I'm going to try rebuilding mine on a 1975 firebird, thanks for taking the time to post this. I rebuild parts all the time, it's cool to do and saves money. Back in the day you could buy starter rebuild kits, I lucked out and found one at NAPA, for my high torque GM starter. 10 bucks vs 100 bucks. 👍👍🏁🏁
You are welcome. Here is a tip. Forget the big auto parts stores and find a starter/alternator professional rebuild shop for the parts, it's what the pros do!
Nice video, but what you think is full and empty is backwards. Low resistance is full, high resistance is empty. Think about it, the pickup tube sits at the bottom of the tank. When the float is close to that, it is empty.
Thank you so much for sharing your valuable skill. I am going to take on the challenge to rebuild my fuel sending unit on my 1962 AMC Rambler American.
Excellent video. I had my unit out once already but did not touch up the contact tip on the arm with solder and my problem continued. I will remove and apply a dab of solder to the contact tip and hope that fixes the problem. I also did not check the ohm resistance on the bench with an ohm meter before installing the unit, which is the smart way to proceed. Right now my meter on the dash shows empty when the tank is full of fuel so the contact arm must not be making contact with the resistor wire in the full up position. Perhaps the arm also needs to be tweaked some so it contacts the resistor wire at that point. Thanks again.
Sorry for your correction high resistant at 70 ohms means empty and 10 ohms means full tank. Voltage increases to the gauge with less resistance . good demo cheers
I have an 1987 XJS that has a similiar sender. It connects with 3 wires though and has two arms with contact nipples on the inside of the sending unit that wipes against walls (once with wires the other, shorter, against a flat wall). I've cleaned all the contacts and tried my best to get good contact on both but it will only raise the gauge to half a tank when I test it. The contact arms have been severely bent so I'm trying to do my best to re-bend them but obviously it will never be picture perfect. Can I diagnose the problem to the sending unit 100% and get a replacement while confirming the wiring's good?
the best fuel sending unit is a reed switch fool proof very accurate USA standard 33 ohms full 244 ohms empty come with a good rubber 5 hole gasket has 2 push on connectorsrun 2 wires from sender to gauge on dash will work with american gauges order on line just measure depth of fuel tank minus 1/2 in
Okay you have this completely wrong. The gauge should read full at 10 ohms. You are telling people that high resistance equals a full tank. That is back wards. I rebuild these professionally and pretty much everything you are doing is making this worse.
@@HowToHeaven the problem with the senders is that they build series resistance over time. Recall how you saw .3 ohms when it should have read 0.00? The connections all need to be cleaned up and then soldered until you get to 0.00. This means both ends of the ribbon cable and even inside the resistor box where the resistance wire attaches. This is not an easy soldering job. But as much as anything else you missed the biggest problem of all. The float arm axle has to ground to the resistor case. The purpose of the spring is to put pressure on the axle pushing it laterally into the inside of the case. If you look at the video you will see the rust spot. The flange that contacts this must also be cleaned. Solder is too soft to do what you are asking it to do. As the wire wound coil abrades it, it collects between the turns of the wire shorting them out. The sweep arm contact needs to be dressed with a jewelers file to remove any sharp corners and flat spots. In extreme cases a new brass contact shaped like half a sphere is soldered on to the end of the sweep arm. It is also very important to keep the angle of the sweep arm contact correct so it doesn't dig into the wire wound resistor. Bending it down tends to cause it to do this. The resistor wire needs to be wet sanded only in the direction of the wire using emery paper and contact cleaner. That is how you get the dead spots to clear up. Never use an eraser. It will shift the position of the wires if you go across the grain and that will pretty well ruin the sender. Occasionally I get senders from people that they have tried to fix and inadvertently ruined. They get unhappy when they discover these self inflicted fatalities. desertclassicparts.com/product/standard-fuel-sending-unit-rebuilding-service-send-us-your-core/
@@williambasore810 Thanks for this detailed write up William, I couldn't find this info anywhere else on the internet, how to PROPERLY restore the rare and hard to find fuel sending unit in my car. Had a strong feeling soldering the tip of wiper was not what fixed this gentleman's fuel sending unit in the video. It was likely cleaning the resistor wire that fixed his issue.
@@Joseph-C I have put a more extensive explanation of the rebuilding process here: desertclassicparts.com/fuel-sending-unit-rebuilding-service/#more-1172
my sending unit read 91 ohms in any position, so I pulled mine apart and it was full of rust!
Thanks for posting!
I'm going to try rebuilding mine on a 1975 firebird, thanks for taking the time to post this. I rebuild parts all the time, it's cool to do and saves money. Back in the day you could buy starter rebuild kits, I lucked out and found one at NAPA, for my high torque GM starter. 10 bucks vs 100 bucks. 👍👍🏁🏁
You are welcome. Here is a tip. Forget the big auto parts stores and find a starter/alternator professional rebuild shop for the parts, it's what the pros do!
