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photoghog Samba Member
Joined: January 31, 2009 Posts: 105 Location: Bella Vista Arkansas
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Posted: Fri Jun 17, 2022 9:33 am Post subject: gas gauge issues |
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Hi all,
77 westy.
I've routinely had issues with my gas gauge where it would read accurately then go to empty. When this would happen, I would reach around the back of the cluster and wiggle the wires and then it would read correctly again (I know, I know...not very scientific). The last time I did this, the gas gauge went WAY past Full and get stuck there. It's been that way every since. Turn on the ignition, gauge reads way past full (the needle actually disappears). The sender appeared to be working appropriately because I was getting accurate readings. I read several threads where folks said the gauge itself can be faulty and then I've seen mention of a vibrator (that's what she said). Based on the symptoms of what I described, would you start with a replacement gas guage? _________________ 1977 westy "Gus", subie swapped with ej22
Insta @get_on_the_gus_bus |
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busdaddy Samba Member
Joined: February 12, 2004 Posts: 51057 Location: Surrey B.C. Canada, but thinking of Ukraine
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Posted: Fri Jun 17, 2022 10:04 am Post subject: Re: gas gauge issues |
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Start with a mirror or camera and see if all your wiggling broke the insulator around where the brown wire (G terminal) enters the back of the cluster. _________________ 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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cmonSTART Samba Member
Joined: July 15, 2014 Posts: 1915 Location: NH
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Posted: Fri Jun 17, 2022 10:07 am Post subject: Re: gas gauge issues |
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There is an insulating board on the back that the nuts and wire terminals press up against when you tighten them - I think it's paper or something and likely it has worn through.
I replaced mine recently with a piece of plastic from a milk jug - 1000% better. _________________ '78 Bus 2.0FI
de K1IGS |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Fri Jun 17, 2022 10:09 am Post subject: Re: gas gauge issues |
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I had a similar issue and it was a bad crimp from the factory. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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photoghog Samba Member
Joined: January 31, 2009 Posts: 105 Location: Bella Vista Arkansas
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Posted: Fri Jun 17, 2022 10:56 am Post subject: Re: gas gauge issues |
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Interesting. You don't happen to have a pic of the insulating board, do you?
cmonSTART wrote: |
There is an insulating board on the back that the nuts and wire terminals press up against when you tighten them - I think it's paper or something and likely it has worn through.
I replaced mine recently with a piece of plastic from a milk jug - 1000% better. |
_________________ 1977 westy "Gus", subie swapped with ej22
Insta @get_on_the_gus_bus |
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cmonSTART Samba Member
Joined: July 15, 2014 Posts: 1915 Location: NH
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photoghog Samba Member
Joined: January 31, 2009 Posts: 105 Location: Bella Vista Arkansas
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Posted: Fri Jun 17, 2022 11:35 am Post subject: Re: gas gauge issues |
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Got it. Thanks for sharing.
_________________ 1977 westy "Gus", subie swapped with ej22
Insta @get_on_the_gus_bus |
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photoghog Samba Member
Joined: January 31, 2009 Posts: 105 Location: Bella Vista Arkansas
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Posted: Sat Jun 18, 2022 11:51 am Post subject: Re: gas gauge issues |
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I replaced the insulator and am still have the same issue. With the key on, the gas gauge goes all the way past full. I know I don't have a full tank.
Anyone else experienced this and have other suggestions? _________________ 1977 westy "Gus", subie swapped with ej22
Insta @get_on_the_gus_bus |
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mikedjames Samba Member
Joined: July 02, 2012 Posts: 2714 Location: Hamble, Hampshire, UK
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Posted: Sat Jun 18, 2022 1:43 pm Post subject: Re: gas gauge issues |
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If it uses a Zener diode type stabiliser (voltage regulator) for the fuel gauge (more modern): if you accidentally short 12 volts to the output side of the stabiliser, it will blow the internal diode, which will then go open circuit, leaving the output stuck at 12 volts.
Also if the voltage regulator loses its earth, coming loose, it will produce 12 volts.
Check the voltage on the output of the regulator is either about a constant 5 volts, or pulsing on and off 12 volts, averaging 5 volts (older bimetallic strip style) _________________ Ancient vehicles and vessels
1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.
1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy |
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photoghog Samba Member
Joined: January 31, 2009 Posts: 105 Location: Bella Vista Arkansas
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Posted: Tue Jun 21, 2022 5:07 pm Post subject: Re: gas gauge issues |
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mikedjames wrote: |
If it uses a Zener diode type stabiliser (voltage regulator) for the fuel gauge (more modern): if you accidentally short 12 volts to the output side of the stabiliser, it will blow the internal diode, which will then go open circuit, leaving the output stuck at 12 volts.
Also if the voltage regulator loses its earth, coming loose, it will produce 12 volts.
