New guy needs HELP!!

Topic: New guy needs HELP!! (Read 2881 times) previous topic - next topic

New guy needs HELP!!

Reply #15 – May 31, 2007, 11:28:47 PM

both screens get ther power from the same wire. it is on the clip behind the tripminder pod (brown clip). the power comes in and goes into the speedo and then is sent from there to the tripminder pod. so if both are out the problem wouldbe in the speedo.BUT, you said that you swaped out with another cluster and the same happened. so this would mean that the problem is not in the speedo or the circut tape. the problem is in the wires. and you know it's not the fuses or the whole thing woon't work. so what you have is either the power wire has burned out or got cut or the ground did what you needto do is take a multi meter red side to the power wire on the brown clip position #17(light green/yellow wire) and then ground the black side of the multimeter to the frame(ilike to use the steering columb for the stuff by the cluster) turn on the key and see if you get 12v if you do it's good if you don't the wire is bad and you'll either want to trac it down to see wher it went bad or run a new one. if it's good then your ground is probably bad but to check it is all you have to do is put the black sid of the multi meter on the ground wire wich is on the brown clip position #18(black/light green wire) and then touch the red side to a power i'd go with the power for the tach side since you know it works and it's right there. it's located on the other clip position #14(Light blue/pink) then turn on the key and you shold get 12v if you don't it's bad and you'll want to track it or run a new one. but it should be one of those two wires. as long as you don't have any display at all when on. if there is a ghost display when on but it looks like the light is off then it's the illumination wire #12 white/light blue. happy hunting. if these don't work give another shout out and we'll go from there.

New guy needs HELP!!

Reply #16 – June 01, 2007, 01:00:43 AM

to troubleshoot the display under normal situations where there is a display and numbers are present,, go to my DIY link above my sig.

In your situation,,,
The 87 shop manual 33-5-15 step 2 calls this fault as
"Display backlighted but blank", go to pinpoint test TB"

so,,,,,,,,,step by step

in a nutshell so i can make the novel before me become a summary,,

they say to unhook the battery
remove cluster
reconnect battery
turn on ign sw
check pin 14a is equal to batt voltage (min 10v)

next
check continuity from pin 15a all the way up to the bat ground cable
check for continuity from circuit 687 side of fuse to ground
check for blown run fuse on circuit 687

looks fairly simple but other than a power or ground issue, the manual calls out to replace the module. since you swapped out the cluster,, it rules in the fact you have a wiring issue as stated.

so,,, has anyone had a sterio system installed in this car recently,, do you notice any "hack job" going on with the wiring?

Also,, from what i have noticed, along the bottom of the actual speedo module itself, there is a narrow piece of flex print running into the module. I damaged mine when i pulled it out and had to solder in jumpers. Im laying money on that is where the problem is because i had the same issue, no number but i had background illumination.

scott

New guy needs HELP!!

Reply #17 – June 01, 2007, 08:04:16 AM

Raser & Scott,

Thanks, will use this very helpful information and get back to you.

Regards,

Tony P

New guy needs HELP!!

Reply #18 – June 01, 2007, 01:13:26 PM

no problem .if its not the wires then scott is probably right that the circut tape is the culprit but i would'nt think so sine it was bad on your replacement one too. but if it is just look on the tape to see if you can see any gaps in the circut line if not just fallow it from where the clip plugs in for the power and the ground to the bottom of the pod and check continuity through the circut tape. when you handle these tapes you have to keep in mind that they're 20+ years old and are usually pretty brittle. i don't like to futzs with them any more tan i have to.by the way rogers the name for use in the future.

New guy needs HELP!!

Reply #19 – June 03, 2007, 01:41:32 AM

below is the fragile flex print portion i spoke of. It is easily snagged bent up or snagged when the cluster is removed. I had to steal this pic from bondocougar but as you can see, even this unit is showing the signs of bent flexprint.

This area with the red arrow is where i had to solder in jumpers to make my numerical display work again.

New guy needs HELP!!

Reply #20 – June 04, 2007, 08:12:44 AM

To Roger, Scott and the rest,

Many thanx for your comments and suggestions!

Success!!!! The digital Instrument panel has been repaired.

The problem was in the Mylar circuit strip from "B" connector to the speedometer. There is a retaining pin that protrudes from the speedo through the rear I/C housing that is used to retain the mylar circuit strip, if the strip shifts it can become pinched on the pin and, as was previously stated these are 20 years old and somewhat brittle, cause the circuit tape was broken on both my original (ground & power) and the doner (power).

Was able to find this by simply using a multimeter to test for continuity from the plug contact area of the strip to it's terminal on the circuit board (see Scotts foto).

Installed two jumpers and was good to go!

Thanks again!

Tony P.

New guy needs HELP!!

Reply #21 – June 05, 2007, 12:45:51 PM

glad to here that you found it enjoy the car!!