New to me Speedster, can't get the VDO gauges to work?!

Hi Roger,

for me it seems, as if you will not have any problems with this gauge in the future anymore, cause you shoot it to death now :-(

I made a research in our german forums about this RPM gauge; they say, it is a gauge for a "HKZ - Ignition" (this means translated High Voltage Kondensator Transistor Ignition). It should be connected to the Ignition Box of the 914/911 and not to + or - of the coil.

in the forum, they sayed, if you do this, you killed the instrument within a second...

So I hope, I`m not right but it seems...

cheers Jan

None of the 914's had electronic or even CD (capacitive discharge) ignition - just plain old contact points and condensor.  914 gauges are frequently used in VW and replicas (IM used them for years) so it will easily work.

Try this for back of gauge wiring help:

http://tinyurl.com/h83pqgm

Hi Roger, Hi Wolfgang,

Attached, you find a picture of the "box", I was talking about.

As I found out, it is not needed on the old gauges but the newer 914/911 ones won`t work without. And without it the gauge might be distroyed... (I only reply, what the Porsche guys told me).

WOLFGANG posted:

None of the 914's had electronic or even CD (capacitive discharge) ignition - just plain old contact points and condensor.  914 gauges are frequently used in VW and replicas (IM used them for years) so it will easily work.

Try this for back of gauge wiring help:

http://tinyurl.com/h83pqgm

 

Thanks Wolfgang that's relieving news. I actually have that very same schematic issue is the wiring in my car is not color coded correctly so i'm trying to determine which input on the back of the tack goes to what. I even disconnected the tack completely and hooked it up directly to the coil and 12V and negative in the back of the car and still got nothing. The illumination of the tack were working but that's it. Based off the diagram could you tell me what each corresponding color runs to? Thanks for the help, i'll be glad when this is sorted.  

Does anyone know of a way to bench test the tachometer to see if it's still working? I'm fairly certain I have it hooked up correctly from the diagram Wolfgang sent, i'm wondering if instead of faulty wiring it might be defective. Tac appears to be brand new however i', not certain given that I had no info from the previous owner. 

is it time to contact the fellows at No Hollywood Speedo, and ask them?? I'll bet if yu sent the tach to them, they would be able to explain things.  Maybe just a phone call?? I am sure they have a way to calibrate these things. Maybe "sure" was too strong, perhaps "guess" would have been a better choice.

Volksrod site says: 914 -4 tach has 3 terminals on the back 12+ goes to any 12 volt supply .... 1 goes to the coil #1 terminal ... and  - (neg) goes to ground.

I had a '72 914 but never messed with OEM wiring.  I did add a DELTA Capacitive Discharge system and had to add resistor to wire to + to eliminate tach bouncing around.  

I'd think getting another used 914 tach would be cheaper than sending it off for repair.

Greg, just trying to learn something here. Is the coil #1 terminal, the source of the "data" RPM's in this case?

art

yes, the + terminal on coil

Roger, if you should go looking for a replacement, I see several inexpensive ones on ebay, and expensive ones.  There is a difference, for various model years of 914's.

If you look up into the top of your tach face, you will see a 914 part number.

Art

They are same internally (except for the rare 914/6) - some have a silver center button ('70-73)  and later ones a black center button - Plus later models have plastic lenses that scratch real easy. (If gauges are same year all OEM ones would have had silver or black button.  The plastic lenses can be replaced with the glass one.  

http://www.p914.com/p914_gauges_cluster.htm

Thanks everyone, Wolfgang based on this description I must have a 70-73 since the center button is in fact silver. I'm going to test with this configuration tomorrow I'm not certain I had ground connected correctly. I believe these gauges came in a set when the kit was purchased. They look new and the odometer only has ten miles on it . I'm hopeful this will work. Thanks so much for all the replies. I'm on a learning curve here. 

OK so I was able to get out to the garage this morning. I hooked the positive 12V directly up to the battery positive. I hooked the ground directly to the negative of the battery, and the 1 terminal to the + side of the coil started the car and got nothing. I guess i'm in search of a new tachometer unless I messed something up there. Does anyone have any used tachometers that will fit in the stock VDO gauge hole? Doesn't have to be VDO gauge or in great cosmetic shape just one that works and fits, preferably inexpensive, I figure I can always upgrade later. Thanks for the help, wish I had better news. 

maybe send it to N Hollywood and see what they say.When i had speedy from Kirk he was using Chinese tachs, went thru 3 of them (his dime) he finally sent me one that was rebuilt at NH, worked perfect till i sold car..

wrote: "and the 1 terminal to the + side of the coil started the car and got nothing."

The signal line of the tach should go to the - of the coil. I should go to the same point, where the interrupter is connected. 

Have sa look If it  is connected to the same side of the coil, where there is also connected the line going to the distributor. Oterwise it seems to be wrong...