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Technical => Electrical Tech => Topic started by: Canuck on November 05, 2004, 06:14:06 PM

Title: Digital speedo trouble
Post by: Canuck on November 05, 2004, 06:14:06 PM
I have an 88 T-Bird with a digital speedo, problem is no numbers are being displayed, does that mean it is junk, or could it be repaired. Any help would be great, thanks.
Title: Re: Digital speedo trouble
Post by: black ct on November 05, 2004, 08:23:13 PM
Is the speedo pod lighting up with no numbers or not lighting up at all?  If there is no light check to see if the numbers are there but hardly visible. If so it's just a couple of bulbs. Otherwise it could be a bad connector or a bad gauge cluster.

 good luck
Title: Re: Digital speedo trouble
Post by: cougarpower51 on November 05, 2004, 11:52:48 PM
In my opinion I think your problem are bulbs :bs:
Title: Re: Digital speedo trouble
Post by: Bird351 on November 06, 2004, 06:53:24 PM
Sorry to hijack but this may be a similar issue.

With the exterior lights switched off, you can barely see the digi-dash at all during the daytime. Even the interior lights are enough to wash it out. However, kick even the parking lights on, and the digi-dash is perfectly readable.
Title: Re: Digital speedo trouble
Post by: amooset on November 06, 2004, 08:14:58 PM
It's junk, buy a replacement ;) .  J/k I dunno if it is or not, but if it's not displaying numbers anymore, that may be a pretty serious problem.  I've got one for sale if you determine that it is broken.
Title: Re: Digital speedo trouble
Post by: bondocougar on November 06, 2004, 10:50:24 PM
Bird351,

That sounds like some bulbs are out, as when you turn on the park/headlights some extra bulbs are activated to better lite the dash at night.  These add the backliting to the dash that you are missing since the primary bulbs are out.
Title: Re: Digital speedo trouble
Post by: black ct on November 07, 2004, 07:53:13 AM
My digital speedo has only two bulbs per pod (speedo being one pod with two bulbs). The dim feature is controlled by the dimmer circuit (on the headlight switch) with a rheostat that's activated by the headlight switch because both lights are used whether bright or dim, not by extra bulbs. If your dash lights only work when headlights are on (or vice versa) then maybe you should check the operation of this circuit. Again, check the connector at the back of the dash for light circuit power with headlights on/off. Also check the headlight switch. Come to think of it, wiggle your dimmer switch before you try anything else - maybe it's just a dirty rheostat.
  Now that I've done all this thinking at the keyboard, I'm pretty sure you would have to have a headlight switch problem to get power to the dash lights only with the headlights on.

 Good luck! Hope this helps.
Title: Re: Digital speedo trouble
Post by: PAULD on December 04, 2004, 06:08:03 PM
Try rebooting your speedo. Disconnect the ground cable on your battery for 10 seconds and reconnect. I've had problems with my speedo before and this always works.
Title: Re: Digital speedo trouble
Post by: Thunder Chicken on December 04, 2004, 10:11:46 PM
If the dash lights only work with the parking lights on the problem is in the cluster illumination relay. It's in the center dash stack, behind the radio/HVAC area. Remember the basics: If a bulb works in some cirspoogestances (park lights on) but not in others (park lights off) the bulb is not burned out.
Title: Re: Digital speedo trouble
Post by: Bird351 on December 04, 2004, 10:20:56 PM
Actually, more than half the lights in the dash failed a continuity test with my little Radio Shack tester.. including the two pointy-tipped bulbs in the orange sockets that don't quite hold the same bulbs as the other large ones. (most of the other failed bulbs were those tiny little ones I had to use duct tape to pull out of the sockets)
Title: Re: Digital speedo trouble
Post by: 88WhiteCat86 on December 17, 2004, 03:46:34 PM
Canuck,Have you had your tranny replaced? A friend had his tranny done and they didn't hook up a wiring harness they were suppsed to and that happened.
Title: Re: Digital speedo trouble
Post by: Cougar5.0 on December 18, 2004, 04:06:50 PM
Quote from: Bird351
Actually, more than half the lights in the dash failed a continuity test with my little Radio Shack tester.. including the two pointy-tipped bulbs in the orange sockets that don't quite hold the same bulbs as the other large ones. (most of the other failed bulbs were those tiny little ones I had to use duct tape to pull out of the sockets)


There are relays under the dash as described. I had the exact same problemas you but I just switched two relays (there are two or three under there) and everything worked fine after that. The relays are up under the dash in the area between the electronic dash and radio. Turn on lights while feeling up there and you will feel the relay operate.
Title: Re: Digital speedo trouble
Post by: jcassity on December 23, 2004, 08:19:03 PM
i took everyone of my sockets and bent the metal contact just so to help continuity.
also, i bent out the little wires on each blub just a little and reinstalled em back with some conductive compund.

a lot of times you will notice the sockets really dont make good contact until you fool with them a little bit.