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98 Blazer - Odometer unlit


Xcrewchief
07-27-2009, 10:23 PM
Okay, 1998 Blazer 4x4, 4.3...Odometer (for a while) was working intermittently, now it is completely unlit. Have checked fuses to no avail...Also have no indicator light showing what gear I'm in (automatic). Any help sure would be appreciated...
(As an add-on) Everything else works, all fuses are correct amperage and in the right places. These are the only two things that don't light up. Could it possibly be a bad connection somewhere on the back of the speedometer/odometer? Once again, thanks.

Mark1950
07-28-2009, 06:56 AM
One possible problem is a cracked solder joint on either the odometer or PRND321 circuit board connector. I found mine on the 9 pin connector of the PRND321.

Xcrewchief
07-30-2009, 08:19 PM
Thanks for the response...Now a question to make me feel like an idiot..How do I get to that connector? I have a little knowledge about taking the dash apart, as I had to remove some pieces to install a remote starter a couple of years ago. And before you ask about those connections, I even went back and made sure (before I posted here) that nothing that I installed was shorting out against anything else...
Thanks again

Mark1950
07-31-2009, 07:17 AM
The instrument cluster needs to be removed.

I used a 7mm hex head socket to remove the hex screws that hold the Instrument cluster in place (the dash around the cluster will need to be removed). Unhook the 12 pin connecter as you pull the cluster out (be careful of the flasher button on top of the steering column).

With the cluster out – carefully remove the plastic framing and the plastic around the two small circuit boards behind odometer and PRND321. You should see a white 9 pin cable on each board.

I just resoldered all the pins - both sides.

Just to confirm - before you resolder you might want to look at the solder connections with a magnifying glass to see if there are any cracked joints.

Good luck

Gabe25
08-01-2009, 04:45 PM
You mite find this helpful. Step by step how to replace the instrument panel lights. Here's the link.
http://www.automotiveforums.com/vbulletin/showthread.php?t=379971

Xcrewchief
08-16-2009, 12:12 AM
Thanks for the advice, and now a follow-up....
Pulled the instrument panel out and took it inside the house and carefully took it all apart. Inspected for any signs of a cracked board or any bad soldering and couldn't find a thing...Then took just the circuit board out and plugged it back in to the connector and it magically worked again...
I have NO idea what it was that was causing it, whether the connector wasn't firmly seated, etc. but it now is working just fine (for now?) and I can chalk up "How to remove and reinstall the instrument panel" to my list of things I can do now....lol
Again, thanks all that answered!

Gabe25
08-16-2009, 09:00 PM
Glad to hear that you fixed the trouble. To bad youreally couldn't pin point the actual cause in solving, but it does sound like you just had a bad connection. Thanks for posting back. Hapy motoring.........

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