Early Bus Fuel Gauge

[hambone]

Hi, I have a '70 bus with the engine and trans out. I want to check the fuel gauge, is it a bad idea to hook up the battery and turn the key with all the loose wires and missing stuff?
THANK YOU

[Amskeptic]

Hi, I have a '70 bus with the engine and trans out. I want to check the fuel gauge, is it a bad idea to hook up the battery and turn the key with all the loose wires and missing stuff?
THANK YOU

Not a bad idea if you have common sense. Do you have common sense?

Visegrip the battery cable to starter solenoid end and the fusebox feed wire end together and allow to hang free of fuel line and its clamp (which best be dry and not damp).

I do it all the time so I can listen to the radio when the engine is out (in a garage only, not out in the beautiful countryside)
Fuel gauge test needs gasoline in the tank to keep the resistance windings cool. Did I tell you that a consistently full tank lets the sender last for over 588,238 miles and thirty six years easy?
Colin

[asiab3]

Skills on the Samba said he went through six new early bay senders before he found one that worked. When I installed mine, I crossed my fingers and said a prayer to the ghost of Heinz Nordhoff. Sure enough, when I pulled out of the filling station, I showed "R." BUT over the next hundred feet or so, the needle gradually rose up. My point is, I think a new early sender needs a tiny bit of tough (and wet) love to show accurate readings.

(Edit: I know you're testing an existing one, but I hope this helps if you or anyone else end up replacing it.)

Keep your #15 ignition wire free of compartment metal... When the music started to smell, I knew why ;)

Robbie

[wcfvw69]

http://www.thesamba.com/vw/forum/viewto ... highlight=

Here's a thread I started on The Samba about 70' sending units. As mentioned, I bought the Bus Depot VDO (Brazilian) sender.

It's been installed for several months. The only issues is the fuel gauge needle bounces a bit and the gas gauge reads a quarter tank low meaning when the tank is full, it reads 3/4 of a tank. I'm not sure if it's the sender or gauge.

[Amskeptic]

The only issues is the fuel gauge needle bounces a bit and the gas gauge reads a quarter tank low meaning when the tank is full, it reads 3/4 of a tank. I'm not sure if it's the sender or gauge.

A common affliction of buses, that long trip from the gauge to the tank adds resistance, but at least the error helps you not run out of gas.
Colin

[wcfvw69]

The only issues is the fuel gauge needle bounces a bit and the gas gauge reads a quarter tank low meaning when the tank is full, it reads 3/4 of a tank. I'm not sure if it's the sender or gauge.

A common affliction of buses, that long trip from the gauge to the tank adds resistance, but at least the error helps you not run out of gas.
Colin

I was "hoping" there was a cure or adjustment you or someone knew of on the gauge. Did brand new bus's back in the day have gauge needles that bounced and were not accurate?

[Amskeptic]

The only issues is the fuel gauge needle bounces a bit and the gas gauge reads a quarter tank low meaning when the tank is full, it reads 3/4 of a tank. I'm not sure if it's the sender or gauge.

A common affliction of buses, that long trip from the gauge to the tank adds resistance, but at least the error helps you not run out of gas.
Colin

I was "hoping" there was a cure or adjustment you or someone knew of on the gauge. Did brand new bus's back in the day have gauge needles that bounced and were not accurate?

There are two different styles of gauge. The early ones had a vibrator. The needle would jump to position the instant you turn on the ignition. The later style gauge slowly creeps up to position. The early style gauges were susceptible to jumpiness if the connections are not secure to the vibrator and the gauge as well as the ground terminal ahead of the firewall. They are completely less adjustable at the sender than the later style ones which I calibrate before sticking into the tank.
Colin