fuel gauge not accurate

[andersonj]

does the 412 fuel gauge also use a voltage stabilizer behind the cluster like the vanagons, my gauge always seems to show less fuel than whats in the tank and sometimes the needle bounces around. If I fill the tank it shows roughly 3/4.

any tips on troubleshooting, appreciated

[raygreenwood]

You know...I should know the answer to that...but I have had no actual troubles with the gauges themselves...mostly with the sending unit. I will look at one tonight and see.

For the moment....you should look at the sending unit tube itself....and look at Jim Adneys site. He rebuilds or refurbishes them.

Some availability information here. Some of the type 3 units are identical.
https://www.thesamba.com/vw/forum/viewtopic.php?t=656210&highlight=fuel+sending+unit

https://www.thesamba.com/vw/forum/viewtopic.php?t=616946&highlight=fuel+sending+unit

https://www.thesamba.com/vw/forum/viewtopic.php?t=443520&highlight=fuel+sending+unit

And ground quality is critical

https://www.thesamba.com/vw/forum/viewtopic.php?t=562659&highlight=fuel+sending+unit

Great information

http://home.clara.net/hallvw/fuelsend.htm

Also good info

https://www.thesamba.com/vw/forum/viewtopic.php?t=363430&highlight=fuel+sending+unit

https://www.thesamba.com/vw/forum/viewtopic.php?t=363430&highlight=fuel+sending+unit+rebuild

I think Ataraxia had a rebuild thread on these somewhere.

The type 4 fuel gauge sending unit is part # 411 919 049.

I have not measured. I think it may be slightly longer than the type 3 sending unit. Ray