw opening in the tank. What I need is someone who can rewire the gauge to 0-90 ohm specs.

[vin63]

Originally Posted by 61hawk

What I would like to see is just the opposite... 0-90 ohm sending unit in a stock original 0-30 ohm gauge. I'm taking out my original tank and replacing it with saddle tanks. The saddle tanks don't have the 5-screw sending unit openings, they have the lock-ring opening. All of the aftermarket 0-30 ohm sending units I've found need the 5-screw opening in the tank. What I need is someone who can rewire the gauge to 0-90 ohm specs.

Do you have photos of the sending units for the saddle tanks that you have/will be installing? I would also need to know the vertical length of the sending unit. It would be much more pratical to modify the sending unit's float assembly to a 0-30 ohm resistor.

[62 short step]

Like Vince said, I got one from him and it works excellent!

[SeanPaintsFlames]

I already figured it out, but thanks, though! I used the old top plate and pickup line with the new, but slightly-modified sender unit.

[61hawk]

Originally Posted by vin63

Do you have photos of the sending units for the saddle tanks that you have/will be installing? I would also need to know the vertical length of the sending unit. It would be much more pratical to modify the sending unit's float assembly to a 0-30 ohm resistor.

I'm probably going to be using these sending units. They're already 0-30 ohm, but the saddle tanks that are pre-made don't have the mounting openings for this style (they use the lock ring). I think I'm probably going to go with custom tanks, the guy at the restoration shop says he has a contact for a guy that can make them up for me at a reasonable price... I e-mailed him shortly after sending the last post.

[vin63]

Originally Posted by 61hawk

I'm probably going to be using these sending units. They're already 0-30 ohm, but the saddle tanks that are pre-made don't have the mounting openings for this style (they use the lock ring). I think I'm probably going to go with custom tanks, the guy at the restoration shop says he has a contact for a guy that can make them up for me at a reasonable price... I e-mailed him shortly after sending the last post.

Cool...sounds like you've got it covered. That will be a great tank conversion with lots of range. Good luck and post some photos of the tanks mounted.

[wild one]

Originally Posted by vin63

Do you have photos of the sending units for the saddle tanks that you have/will be installing? I would also need to know the vertical length of the sending unit. It would be much more pratical to modify the sending unit's float assembly to a 0-30 ohm
resistor.

Vin 63,

I mounted a 30 gallon fuel tank and 90ohm sender out of a 1977 blazer in my 1966 C10 panel truck over a year ago and have run the truck dry on more occasions than I care to admit too (I carry a small gas can in the back for such emergencies ). How do you modify the sending units float to 0-30 ohm, I have tried using inline resistors to "cut" the ohm load to get the factory 1966 30 ohm gauge to work with the 90 ohm sending unit. Needless to say I haven't quite perfected it! Any help/pictures on the subject would be greatly appreciated!

Thanks,
Pete

[vin63]

Originally Posted by wild one

Vin 63,

I mounted a 30 gallon fuel tank and 90ohm sender out of a 1977 blazer in my 1966 C10 panel truck over a year ago and have run the truck dry on more occasions than I care to admit too (I carry a small gas can in the back for such emergencies ). How do you modify the sending units float to 0-30 ohm, I have tried using inline resistors to "cut" the ohm load to get the factory 1966 30 ohm gauge to work with the 90 ohm sending unit. Needless to say I haven't quite perfected it! Any help/pictures on the subject would be greatly appreciated!

Thanks,
Pete

Hi Pete. There are a lot of 0-30 ohm sending units still available for the older applications. I would try to cross reference one that is similar in size and with the same collar mount to the one for your Blazer tank. I'm not as familiar with a reverse conversion, so I don't want to steer you in the wrong direction. Good luck.

[61hawk]

Originally Posted by vin63

Hi Pete. There are a lot of 0-30 ohm sending units still available for the older applications. I would try to cross reference one that is similar in size and with the same collar mount to the one for your Blazer tank. I'm not as familiar with a reverse conversion, so I don't want to steer you in the wrong direction. Good luck.

The problem I am having is the mounting style is different on the 0-30's and the 0-90's. All of the 0-30 ohm sending units I've found have the 5-screw style mount and the 0-90 ohm sending units have the drop-in style with the locking ring. All of the aftermarket tanks I've found have the locking ring style bung hole. The only option I can find to fix this is to put a plate in over the factory hole and drill a hole for the 5-screw style sending unit. Which if going that route, custom tanks can be found for close to the same price.

[Sensei]

After much research I figured out my existing 66 C10 unit was a 0-30 ohm and the new matching dolphin gauges only are made in the 0-90 ohm range, so not wanting to get a whole new set of gauges so they would all match I finally decided to just take the oem fuel sending unit out and mark the float center pivot on the inlet tube then carefuly cut the old sending unit off the tube. (don't pry it off or you will be welding up a hole in the tube as well) and then I took the new dolphin unit apart and tack welded it with the same center pivot line.
The dolphin unit actually welded in on the opposite side so i left the existing cut off tabs in place. Be carefull the cover the sending unit openings so no slag gets in there and burns your resistance wires, also do small lite welds and cool with water so the actual sending unit don't get too hot between welds.

Anyway then you will have to shorten the float wire and bend it to match the oem. then crimp it onto the arm.

The sending unit wire will be shortened and stripped. use the new white plastic wire and bolt insulator with the square right up against the square dimpled area on the oem senders flange, the round rubber gastet will fit into the hole and keep it centered. Put nuts on farely tight and reinstall with the new rubber five hole gasket. it will stretch a bit to fit but will work fine.

So after only a few hours I have a perfectly working fuel gauge.