Speedo back lights.
Thread Starter
Three Wheelin'
Joined: Oct 2011
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From: Boston Burbs.
Speedo back lights.
Instead of posting 4 questions at once again, I am trying to simplify.
Anyone ever have just the speedo back lights not working? As I posted before, the other gauges light up. and this speedo does in another car. Ideas?
Anyone ever have just the speedo back lights not working? As I posted before, the other gauges light up. and this speedo does in another car. Ideas?
Thread Starter
Three Wheelin'
Joined: Oct 2011
Posts: 1,334
Likes: 4
From: Boston Burbs.
Bump! Anyone have any idea why the speedo will not light? I moved wires around and nothing. No separate fuse for the speedo lights that I can see. The speedo mph works. I am at a loss. The good news is I replaced two servos from my donor car today, and actually have a real HVAC system for the first time in a 964, cleaned out check valve on washer nozzle. Compressed air did the trick by blocking off the other sides hose with vice grips like when bleeding clutch. Also got my car inspected and alignment. So I done good. Now someone cure my speedo light problem Please!
Maybe someone can look at this wiring diagram and tell me what to check to get Speedo lights working. I am not much of a electrical engineer.
http://www.cannell.co.uk/_manuals/po..._electrics.pdf
Maybe someone can look at this wiring diagram and tell me what to check to get Speedo lights working. I am not much of a electrical engineer.
http://www.cannell.co.uk/_manuals/po..._electrics.pdf
Last edited by greg1990964; Feb 11, 2014 at 12:12 AM.
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Do you have +~12VDC @ pin 7 on the back of the speedo? If so the problem is internal to speedo. If you don't have +~12V @ pin 7 problem is external to speedo. Hope that helps. Looks like the drawings indicate that voltage comes from K1.
Thread Starter
Three Wheelin'
Joined: Oct 2011
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From: Boston Burbs.
Thanks for that info. I am electrically illiterate. Haha. I will try your suggestion, although I know the speedo lights up as I tried it in another car, and it does show speed driving. So somehow the pin that activates the bulbs is not working? Is that what you think pin 7 does? Powers the bulbs?
Thread Starter
Three Wheelin'
Joined: Oct 2011
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From: Boston Burbs.
I will go check pin 7 in a bit. A little frozen In my garage this am. If no power which I assume, I could always splice a jumper off another gauge for power. I bet tracing those wire behind dash to find the reason for power loss is not easy. I have no idea where K1 would be that feeds power. It is prob a short or disconnect from that I imagine as other gauges light up and K1 supplies power to other gauges.
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I believe K1 should be on the back of the fuse panel under the bonnet. Looks like K1 feeds power to all the gauges so if you have power to the lights in the other gauges you just have a solder joint under the fuse panel or bad splice somewhere on a GReen/BLue wire. Wish I could tell you exactly where K1 is but I can't find it in those drawings. Maybe someone with better eyes can see it.
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Thread Starter
Three Wheelin'
Joined: Oct 2011
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From: Boston Burbs.
Good to know that it could be under fuse panel. So it sounds like K1 under fuse panel would have a few power feeds coming off of it for all the gauges. Maybe I am best off by splicing over from another gauge? Never took fuse panel off, but I have to strip it out of my donor anyways, so I can learn on that one. I do lots of that and never break anything on the new car! Thanks for the help.
Thread Starter
Three Wheelin'
Joined: Oct 2011
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From: Boston Burbs.
image-3908784210.jpg
Missing pin on number 7 in plug for speedo. Soldered a pin to the wire from my parts car. All fixed. Thanks guys!
Missing pin on number 7 in plug for speedo. Soldered a pin to the wire from my parts car. All fixed. Thanks guys!