Register now to get rid of these ads!

VDO guages I bought don't work ?

Discussion in 'The Hokey Ass Message Board' started by RDAH, Jun 11, 2012.

  1. RDAH
    Joined: Mar 23, 2007
    Posts: 465

    RDAH
    Member
    from NL, WI

    Bought them from Summit awhile back & just got them in my truck. They are electric & on sale = like 129 for 5 gauges. There's an "S" by one terminal for a wire to the sender & a "+" for 12v power. And the ground wire & light wire. It's a pain pulling this dash in & out. I have a half tank of gas, rejusters nothing. Zero on the oil presure, mechanical guage says 45 at idle. Voltage pegs the needle. Checked my wireing against the book & it's OK. Oh, the speedo works. Any ideas are welcome. I also ran a separite wire to the dash for ground = oooo
     
  2. I have to say it's the old "you get what you pay for" $129.00 is the price of a decent speedometer. I'd send em back and get your money back if you can, and if you can't chalk it up to a bad decision and get a good set. Gauges is not where you want to cut corners. The least amount of money I've seen a decent set for is around $329.00. Stewart Warner or Classic seem to be OK. I've had my SW Wings 6 gauge set in the roadster for 2 years now and they work great. I also prefer mechanical gauges over electric, I have not heard any bad reports on electric gauges, that's just my preference.
    Maxgearhead here on the HAMB just scored 6 SW gauges on Ebay for I believe $200.00, maybe PM him and get the details, I've seen those and they are new and real cool old style looking.
     
    Last edited: Jun 11, 2012
  3. Did they come with instructions and sending units? Or were the gauges expected to work with your existing units? Gas tank sending units come in different ohm ranges and if not compatible with the gauge, won't work. Don't ask how I know:).
    RB
     
  4. Send 'em back.

    I ran a set back in the '90s everything worked fine but the tach. I had them 2 years before I put them in and tested them (long story) I called Summit and they said send the tach back.

    I still prefer S&W and always have, mechanical is better for me that electric as well, but that is not he problem you are dealing with.
     

  5. I cannot believe they are all bad. I think you should check your ground wiring.
    I agree on the comment on the fuel guage. Use a sender that matches the gauge.
    If they indeed are bad I am sure they will be warranteed.

    ~Alden
     
  6. Aquaroscoe
    Joined: Apr 13, 2006
    Posts: 315

    Aquaroscoe
    Member

    I had the same issue, it has to do with the power and ground. They work with a floating ground, so if you just added the (+) and not a separate ground (I forget what lug), they won't do a thing.
     
  7. each individual gauge should have its own dedicated ground wire.
     
  8. squirrel
    Joined: Sep 23, 2004
    Posts: 47,921

    squirrel
    Member

    One wire for the whole dash? or a separate wire for each gage?
     
  9. VDO Instruments are very high quality, I have used them since I sold them at the shop I worked in back in the 1970's. I have them in my 37 Ford now. They are the OEM supplier for Porsche, BMW, Mercedes, VW, Ford, Jaguar, the list goes on.
    Some of their gauges use a floating ground where the sender has a separate ground wire, especially on the oil pressure. Others ground through the threads like other brands. Does your sender have one terminal or two?

    As for the fuel gauge reading zero, and the voltage gauge pegging, it sure sounds like a case of a bad ground or mixed up wires to me.
     
  10. ^^^^^ I agree with hotroddon^^^^ look at the wiring. I've run thesein a bunch of cars, make sure you have grounds on all the senders and each gauge.
     
  11. RDAH
    Joined: Mar 23, 2007
    Posts: 465

    RDAH
    Member
    from NL, WI

    I have ground wires on every guage running to the aluminum dash panel and a wire running from there to the steel dash. These VDO guages were made in Mexico. The last set that I put in my model A worked great, these are completely different in how they are wired.
    Aquarosoe mentioned a floating ground, whats that mean.?
     
  12. Put a tester on the ground post to insure you are actually grounded.
     
  13. cederholm
    Joined: May 6, 2006
    Posts: 1,621

    cederholm
    Member

    Someone correct me if I'm wrong, but a floating ground means you don't ground the gauge you ground the sending using. A typical gas gauge works in this manor.

    ~ Carl
     
  14. VDO does some neat stuff with their gauges and sending units. They offer sending units with variable resistance for the gauges AND warning lights.

    http://www.summitracing.com/parts/VDO-360009/

    Pressure Sender 0-80 Psi 1/8"-27 NPT 7.0 Psi Warning Contact

    [​IMG]

    Volt meters are pretty fool proof, the mention that yours is pegged and your other gauges don't work properly makes me believe you have a ground issue. Use a volt/ohm meter and measure across the + and - terminals at your gauge to confirm your gauge readings. A difference would indicate a gauge issue.

    Separate the lighting ground wires from the gauge wires, it shouldn't matter but it will not hurt a thing. I have seen feedback from brake/tail lights cause spikes and weird issues with gauges before.
     
