Forklift Posted October 16, 2023 Report Share Posted October 16, 2023 (edited) Mods: I tried to post this in the Fuel/ECU sub-forum but I don't have 10 posts yet; feel free to move this over Hi everyone, been a long time lurker, first time poster. I picked up a 87 Conquest two weeks ago and have been having fun going through it. It sat for 15ish years, mostly inside however when I pulled the gas tank, it needed cleaning; when I removed the sending unit, the sensor (is it a sensor? It looks like it's a housing for a resistor) was disintegrated. These sending units are no longer available, neither OEM nor aftermarket. I called around a couple places and was getting an estimated 6 months and $350-$600 to rebuild it; Tristar Radiator which was recommended here and elsewhere was so backed up they wouldn't even give a price because they aren't taking new work. In posting on the facebook group, someone mentioned other folks had success with a Montero sending unit, specifically part number MB571603. This part IS available from Mitsubishi for ~$100 based on where you order it from, it is also available aftermarket, for ~$20. I believed my issue was the disintegrated sensor, so I took a $20 gamble on amazon and bought this one aftermarket one hopeing I could just take the sensor off of it and put in on my old sender: https://www.amazon.com/dp/B09VB8CG84 . The short story is that it worked. Looking at the pictures for this sending unit, it appears that while that hat is different, and the connector is different, the rest of it is very very very mechanically close to ours with the stuff that goes in the tank. In theory if you felt like doing some fabrication to your existing sender hat, you may be able to figure out how to disconnect (or cut out) your existing mechanism and attach the one from the new sender. I didn't feel like going this route because my suspicion is that the only thing wrong with mine was the sender and I'm comfortable soldering a single wire. I'd imagine that say if your float was bad on your original sender, you'd likely have success replacing yours with the one from this Montero sender. As stated above, soldering in the new sensor worked. The only weird thing is that while the guage moves as you would expect by manually moving the float arm, my low fuel warning lite seems to stay on all the time when the ignition is on ON; this may be a function that the car isn't actually running, and/or that it has no fuel tank and the fuel pump isn't connected; I'm not sure, as this is the first experience I have with one of these cars. Even if it's abnormal, I'll take a working needle with an always on low fuel light over nothing! Pic 1 and 2: Side by Side, you can see the Montero (bottom) sender looks pretty darn similar with regards to everything that lives in the tank. Pic 3: You can see the hats are different; the Montero sender has 3 holes and is more triangular in shape. The holes in the Montero hat in no way match up to to our hat. Pic 4: Connectors are different however both are three terminal setup Pic 5: My dirty sender; all I needed to do is take a soldering iron, melt the old solder, remove the old wire Pic 6: Here's the connection point on my original sender, after I removed the old sensor wire I took a file and filed mine down some to get rid of rust/dirt Pic 7: On the Montero sender, I just cut the wire and stripped a little of the insulation off, and then soldered it onto my old sender. I had soaked my sender (not fully submerged, just up to the bottom of the hat) and soaked/submerged pickup in vinegar for 24hrs in between Pic 6 and 7, it worked great! Pic 8: Attach the sender sensor on the bottom of the rod Pic 9: Here's the cleaned up original sender with the new Montero sensor Pic 10: Here's my working gas gauge when manipulating the float arm! Edited October 16, 2023 by Forklift 1 1 Link to comment Share on other sites More sharing options...
kev Posted October 24, 2023 Report Share Posted October 24, 2023 Thank you for posting this! It is very informative. Let us know if you have luck figuring out why the light is staying on (probably will have to make a new thread due to restrictions in the FAQ forum but we can merge it into this one later on). But regardless, this is great news for the community on a replacement of an obsolete part. Link to comment Share on other sites More sharing options...
Recommended Posts