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Fri Jul 08, 2016 9:46 am

Replacing some bulbs on speedometer and this part was on top of it and the connector broke off. Would like to get a replacement but don't know what it is called and what it does??? Stamped on it was VDO and below that the numbers 50/5/1 at least that's what I can see.

Fri Jul 08, 2016 10:29 am

fuel gauge vibrator

Fri Jul 08, 2016 11:00 am

what is the purpose of this part? Is it necessary to have it?
Is it available to get?

Fri Jul 08, 2016 11:04 am

Yes it is necessary. And yes if it isn't working properly you can buy new ones on various websites.

It vibrates so that the fuel gauge needle works. Without it, your fuel gauge wouldn't move.

http://www2.cip1.com/ProductDetails.asp?ProductCode=VWC%2D113%2D957%2D099
http://www.airheadparts.com/Fuel-Gauge-Vibrator/item/113-957-099
http://bughaus.com/fuel1.htm
http://www.jbugs.com/product/113957099A.html

Fri Jul 08, 2016 11:09 am

Great thanks.

Will order one today. :D :D

Fri Jul 08, 2016 1:20 pm

Scorpwanna wrote: It vibrates so that the fuel gauge needle works. Without it, your fuel gauge wouldn't move.
Amazing. I've never heard mention of this before. Does it physically vibrate? What is the mechanism inside? Could this be the cause of so many people's gas gages not being accurate, like it's not vibrating strongly enough?

Fri Jul 08, 2016 2:47 pm

Sometimes it can be inaccurate because the sender rods on the sending unit are bent wrong. Could be a number of things. I just remember, when I was starting out with the bug world on my own bug the fuel guage sometimes wouldn't even work unless I thumped the speedometer near the gauge a few times and it would move toward full. I investigated and had to tighten up the connections on the vibrator unit and now it works. It uses "electrical vibration" inside the vibrator to allow the gauge to get the right voltage to move the needle to the right location. The more it vibrates, pulses or is given more power the higher up the needle goes. It's almost just like how the speedometer needle works. The tension of the spring holds the needle to the 0 position and the speedo cable from the tire pushes resistance against the spring forcing it to travel and unravel so to speak.

Mine is inaccurate as well because I need to figure out which direction to bend my rods. I just haven't done it yet. So at a quarter tank left, that means I'm really almost empty.

Again though, if the vibrator is working, there's no need to get a new one.

Fri Jul 08, 2016 4:33 pm

A great many of those vibrators have vibrated themselves to death.

The new ones (encased in black plastic) don't vibrate. The reason: because it has a light bulb inside that does the work.

The work the "vibrator" does is simple. It reduces the amount of voltage (to a little less than 50%) that goes to your gauge and sender rheostat; thus the slender wires don't burn out in those devices.

The new ones do this with a light bulb. When the bulb burns out, no power is allowed beyond, saving your tiny wires in the sender and gauge. The old ones, when they stopped working, had a tendency of allowing a full 12 volts to pass through, damaging the sender, as well as the gauge.

Tim

Fri Jul 08, 2016 5:19 pm

Here is an old discussion with pictures of whats inside the new and old versions:

http://www.thesamba.com/vw/forum/viewtopic.php?t=559244&start=0

The older vibrator style tends to suffer from metal fatigue after years of use, and can possibly fail in a way that puts full battery voltage on the gas gauge and sender, potentially damaging them.

The newer style actually regulates the voltage with a zener diode, the light bulb is used as a voltage dropping resistor.