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Dann Tellez
Samba Member
Joined: September 03, 2013
Posts: 201
Location: Monterrey
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 Posted: Fri Jul 16, 2021 4:59 pm Post subject: Fuel sender pin? |
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Hello folks.
I have a problem with my fuel sender. It was installed a couple years ago in my fuel tank, however it was never used before until now that I have a new gas gauge. The problem is that it doesn’t read anything. I’m not really sure if the person who installed the sender removed the pin at the top of it. How can I know if this is my case. I’m guessing that since the pin holds the reader at the top the gauge should show a full tank read. I’m I correct?
Thank you! |
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busdaddy
Samba Member
Joined: February 12, 2004
Posts: 53221
Location: Surrey B.C. Canada, but thinking of Ukraine
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| Posted: Fri Jul 16, 2021 5:04 pm Post subject: Re: Fuel sender pin? |
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Pull the wire off the center terminal (surrounded in plastic) and ground it to the body or engine, the gauge should read full. If it doesn't there's more going on in there than just a forgotten shipping pin.
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Rust NEVER sleeps and stock never goes out of style.
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Слава Україні! |
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Dann Tellez
Samba Member
Joined: September 03, 2013
Posts: 201
Location: Monterrey
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| Posted: Fri Jul 16, 2021 5:15 pm Post subject: Re: Fuel sender pin? |
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| busdaddy wrote: |
| Pull the wire off the center terminal (surrounded in plastic) and ground it to the body or engine, the gauge should read full. If it doesn't there's more going on in there than just a forgotten shipping pin. |
Thanks, I already did that. And it reads full, the problem is when is connected to the terminal, tank is not full but at least has a quarter inside.I don’t know if there something with my gauge since it’s 6v. I’ve heard that sometimes the read is not correct due this. |
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busdaddy
Samba Member
Joined: February 12, 2004
Posts: 53221
Location: Surrey B.C. Canada, but thinking of Ukraine
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| Posted: Fri Jul 16, 2021 5:47 pm Post subject: Re: Fuel sender pin? |
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Where did you buy the sender, most new ones are DOA lately, especially the "plain white box" Chinese ones. Is the short ground wire connected between a hold down screw and the body?
_________________
Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
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BarryL 
Samba Member
Joined: November 01, 2004
Posts: 15489
Location: Casa de Oro, California
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| Posted: Fri Jul 16, 2021 6:42 pm Post subject: Re: Fuel sender pin? |
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| One way to tell if the pin is NOT installed is to rock the bus and watch the gauge move. |
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BonTonRoulet
Samba Member
Joined: September 29, 2020
Posts: 486
Location: Mississippi
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| Posted: Fri Jul 16, 2021 6:46 pm Post subject: Re: Fuel sender pin? |
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I'm no electrical engineer and I didn't stay in a Holiday Inn Express last night, that being said, if the way to check one of these fuel gauge senders is to measure the resistance in different positions of the float with an ohm meter, why couldn't those measurements be made at the wiring at the gauge? In other words, measure the resistance now, then add a few gallons of gas to the tank and take another measurement. If they are the same then you know it's not likely the gauge as the culprit.
Lucky for me, my neighbor is a retired electrical engineer. So prior to installing a new fuel gauge sender in my 66, I got up under the rear of the bus and hooked the wiring to the sender including the short wire to ground, had my neighbor turn on the ignition (I had yet to fit a fuel tank so no worries there!) and then as I held the sender horizontally I would ask him what the gauge was reading. Then I'd tilt it slightly less than horizontal and give it a gentle shake and ask again what he was seeing. "about 1/4 tank"...shake it a bit more "empty".....tilt it the other way "3/4 tank" and finally "full" so I knew before installing it that things were working like they should. |
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BonTonRoulet
Samba Member
Joined: September 29, 2020
Posts: 486
Location: Mississippi
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| Posted: Fri Jul 16, 2021 6:57 pm Post subject: Re: Fuel sender pin? |
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| BarryL wrote: |
| One way to tell if the pin is NOT installed is to rock the bus and watch the gauge move. |
With the key in the "on" position of course. I like that method. Perhaps the most simple and non elegant test!  |
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Bruce Amacker
Samba Member
Joined: December 26, 2007
Posts: 1796
Location: Cleveland, Ohio
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| Posted: Sat Jul 17, 2021 7:39 am Post subject: Re: Fuel sender pin? |
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The resistance range of the sender is about (0-5) ohms full to about 80 ohms empty. If you have an access hole, remove the wire and test the resistance of the sender to ground using a digital voltmeter, even the cheapie HF works fine here. If you don't have an access hole and long arms you may be able to reach around the engine and do the same thing. If the pin is still in place it will read 0-5 no matter what the fuel level is.
