1980s 1989 Cadillac Fleetwood FWD Fuel Sending unit replacement/ repair

[dennisspeaks]

I have been searching for a new fuel sending unit for my 89 Fleetwood (Front Wheel Drive) but as of yet have not been able to find one.  Any ideas where I can find one or a repair shop?  Mine works when it is half full.  Of course I would prefer to replace it instead of waiting for repair.  Sure wish they were easy to take out and replace like my 89 Town Car.

Thanks.

Dennis

[James Landi]

Dennis,

Perhaps it's mechanically stuck, hung up on some oxidation from a long standing, partially empty tank. It may come back to life over time as you drive the car. Does the fuel economy range digital readout work for you if you fill the tank?---   Using your "trip-o-meter" as a fall back could work for you, and perhaps with patience, a miracle will occur.  The service manager at my local Cadillac dealer often says that Cadillacs have "curative powers."  Happy day, James

[TJ Hopland]

Its the gauge that has issues?   Have you done any testing to verify that the issue is in the tank and not in the wiring or gauge?

Interesting that its a 2 year only item but looking at low long the hard lines are I bet that is what is unique about it.

[dennisspeaks]

Hi James, thanks for your reply.  I have no idea if it's hung up on oxidation, everything else works, it's been doing this for a few years, I am just at that point that it is bothering me enough to fix it.  I had thought about cleaning it up and putting a new float on it.  The company that could repair the one for my 89 Town Car was 3 months behind but don't repair these.  Fortunately for me I found one at a local pick and pull that was in great condition and works great.

Dennis,

Perhaps it's mechanically stuck, hung up on some oxidation from a long standing, partially empty tank. It may come back to life over time as you drive the car. Does the fuel economy range digital readout work for you if you fill the tank?---   Using your "trip-o-meter" as a fall back could work for you, and perhaps with patience, a miracle will occur.  The service manager at my local Cadillac dealer often says that Cadillacs have "curative powers."  Happy day, James

[dennisspeaks]

Hey TJ, I have not done any testing on the wiring, only the control module from another 89 Deville with no change.

Its the gauge that has issues?   Have you done any testing to verify that the issue is in the tank and not in the wiring or gauge?

Interesting that its a 2 year only item but looking at low long the hard lines are I bet that is what is unique about it.

[James Landi]

Dennis,

Among our several characteristics of "like-mindednesses" is our propensity to obsess about minor faults on our ancient and fully depreciated cars.  I drove an 83 Eldorado for 24 years, it clocked 317,000 miles and the interior was entirely worn out... I think I had 4 Maaco paint jobs, and Kristina and I replaced the vinyl top and I kept it washed and waxed .  I made myself focus on the outside of the car, and rarely looked around the torn up and aged out insides.  By the way, all of the electronics and automatic climate control and road leveler worked perfectly.  It's a matter of self discipline ... not letting a minor fault take on major proportions!!   Happy day, James

[dennisspeaks]

All a matter of perspective James,

Knowing where I am sitting gas wise for me is a big thing especially taking it to car shows out of town which I have yet to do plus my wife and daughter drive it occasionally.  It's not as bad as my Town Car was because it never showed if I was empty or full and not that that cars is working the Caddy needs to be working as well like clockwork just like the rest of the car. 

You sure put in some work on the Eldo, 4 Maaco paint jobs is a lot. I love me some Eldos as well.

Dennis,

Among our several characteristics of "like-mindednesses" is our propensity to obsess about minor faults on our ancient and fully depreciated cars.  I drove an 83 Eldorado for 24 years, it clocked 317,000 miles and the interior was entirely worn out... I think I had 4 Maaco paint jobs, and Kristina and I replaced the vinyl top and I kept it washed and waxed .  I made myself focus on the outside of the car, and rarely looked around the torn up and aged out insides.  By the way, all of the electronics and automatic climate control and road leveler worked perfectly.  It's a matter of self discipline ... not letting a minor fault take on major proportions!!   Happy day, James

[TJ Hopland]

It may be worth finding the connector back by the tank and unplugging it to see what the gauge does.  It should go to the max one direction.   Figure out which pin is the sender and ground it on the car side it should max the other direction.  If it does that likely means you are good from there to the gauge. 

On the tank side of things I can't remember if they are sharing the ground between the sender and pump. Even if they are there still could be a ground issue throwing off the reading.  I do recall on some models the ground path got tangled up with the level sensor module for the auto leveling.  I think the ground for the auto level ties into the tank ground before the actual ground so you could end up trying to ground through the sensor instead of actual ground. 

I have not seen my 90 manual for a while but was going to be out on the shop today so I will keep an eye out for it and see what it says for whats likely going on back there.

[dennisspeaks]

Thanks TJ, noted, I will add this info to my how to resource file.

It may be worth finding the connector back by the tank and unplugging it to see what the gauge does.  It should go to the max one direction.   Figure out which pin is the sender and ground it on the car side it should max the other direction.  If it does that likely means you are good from there to the gauge. 

On the tank side of things I can't remember if they are sharing the ground between the sender and pump. Even if they are there still could be a ground issue throwing off the reading.  I do recall on some models the ground path got tangled up with the level sensor module for the auto leveling.  I think the ground for the auto level ties into the tank ground before the actual ground so you could end up trying to ground through the sensor instead of actual ground. 

I have not seen my 90 manual for a while but was going to be out on the shop today so I will keep an eye out for it and see what it says for whats likely going on back there.