HOW TO HOOK UP AN AFTERMARKET FUEL LEVEL GAUGE

[smokin90]

IM TRYING TO HOOK UP AN AFTERMARKET FUEL LEVEL GAUGE ON A 1989 F-350 7.3L IDI AND IT HAS TWO TANKS

 

[icanfixall]

I understand the question asked but I don't know what sender you have or exactly what you need to know. Front tank or rear tank... It makes a big differance in which one you do. The front tank can stay in the truck but the rear tank requires to be dropped. Its nearly impossible to get a near full rear tank down safely. If the senders have the suction broken off they will only draw down to about the 1/4 tank level and stop there. Then you need a suction hose down the fill pipe to suck out whats left.

 

[smokin90]

so theres no way to hook both tanks to one gauge? but i have to drop both tanks, theres no way too splice into a wire coming from the tanks ?

 

[w4dsb]

you can feed both level sensors to a switch and be able to use 1 gauge for both tanks

 

[bike-maker]

This is how the factory gauge is wired. ^^^^^
The fuel selector valve not only switches where the fuel is coming from, it also dictates which fuel sender is sending it's signal to the gauge. So there's only 2 wires going from the FSV to the gauge, but 4 coming into the FSV.. from the 2 senders.
I'm in the process of constructing my own dash setup with custom gauges, and have already ordered 2 separate fuel level gauges. The tanks and sending units in my truck came out of a 89, which use a different ohm rating than the 84 dash, making my fuel gauge work backwards.
The fuel level gauges I ordered are a VDO part # 301216. Auto Meter also makes one with the same ohm range. They don't fit into one of the 3 standard ohm ranges of aftermarket gauges.

 

[smokin90]

you can feed both level sensors to a switch and be able to use 1 gauge for both tanks

the switch wont work thats already there to switch back and fourth between the tanks theres no wire there i can use

 

[smokin90]

This is how the factory gauge is wired. ^^^^^
The fuel selector valve not only switches where the fuel is coming from, it also dictates which fuel sender is sending it's signal to the gauge. So there's only 2 wires going from the FSV to the gauge, but 4 coming into the FSV.. from the 2 senders.
I'm in the process of constructing my own dash setup with custom gauges, and have already ordered 2 separate fuel level gauges. The tanks and sending units in my truck came out of a 89, which use a different ohm rating than the 84 dash, making my fuel gauge work backwards.
The fuel level gauges I ordered are a VDO part # 301216. Auto Meter also makes one with the same ohm range. They don't fit into one of the 3 standard ohm ranges of aftermarket gauges.

ok thanks for the help

 

[icanfixall]

Well it sounds like someone cut off the sending unit wires behind the dash. All year ford trucks that have two tanks will switch thru the tank supply and return switch under the truck. The dash will have a switch usually a rocker type that tells you front or rear when your using... Someone with a wireing skmatic can post a picture of the wires.

 

[smokin90]

Well it sounds like someone cut off the sending unit wires behind the dash. All year ford trucks that have two tanks will switch thru the tank supply and return switch under the truck. The dash will have a switch usually a rocker type that tells you front or rear when your using... Someone with a wireing skmatic can post a picture of the wires.

thats the switch im talking about isnt there anyway to go though it

 

[MIDNIGHT RIDER]

I am gonna make a stab at maybe answering your question, but you are a bit vague on just what you are trying to do.

You said "aftermarket fuel gauge"; by this are you meaning only the in-cab gauge itself and then trying to get it to work with the factory senders that are in the tanks ??

Or, did you also replace BOTH senders ??


To get ONE gauge to read between TWO tank-senders, you will have to use a SPDT toggle-switch to switch from one tank to the other.

The gauge wire connects to the center terminal and one sender wire to the top terminal and the other on the bottom.


If you did not replace both senders, are you certain that the aftermarket gauge is compatible with the factory senders ??


I need more information to give you a good answer.

 

[MIDNIGHT RIDER]

Does the factory electric tank-switching valve still exist on the truck in question ??

The switch in the dash did not switch gauge-senders; like already noted, the dash switch controlled the electric valve and the switching of the gauges was performed inside the valve.

Most of these trucks have had the electric valve dis-carded and some other means of switching tanks implemented.

 

[smokin90]

I am gonna make a stab at maybe answering your question, but you are a bit vague on just what you are trying to do.

You said "aftermarket fuel gauge"; by this are you meaning only the in-cab gauge itself and then trying to get it to work with the factory senders that are in the tanks ??

Or, did you also replace BOTH senders ??


To get ONE gauge to read between TWO tank-senders, you will have to use a SPDT toggle-switch to switch from one tank to the other.

The gauge wire connects to the center terminal and one sender wire to the top terminal and the other on the bottom.


If you did not replace both senders, are you certain that the aftermarket gauge is compatible with the factory senders ??


I need more information to give you a good answer.

im just putting in an aftermarket gauge the senders have never been changed as far as i know and the guy im putting it in for threw the box away so i dont know if the gauge is the right OHMs rateing

 

[smokin90]

Does the factory electric tank-switching valve still exist on the truck in question ??

The switch in the dash did not switch gauge-senders; like already noted, the dash switch controlled the electric valve and the switching of the gauges was performed inside the valve.

Most of these trucks have had the electric valve dis-carded and some other means of switching tanks implemented.

yes all of that is still in the truck

 

[MIDNIGHT RIDER]

My bet is that first, the old factory senders in the tanks are shot -- most of them have been dead for years; second, the gauge unit you have is not gonna be compatible with the senders, and third, you would be best to completely replace the senders AND gauge unit with two complete after-market tank-gauge sets, replacing the senders in the tanks and either using both gauges or wiring like I already explained and using one.

The senders will require some retrofitting to mate them onto the factory bulk-heads; better is to ignore the factory bulk-head and hole-saw a new hole for the sender to mount as intended.

I prefer SUNPRO gauge sets, as I have had good success with them on many applications.

Don't waste your money on more factory-issue senders; they were junk when these trucks were new.

Are you certain that the gauge is the problem and not the tank-senders ??

 

[smokin90]

My bet is that first, the old factory senders in the tanks are shot -- most of them have been dead for years; second, the gauge unit you have is not gonna be compatible with the senders, and third, you would be best to completely replace the senders AND gauge unit with two complete after-market tank-gauge sets, replacing the senders in the tanks and either using both gauges or wiring like I already explained and using one.

The senders will require some retrofitting to mate them onto the factory bulk-heads; better is to ignore the factory bulk-head and hole-saw a new hole for the sender to mount as intended.

I prefer SUNPRO gauge sets, as I have had good success with them on many applications.

Don't waste your money on more factory-issue senders; they were junk when these trucks were new.

Are you certain that the gauge is the problem and not the tank-senders ??

im not sure on that i will have to check that out and thanks alot for the help