  15. RDAH
    Joined: Mar 23, 2007
    Posts: 465

    RDAH
    Member
    from NL, WI

    The senders came with the guages & there is no thread tape where the temp or oil presure screw in. Only one wire on each sender. I'll let you guys know if I get this figured out. Thanks for the suggestions. THEY HAVE TO BE LABELED WRONG
     
  16. squirrel
    Joined: Sep 23, 2004
    Posts: 47,921

    squirrel
    Member

    The volt meter being pegged is weird...if it is not grounded, it should read zero.

    Could be the gages are junk....
     
  17. bangngears
    Joined: Aug 30, 2007
    Posts: 942

    bangngears
    Member
    from ofallon mo

    Depending on the wiring lit you use,i had the same problem.I elected not to use the ACC side of the ignition switch because it was a little 26 t roadster with no accessories,so low and behold i called the manufacturer of the kit i was using,told him the problem and first thing he says is did you hook up the ACC side of the ignition switch to the fues block on a certain terminal.Turns out he was right,i didnt use it and worked great after that.Not saying its your problem but you should have power to the gauges when you simply turn the key to on.
     
  18. RDAH
    Joined: Mar 23, 2007
    Posts: 465

    RDAH
    Member
    from NL, WI

    OK ELpolacko, I've seen some of your other posts & I think you know were the bear shit in the woods. So the dash panel is coming back out, thanks for the tech on trouble shooting them.
     
  19. 40FordGuy
    Joined: Mar 24, 2008
    Posts: 2,907

    40FordGuy
    Member

    Let us know how this works out, please...... A lot of us have VDO instruments, waiting to be installed... I'm going to change to individual guage grounds,....Thanks for that tip.

    4TTRUK
     
  20. I bought a set of VDO Cockpit Royale gauges last year and put them in my coupe, oil pressure gauge and the gas gauge didn't work. I double checked my wiring and everything was right, called VDO tech and we went through everything together and he decided it was the gauges (thought maybe someone had used the set for exchanges, etc.) anyway, I sent the two gauges back and after a 6 week wait I finally got my replacements. Put them in and it was the exact same thing, they didn't work. Needless to say, I was pissed! Wasn't going to wait another 6 weeks so I bought a new oil pressure sending unit (that's what I thought it was in the first place) and put it in and the oil pressure gauge worked. I pulled the fuel tank sending unit out and started looking it over and found that the hot wire was never soldered on inside the sender. I fixed that and now they all work fine. I had alway's thought that VDO was one of the best gauges around but now I'm not so sure. As far as thier tech's... well!
     
  21. squirrel
    Joined: Sep 23, 2004
    Posts: 47,921

    squirrel
    Member

    Traditionally, they were. The times they are a changin'
     
  22. Larry W
    Joined: Oct 12, 2009
    Posts: 733

    Larry W
    Member
    from kansas

    Quality control sucks!!!!
     

  23. I live for trouble shooting.

    I like to know why something failed etc. I have had similar happen before so what I would do in a situation like this is to get the whole panel working before installation.

    You might try and isolate each gauge individual just to verify. I have made up some wiring bits to help, three lengths of wire about two foot long. Alligator clips on one end and the appropriate connector for the gauges on the other. Then I can connect each terminal directly to a 12V + and - source and ground the other to each sending unit. You can swap the S and G terminals to see if they work.

    Look at this: Notice both diagrams show grounding the lights separately from the gauges.

    [​IMG]

    [​IMG]

    [​IMG]

    This guy has some interesting issues

    Also this:

    I know you said there was no teflon tape, but is the sending unit getting a good ground? Check the Ohms resistance between the sender and the "-" post on your battery, should be really close to 0 Ohms.
     
  24. Aquaroscoe
    Joined: Apr 13, 2006
    Posts: 315

    Aquaroscoe
    Member

  25. RDAH
    Joined: Mar 23, 2007
    Posts: 465

    RDAH
    Member
    from NL, WI

    Finally got back at the guage problem. I'd rather rebuild a motor than screw with wiring once installed. Printed out hatroddons test sheet = thanks. Tested the senders = ok took the dash back out for a 3 time. tested wires coming to the gauges & getting pretty close to the same readings as at the sender. Put the dash on the bench, checked my wire job = OK. Started testing my grounds & wtf I have a ground on the power wires. Took one off at a time & found the power & ground that were on the light for the speedo are shorted. I replaced that light socket & now they all work. Should'nt that have blown the dash power fuse ?
     
  26. Path of least resistance.

    You do know there is magic smoke in the wires that makes all this shit work, right?

    [​IMG]

    Some systems leak out the smoke instead of blowing the fuse as in your case.

    :D
     
  27. RDAH
    Joined: Mar 23, 2007
    Posts: 465

    RDAH
    Member
    from NL, WI

    Didn't print my last post. Long story short, the light for the speedo was shorted to ground. Replaced that socket & everything works now. Don't know why it never blew a fuse.
     
  28. Cool that you reported back, Might help someone else. I knew it had to be something like that as VDO is good Chit.
     
  29. RDAH
    Joined: Mar 23, 2007
    Posts: 465

    RDAH
    Member
    from NL, WI

    I see that jar of smoke has the Lucas name on it. I always heard they are the company that created darkness.
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.