VDO tach and fuel indicator not working

I just got my new VS home and everything works perfect except for the tach and the fuel indicator. I know that's just the way VW's are; it comes with the territory. Talked to Kirk and he told me that the red wire that starts in the wiper switch could be the culprit. I've tried to find loose connections but no results. I know some of you have dealt with this in the past. What could it be? Thanks!

If you have no signal at the wire going to the gauge check to make sure it is connected at the coil. Does the gauge work at all or is there nothing...ie no movement in the tach at all? If the gauge moves but not appropriately then it is almost definitely the gauge, but if you get nothing at all it is most likely the connection on the back of the gauge the wire going to the coil or the connection at the coil.

Fuel gauge you could disconnect the wire at the back of the gauge and again see if your getting any signal at all with the key on. Same troubleshooting tecnique as before first check for signal if you don't have any check that a signal is being produces by the sender and if not the sender is bad. If you have signal from sender but it isn't making it to the back of the gauge it is the wire in between.

Thanks for the tips Steve; I checked the coil connections (for the tach) and everything seemed in place. The tach doesn't move at all so, as you said, it could be that the gauge isn't getting any juice. I will follow your instructions and am confident will solve the problem. Thanks again!

check the connection now on the back of the gauge and with the car running check for electrical signal...if the signal is there your going to have to buy a new gauge....be careful you buy a reproduction gauge if the one you have is reproduction as the original is a different diameter for the opening in the dash.

Since both gauges are not working, it sounds to me that you aren't getting any 12v to the gauges when the key is switched on. This is what Kirk implied as he must send the 12v from the wiper switch. If you have a mutimeter check for 12 volts to any of the leads on each gauge.(with key on) It will probably be a common wire that goes between each gauge. The only other wires that go from gauge to gauge are the groundwire and the
gauge lighting.
Does the temp gauge rise when the engine gets hot? and do the oil pressure and generator light come on with the key? It could be a fuse.
I'm not sure how VS wires their cars.

BD

Gen and oil pressure lights work and the gauges light up when turning the lights on. The blue high beam indicator also works on that gauge but not the rest.

Ricardo if all else fails, Check with a mechanic before buying any new gauges. It still seems odd to me that both gauges would fail at the same time, especially since they are new. It still sounds like they are not getting power.(Or ground)

BD

An update: Yesterday morning I started the car and the fuel gauge is working now though I'm not sure if accurately; it's rather erratic; I filled her up and it only shows half full; it's weird. Tach still doesn't move. I'll definitely check it this weekend. The car is also running rather sluggishly and it seems it's running rich since it's smoking a little; I'm pretty sure it's just a matter of adjusting /synchronizing the Kadrons. I'll also work on that this next weekend. Apart from those little issues the car is a total dream. It's worth every single penny!!

Check your grounds! Then ask Kirk to send you a diagram of the gauges and make sure they are hooked up right. I had problem with the fuel gauge not working we put a new ground and it started working just fine. Yours could be loose.

Dick

Another update: I've taken the car to the service station to fill her up three times now and it seems that the float somehow gets better with use. This morning I filled her up again and now the gauge shows 3/4 full. That's an improvement over the first time, when it didn't move and showed an empty tank.

Hmmmmmmmm.........sometimes, in the past, I've had some new gas tank senders that seemed to have something coating the coil (there is a coil of resistance wire in there, made into an arc, with a wiper that's attached directly to the float arm wiping across that coil making the output resistance change with the level of fuel). It almost looks like some sort of anti-rust/corrosion preservative. Once the sender is run up and down the limits of travel (empty to full and back a few times) the wiper seems to wear the preservative off and it works OK after that.

After a while, I used to check them and cleaned them off with Carb cleaner and they worked much better - of course, that was before I installed them in the first place, but they're easy to pull out and replace if you want to take a look, Just mark the sender flange with a permanent marker as to which way is "UP" before you remove it, as the holes are not symmetrical all around.

gn

What you're saying makes perfect sense because the gauge seems to be working better after seeing some use. I'll keep in mind what you said about marking the sender in case I want to inspect it. As always, thanks for your valuable input!