Nice video, but what you think is full and empty is backwards. Low resistance is full, high resistance is empty. Think about it, the pickup tube sits at the bottom of the tank. When the float is close to that, it is empty.
Thanks for the reply.
Thank you so much for sharing your valuable skill. I am going to take on the challenge to rebuild my fuel sending unit on my 1962 AMC Rambler American.
You are welcome!
"Max up" position is the other way from what you're showing in the video. The full position is when float is farthest from pickup sock.
Exactly the video I needed to watch. Many thanks - I hope a Morris 8 (1946) will benefit from the principles you have described!
My fuel gauge now works. Thanks very much my friend.
Your welcome, thank for watching!
This is an EXCELLENT video. Exact info I was looking for. THX!
Good information, tab slightly bending was nice to know not to bend them all the way over.
Excellent video. I had my unit out once already but did not touch up the contact tip on the arm with solder and my problem continued. I will remove and apply a dab of solder to the contact tip and hope that fixes the problem. I also did not check the ohm resistance on the bench with an ohm meter before installing the unit, which is the smart way to proceed. Right now my meter on the dash shows empty when the tank is full of fuel so the contact arm must not be making contact with the resistor wire in the full up position. Perhaps the arm also needs to be tweaked some so it contacts the resistor wire at that point. Thanks again.
Sorry for your correction high resistant at 70 ohms means empty and 10 ohms means full tank. Voltage increases to the gauge with less resistance . good demo cheers
Thanks for the additional info!
I have an 1987 XJS that has a similiar sender. It connects with 3 wires though and has two arms with contact nipples on the inside of the sending unit that wipes against walls (once with wires the other, shorter, against a flat wall). I've cleaned all the contacts and tried my best to get good contact on both but it will only raise the gauge to half a tank when I test it.
The contact arms have been severely bent so I'm trying to do my best to re-bend them but obviously it will never be picture perfect.
Can I diagnose the problem to the sending unit 100% and get a replacement while confirming the wiring's good?
Been worken on mine for 25 years, still can't find the problem, lol
Lol try your purge valve 😂
You should check again.
Soldering a piece of copper onto the copper end would be more durable than solder.
the best fuel sending unit is a reed switch fool proof very accurate USA standard 33 ohms full 244 ohms empty come with a good rubber 5 hole gasket has 2 push on connectorsrun 2 wires from sender to gauge on dash will work with american gauges order on line just measure depth of fuel tank minus 1/2 in
Great information! Thanks for watching!
Okay you have this completely wrong. The gauge should read full at 10 ohms. You are telling people that high resistance equals a full tank. That is back wards. I rebuild these professionally and pretty much everything you are doing is making this worse.
Thanks, why don't you leave your contact info so people can send their sender units to you? BTW I fixed mine using the methods I showed on this video.
@@HowToHeaven the problem with the senders is that they build series resistance over time. Recall how you saw .3 ohms when it should have read 0.00? The connections all need to be cleaned up and then soldered until you get to 0.00. This means both ends of the ribbon cable and even inside the resistor box where the resistance wire attaches. This is not an easy soldering job. But as much as anything else you missed the biggest problem of all. The float arm axle has to ground to the resistor case. The purpose of the spring is to put pressure on the axle pushing it laterally into the inside of the case. If you look at the video you will see the rust spot. The flange that contacts this must also be cleaned. Solder is too soft to do what you are asking it to do. As the wire wound coil abrades it, it collects between the turns of the wire shorting them out. The sweep arm contact needs to be dressed with a jewelers file to remove any sharp corners and flat spots. In extreme cases a new brass contact shaped like half a sphere is soldered on to the end of the sweep arm. It is also very important to keep the angle of the sweep arm contact correct so it doesn't dig into the wire wound resistor. Bending it down tends to cause it to do this. The resistor wire needs to be wet sanded only in the direction of the wire using emery paper and contact cleaner. That is how you get the dead spots to clear up. Never use an eraser. It will shift the position of the wires if you go across the grain and that will pretty well ruin the sender. Occasionally I get senders from people that they have tried to fix and inadvertently ruined. They get unhappy when they discover these self inflicted fatalities. desertclassicparts.com/product/standard-fuel-sending-unit-rebuilding-service-send-us-your-core/
@@williambasore810 Thanks for this detailed write up William, I couldn't find this info anywhere else on the internet, how to PROPERLY restore the rare and hard to find fuel sending unit in my car. Had a strong feeling soldering the tip of wiper was not what fixed this gentleman's fuel sending unit in the video. It was likely cleaning the resistor wire that fixed his issue.
@@Joseph-C I have put a more extensive explanation of the rebuilding process here: desertclassicparts.com/fuel-sending-unit-rebuilding-service/#more-1172