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Sat Sep 20, 2014 10:07 am

I have a 72 campmobile in process of restoration. I wanted to test the fuel gage before I put the gas tank back in. I hook up the gage, sending unit and battery according to Bentley. As soon as I complete the circuit, the gage slams to full. I tested with another gage with the same results. I bought a new sending unit with the same results.

Any Ideas???

Sat Sep 20, 2014 10:20 am

Are you connecting the brown wire from the harness to the terminal with the plastic surrounding it on the sender? If yes then you'll have to find where you pinched that wire and it's grounding.

Sat Sep 20, 2014 11:00 am

I have it hooked up just like in Bentley. Battery to + on the gage. G on the gage to top of sending unit and battery ground to flange on sending unit. Is the 72 supposed to have a vibrator that is not shown??

Thanks,

Sat Sep 20, 2014 11:26 am

foster3704 wrote: Is the 72 supposed to have a vibrator that is not shown??
Not if it's really a 72, vibrators are for the float and arm style senders, not used on the tubular type.

Sat Sep 20, 2014 11:54 am

I'm beginning to think that the sending unit I paid high dollar for is bad. The resistance varies but is very low. With 109 ohms across the meter, I would expect high resistance somewhere to drop the voltage.

An aftermarket gage and sending unit is looking better all the time.

thanks,

Thu Sep 25, 2014 11:34 am

Does anyone know the typical full and empty resistance values of sending unit for the 72 type 2? I hooked a test rig similar to using a VW1301 and found that I needed about 4Kohm for an empty reading on the gage and about 400 ohms for full. Is this correct or am I trying to P up a rope?

Thanks,

Thu Sep 25, 2014 12:23 pm

Read through some of these, the OHM's were posted somewhere:

http://www.thesamba.com/vw/forum/viewtopic.php?t=380693&highlight=sender
http://www.thesamba.com/vw/forum/viewtopic.php?t=564551&highlight=sender
http://www.thesamba.com/vw/forum/viewtopic.php?t=557778&highlight=sender
http://www.thesamba.com/vw/forum/viewtopic.php?t=543116&highlight=sender
http://www.thesamba.com/vw/forum/viewtopic.php?t=353081&highlight=sender
http://www.thesamba.com/vw/forum/search.php?search..._chars=200