dewjrman

Half the digits on my DIC stopped displaying last week but everything else works on the instrument panel.

I looked for used IPC's on websites and Eb but I'm finding a shortage of my part number in my mileage range. My car is a 1998 automatic (non-HUD). GM PN is 10411393 and code NAX.

There is a bunch of 6 speed IPC's for sale, PN 10400361 code NAM. There are also some NAC panels available.

I've had the dash out before and I'm comfortable working on electronic hardware. I saw how to replace the IPC circuit board in post 1570380674.

My question is can I swap the circuit board from a 6 speed (NAM) into my automatic (NAX) and have everything work okay? Worried about vehicle speed and possibly mileage accuracy.

DewJr

dadaroo

I am not aware of any difference in auto and manual IPCs. HUD versus non HUD does matter. Even my GM parts book shows no difference. Curious where you are getting otherwise.

The large green board contains the mileage which can be reset by the dealer or others.

With that said, why do you think it is a board issue and not the actual display? More likely it is the actual display from my experience.

dewjrman

Hi, thanks for responding.

I haven't torn it down because it's my daily driver. From the 6th picture in the post here:
https://www.corvetteforum.com/forums...post1570380674
I thought the display was part of the big green circuit board. The drivers for the display are definitely on that board and are probably the culprit.

wbrands

The display is indeed part of the PC board and your mileage is coded into that. As far as the speedometer, that is fed from the BCM where the "gearing" for the speedometer is stored and can be changed/corrected with tuning software such as HP Tuners.

When I changed mine on my '98, neither the dealer or anyone else local could reset the odometer reading. Had to send the PC board off to have it reset to match my old board. I used Prospeedo (www.prospeedo.com) and they could work with just the PC board sent to them but they were pricey (about $300 IIRC). Check with them and with ASAP Speedo (http://asapspeedometerrepair.com/product) if your dealer can't/won't do it.

Bill Curlee

The display bulbs are UNDER the green board on the display / gage board. Do you realize that most of the gage display that you see is illuminated by florescent black light tubes on either side of the gage cluster? If one of those black light tubes isn't working, only half of the display will glow.

The bulbs on the display board are mainley for the information displays.

Turn the key on at night and look in the corners of the display for a 4" long black light with a mirror reflector and see if BOTH lights are lighted.

Hope this helps/

IF, neither of the black lights are bright, the high voltage transformer is most likely NOT functioning.


Bill

dadaroo

What I had meant to suggest is to try and replace the display on the board and see if that works. That would keep your mileage. Lots of pins so it would not be easy.

dewjrman

Thank you everyone for the information. I will buy a used 6 speed IPC. I just well throw the whole panel in there and see what happens before I start swapping components. I'll post back with the true failure mode and status of the test.