Check the voltage on the output of the regulator is either about a constant 5 volts, or pulsing on and off 12 volts, averaging 5 volts (older bimetallic strip style) |
I bet that's want happened. When I pulled the dash plate out, the 12v wire was loose and shorted on the metal plate and blew the fuse. Replace the gauge I'm guessing? _________________ 1977 westy "Gus", subie swapped with ej22
Insta @get_on_the_gus_bus |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Tue Jun 21, 2022 5:15 pm Post subject: Re: gas gauge issues |
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no - the regulator. Do you have a stereo in the bus? If so it will be a zener diode unit. If not it will be a heated bimetallic unit. The difference is that the heated one will cause clicks in the radio as it cycles.
113957099A
example https://www.amazon.com/Dade-113957099A-Vibrator-Speedometer-Beetle/dp/B01H1BVNQA
_________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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photoghog Samba Member
Joined: January 31, 2009 Posts: 105 Location: Bella Vista Arkansas
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Posted: Tue Jun 21, 2022 5:38 pm Post subject: Re: gas gauge issues |
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mikedjames wrote: |
If it uses a Zener diode type stabiliser (voltage regulator) for the fuel gauge (more modern): if you accidentally short 12 volts to the output side of the stabiliser, it will blow the internal diode, which will then go open circuit, leaving the output stuck at 12 volts.
Also if the voltage regulator loses its earth, coming loose, it will produce 12 volts.
Check the voltage on the output of the regulator is either about a constant 5 volts, or pulsing on and off 12 volts, averaging 5 volts (older bimetallic strip style) |
I bet that's want happened. When I pulled the dash plate out, the 12v wire was loose and shorted on the metal plate and blew the fuse. Replace the gauge I'm guessing? _________________ 1977 westy "Gus", subie swapped with ej22
Insta @get_on_the_gus_bus |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Tue Jun 21, 2022 5:55 pm Post subject: Re: gas gauge issues |
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why did you double post half an hour later when the answer was given to you along with a photo out of a 77 bus for your wiring reference. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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photoghog Samba Member
Joined: January 31, 2009 Posts: 105 Location: Bella Vista Arkansas
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Posted: Tue Jun 21, 2022 7:00 pm Post subject: Re: gas gauge issues |
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SGKent wrote: |
why did you double post half an hour later when the answer was given to you along with a photo out of a 77 bus for your wiring reference. |
Perhaps it was accidental. I hit submit and closed my computer. When I opened my computer after dinner, it was at the submit screen so I assumed it didn't go through so I resubmitted the form. Apologies for the inconvenience _________________ 1977 westy "Gus", subie swapped with ej22
Insta @get_on_the_gus_bus |
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photoghog Samba Member
Joined: January 31, 2009 Posts: 105 Location: Bella Vista Arkansas
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Posted: Tue Jun 21, 2022 7:01 pm Post subject: Re: gas gauge issues |
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There is a stereo in the bus. My setup is identical to this pic. Thanks for taking the time to send it _________________ 1977 westy "Gus", subie swapped with ej22
Insta @get_on_the_gus_bus |
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photoghog Samba Member
Joined: January 31, 2009 Posts: 105 Location: Bella Vista Arkansas
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Posted: Fri Jun 24, 2022 3:41 pm Post subject: Re: gas gauge issues |
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Thanks for the suggestion and link. I now have a fully operational gas gauge again _________________ 1977 westy "Gus", subie swapped with ej22
Insta @get_on_the_gus_bus |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Fri Jun 24, 2022 3:45 pm Post subject: Re: gas gauge issues |
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kudos for hanging in there and glad it works. I had lots of trouble with my 1977 gauge and it was a bad factory wire connector crimp. I just happened to hit the wire with my hand one day when working on it and the gauge dropped then came back up a few seconds later. Touched the wire again and it did it again. Replaced the crimp and it has been rock solid since. We originally though it was a defective zener causing voltage fluctuations, but it was the crimp. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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photoghog Samba Member
Joined: January 31, 2009 Posts: 105 Location: Bella Vista Arkansas
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Posted: Sat Jun 25, 2022 7:53 pm Post subject: Re: gas gauge issues |
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SGKent wrote: |
kudos for hanging in there and glad it works. I had lots of trouble with my 1977 gauge and it was a bad factory wire connector crimp. I just happened to hit the wire with my hand one day when working on it and the gauge dropped then came back up a few seconds later. Touched the wire again and it did it again. Replaced the crimp and it has been rock solid since. We originally though it was a defective zener causing voltage fluctuations, but it was the crimp. |
You don't know how excited I am to not to have to guess how much fuel I have. _________________ 1977 westy "Gus", subie swapped with ej22
Insta @get_on_the_gus_bus |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Sat Jun 25, 2022 8:26 pm Post subject: Re: gas gauge issues |
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just be aware that bus gauges can be fine one day and goofy on a trip a day later. ALWAYS keep an eye on how many miles it has been from the last fill up. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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