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Wed Nov 11, 2009 2:09 pm

last time my fuel guage was working but its not acurate so I swap the wires th on the tank then it suddenly it stop working at all. I checked the fuse,buy new vibrator,sending unit but still wont work, I try to checked the yellow wire if there is current but theres non. please help

Wed Nov 11, 2009 2:16 pm

vwsb74 wrote: last time my fuel guage was working but its not acurate so I swap the wires th on the tank then it suddenly it stop working at all. I checked the fuse,buy new vibrator,sending unit but still wont work, I try to checked the yellow wire if there is current but theres non. please help
Give us the background please.

Year of your car

What it was doing before you started messing with the fuel gauge.

Why you decided to switch the wires?

When it's hooked up, are you getting voltage out of either vibrator? With it hooked up, is there voltage at the output of the gauge itself? You can do this with a test light or a voltmeter.

If you replaced the vibrator, then it's possible that you burned up the gauge unit itself. But these tests will help us determine what's wrong.

Wed Nov 11, 2009 2:17 pm

I haven't had a working fuel gauge in over a year, so if you figure out the problem let me know. :P

I've just been too lazy to deal with it. I put gas in it every day I drive it, and I keep track of my miles, so it hasn't really beaten me yet.

Wed Nov 11, 2009 2:26 pm

okay, at first it was working but even at full thank the guage reaing was at 3/4 tank full only so I thought the wires on the tank area was wrong so I swaped them and when I checked the guage it went to full so I thought it was okay so I drove my car for two days and noticed the guage still full so I swaped the wires again and it went to just over 1/2 tank and when I drove the car it just wont read anymore.

I test the vibrator(black wire at the back of the speedo) there is voltage. the yellow wire at the back of the speedo near the vibrator,there is no voltage.
my car is 1974 super

Wed Nov 11, 2009 2:43 pm

guys please help, This my only car and I use my car daily for to work.thanks

Wed Nov 11, 2009 6:50 pm

vwsb74 wrote: okay, at first it was working but even at full thank the guage reaing was at 3/4 tank full only

Ah. You have a Super, which means you have the funky two-arm fuel sender. What's probably happened is that the upper arm is stuck, so that only the lower arm moves. I had the opposite problem; mine stopped at 1/2 a tank and didn't read lower, and then would suddenly drop to 1/4 of a tank.

Quote: so I swaped them
Ok, first of all, randomly swapping wires is a VERY VERY DANGEROUS thing to do. The Beetle has several circuits that are UNFUSED; randomly switching wires is a really good way to start your car on fire. The fuel gauge circuit is all protected by a fuse, so you shouldn't have this problem there, but consider that a warning. DO NOT randomly swich wires unless you know what you're doing.

By the way, if you haven't, take a look at the wiring diagram for your car. The vibrator is component "J6", the Gauge is "G1", and the sender is "G".

Quote: and when I checked the guage it went to full so I thought it was okay
Right. That makes sense, because you bypassed the sender and connected the gauge straight to ground, which means that it was drawing the maximum current, which sends the gauge to full. Possibly a harmfully large amount of current, but that remains to be seen.

Quote: so I drove my car for two days and noticed the guage still full so I swaped the wires again and it went to just over 1/2 tank

Right. So you restored the original (correct) configuration, it read normally again. Which would lead me to believe that you DIDN'T fry the gauge, however,

Quote: and when I drove the car it just wont read anymore.
So it reads empty all the time?

Quote: I test the vibrator(black wire at the back of the speedo) there is voltage. the yellow wire at the back of the speedo near the vibrator,there is no voltage.

Ok, the black wire having voltage means that the fuel gauge circuit is being supplied with power (no surprise). Now I assume with the key on, you held the meter on the place where the yellow wire is for at least 5 or 10 seconds, and it read no voltage during that time? If that's the case, then the vibrator or the gauge is bad.

There are two spade terminals that stick out of the back of the gauge. One is the one that the yellow wire connects to. The vibrator is plugged directly into the other one. It's sort of hard to get to in the car, but can you get a voltage reading from the connection behind the vibrator that goes to the gas gauge? If you can, read the voltage there. If you can see voltage there, but not at the yellow wire, then I suspect your gauge is bad.

Wed Nov 11, 2009 11:09 pm

http://www.nls.net/mp/volks/htm/fuel_ga.htm Go here and read. I went through this same process several months ago, do a search and read about test procedures for each individual component. Check ground or run a new ground wire. Just because you bought a new part does not mean it is good either, my new sending unit was bad out of the box, ohms readings were nowhere close to what they should be. I fried a fuel gauge while testing it by leaving it hooked to direct 12 volts too long, like 20 seconds or so, it really smoked !! Clean all contact points really good, they are old and corroded somewhat I would bet.Try to get in the mindset of finding the problem and fixing exactly what it is rather than just throwing parts at it, it is much cheaper this way. ANYONE can be a parts changer and eventually they will "fix" the problem. Keep at it and you will eventually be rewarded with a functioning fuel gauge, it is sure more convenient than writing down miles on odometer on a fridge magnet with plain white paper glued to it so you can erase at fill ups.

Thu Nov 12, 2009 2:14 am

The previous post is very good advice. Go to that excellent site and read and learn.

jim