I wanted to add that on the tach gauge, although the gen/alt. and oil pressure warning lights work, the temp gauge isn't moving either. Is that hooked up in Vintage Speedsters and is it supposed to work? If that gauge isn't working either maybe that could be the sign of a faulty unit? By the way, after adjusting the carbs slightly, the car is running so much better. I'm already getting ready for the first oil change at the 250 mile mark (as suggested by Kirk). I bought 40W Valvoline (that's the brand they use at VS, and that's the weight recommended by VW for our climate here).

I checked on the red wire that goes from the wiper switch to all 3 gauges and it's got juice. The connections to the coil are fine too; could it be that the tach is defective? Also, my temp gauge doesn't seem to work. Could both problems be related?

If this is a car under warranty....have kirk send a loaner to install and see if it gets rid of the problem.....if not you could pull the gauge and send it to North Hollywood place and have them test it for you.

Yes Steve, the car is under warranty, I just received it a couple of weeks ago. I'll see if Kirk sends me two known good gauges; that way I can find out if the problem is someplace else. As of now everything else is working just fine.

As far as the oil temperature guage- is the sender connected? If I'm not mistaken, VS puts the oil temp sender in a "tee" fitting with the oil pressure idiot light. If you are looking at the back of the car, it would be to the left, close to the center, down by the crank pulley under the distributer. I'm pretty sure the wire is light green. Ground the light green wire, and the guage should move to full hot with the key on.

Thank you so much for that tip Stan! I'll try it out! And yes, I see the extra connection on the oil pressure sender.

Yep Stan; did what you suggested and the gauge is fine; it goes to hot instantly when I ground the wire. Kirk told me that somehow these engines he's putting in the cars tend to run fairly cool so the needle doesn't even move in the temp gauge (and that's been my case). Kirk is sending me a replacement tach gauge; I hope this one works, and it should since everything in that gauge is working fine and getting power except for the freaking tach!!! Again, thanks for the tip!!!

Ricardo......your engine would have to be running less then 100 degrees in order for the needle to not move....I think this is impossible......try sticking a meat thermometer in the oil dipstick spot after drive the car at freeway speed for about 15 minutes. It will probably be in the 180-200+ range. This should be about the 3/4 mark on the oil temp gauge. If its not even close and your not getting any reading that a problem, because you won't know if you are developing a problem, if it is off a little it doesn't really matter because you will come to know what is normal for your car and if it starts running hotter you can recheck to make sure you aren't overtemping the oil.

Wow...now I'm starting to worry again.....and I thought everything was OK....

Shoot.....it all depends on what your sender is doing and how calibrated are THOSE? They tend to be all over the place.

On my car (with a dipstick thermometer) the temp gauge never gets off the left stop until it gets over 175 degrees, and the little line on the left side is about 190. If it goes up about 1/4 scale it's running about 220 - 225. I estimate the half scale point at somewhere around 250 or so (put a big red line well before there!)

Running around town (I'm at sea level, too) it hardly EVER gets more than 1/8 scale, and on a turnpike at 75 mph and 75 - 80 degrees outside temp it runs up to about 1/4 scale or a bit less.

The best thing to do (and a lot of people on here have bought one) is go to:

www.mainelycustombydesign.com/enginecomponents.htm

and order a dip-stick thermometer for a VW (P/N: 616 070 002 00).

Then you'll know exactly what's going on AND can calibrate your electric gauge pretty accurately with just a permanent marker.

Best $50 you'll spend this month!

gn

Gordon
I have my temp stick on order!!! Thanks for the information

Dick

I agree with Gordon, my VDO oil temp gage was showing 240 degrees at 70 mph on average days. Worried me and did some things to try to lower the temps. Then bought the temp gaged dip stick and when VDO was telling me 240 + the dip stick was reading 210 max. Yes, best $50 I've spent yet on the car.

Yup......

Now, if he only had one with BIG numbers for us geriatrics!

You know, Ricardo didn't mention how much it was raining when it leaked in.

I used to get to Puerto Rico during the "Monsoons" of February and, honest-to-God, I have NEVER seen rain heavier than that. It rains so hard that it hits the ground and bounces back up!

Well Gord; it was pretty intense but I've seen worse (if you could call it that since I prefer rain to drought)....

Another update: Just received a new tach unit from Kirk via UPS; installed it and voil