PS the last sender I put in a new aftermarket tank, the pin actually prevented the sender from being installed because the size of the hole was so tight. My gut feeling is that your problem is not a pin being present.
_________________
'66 Deluxe Bus
'65 Standard Bus
Build threads:
'66- http://www.leakoil.net/forum/viewtopic.php?f=23&t=2888&sid=54d8dedfb3822f99c7f2ea430cb4e856
'65- http://leakoil.net/forum/viewtopic.php?f=23&t=4263 |
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Dann Tellez
Samba Member
Joined: September 03, 2013
Posts: 201
Location: Monterrey
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| Posted: Sat Jul 17, 2021 10:06 am Post subject: Re: Fuel sender pin? |
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| Bruce Amacker wrote: |
The resistance range of the sender is about (0-5) ohms full to about 80 ohms empty. If you have an access hole, remove the wire and test the resistance of the sender to ground using a digital voltmeter, even the cheapie HF works fine here. If you don't have an access hole and long arms you may be able to reach around the engine and do the same thing. If the pin is still in place it will read 0-5 no matter what the fuel level is.
PS the last sender I put in a new aftermarket tank, the pin actually prevented the sender from being installed because the size of the hole was so tight. My gut feeling is that your problem is not a pin being present. |
Thanks, I made a test and the resistance of the sender is 100 ohms. Is time to change the sender? I bought it a couple years ago. Is VDO |
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telford dorr
Samba Member
Joined: March 11, 2009
Posts: 3631
Location: San Diego (Encinitas)
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| Posted: Sat Jul 17, 2021 10:17 am Post subject: Re: Fuel sender pin? |
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| Dann Tellez wrote: |
| And it reads full, the problem is when is connected to the terminal, tank is not full but at least has a quarter inside.I don’t know if there something with my gauge since it’s 6v. I’ve heard that sometimes the read is not correct due this. |
Are you implying that you're running a 6 volt gas gauge on 12 volts?
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'71 panel, now with FI
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When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
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Dann Tellez
Samba Member
Joined: September 03, 2013
Posts: 201
Location: Monterrey
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| Posted: Sat Jul 17, 2021 11:32 am Post subject: Re: Fuel sender pin? |
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| telford dorr wrote: |
| Dann Tellez wrote: |
| And it reads full, the problem is when is connected to the terminal, tank is not full but at least has a quarter inside.I don’t know if there something with my gauge since it’s 6v. I’ve heard that sometimes the read is not correct due this. |
Are you implying that you're running a 6 volt gas gauge on 12 volts? |
Correct, I’m using a 6v gauge on 12 Volts. I’ve read that many people is using it like that and sometimes the read is not correct. But better than nothing. |
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Bruce Amacker
Samba Member
Joined: December 26, 2007
Posts: 1796
Location: Cleveland, Ohio
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| Posted: Sat Jul 17, 2021 2:46 pm Post subject: Re: Fuel sender pin? |
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| Dann Tellez wrote: |
Thanks, I made a test and the resistance of the sender is 100 ohms. Is time to change the sender? I bought it a couple years ago. Is VDO |
Where is the fuel in the tank? If it's stone empty 100 ohms is on the high side but could be OK. Put some fuel in it and see if it comes down in resistance. If it has fuel in it, the sender is bad. I've had better luck with VDO that the Chinese senders but it could still be bad.
Running a 6v gauge on 12v is OK but makes it less accurate. If you want it to be more accurate put a 162 ohm resistor inline in the power feed, it will drop the voltage in half. "Accurate" is a very misleading term, if it's within a quarter tank of reality you're doing well.
_________________
'66 Deluxe Bus
'65 Standard Bus
Build threads:
'66- http://www.leakoil.net/forum/viewtopic.php?f=23&t=2888&sid=54d8dedfb3822f99c7f2ea430cb4e856
'65- http://leakoil.net/forum/viewtopic.php?f=23&t=4263 |
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