Welcome to the Corvette Forums at the Corvette Action Center!

Digital dash 101

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Inside of the dash??.

There are 4 882 halogen light bulbs 84-88 which provide back lighting for the LCD displays... There are NO LED?s in the dash..... The 89 has different style bulbs.

The 882 bulbs are a halogen Bi-Pin bulb.. Do not get your greasy mits on the bulb or risk doing this again! The 882 bulbs are about 14 watts.

Most of the 84-89 dashes I have rebuilt need new sockets for the light bulbs , it's usually pretty toasted in there.

I would HIGHLY advise removing the dash and see what you have inside.
If your not technically inclined...have it done....

In 1989 they switched to the same light as in a normal Chevy dash (Like in the drivers info panel, larger, less wattage) . There is a 10 watt version of that bulb (Stanley 7073) and using this setup instead of the 882?s. The trick is going to a good auto parts store or junk yard and finding good lamp bases. The dash is a bit dimmer but will last longer, and your wallet will not be as light!

Removing bulbs from the front??.

I've found in the past 882's that have been in for a while are a bear to get out (through the front) and if the sockets are bad when you push the new bulb in. they disintergrate. If the sockets are ok the that is a good way to go, the Mid America kit comes complete with a hose & push stick & new sockets all that for $50.00 deal huh? (Plus s&h)

The few & the brave??.
You ?ve decided to venture into the DASH ZONE
This is a good link to removing the dash electronics out of the dashboard!

http://www.corvettemagazine.com/2001/January/dash/digidashpg1.asp

Assuming you have the back tin panel off already?

Inside the guts, there are 2 main boards
The top most one the input / output board.
The top board has the cruise control.
odometer drive circuit. Changes in this include the odometer wiring from a 2 pin red connector to a 3 pin black connector.
5-volt regulator for the CMOS chips. In 84-87? This was on a separate daughter board
later it was incorporated into the PC board.


To remove the top board there are 6 screws.
Remove the screws, and carefully lift the top board.
If your just replacing bulbs STOP HERE! Remove the old bulbs, clean the bulb connection points with an eraser ( like on the end of the pencil)?.Replace the bulbs.

The top board has a 12 pin molex style connection (female) and the bottom board has a 12 pin male

This connection fails due to poor spring contact, it builds up resistance over time.. which generates heat & melts the connection point.. No back lighting anymore, Boo Hoo!

In extreme cases the pins get so hot they slightly melt the solder connections on the lower
(Male) pins on the board. And you usually get the following

I beat on the dash? the lights come back on.


If your brave & bored.. Continue
The bottom board
Has the display electronics on it
Has the 882 sockets on it.
( there are a few flavors of this board which relate to the TACH functions)
The 84 style
The 85 with the X10 X100 display
(So 950 rpm shows up as 95 as opposed to 9 in the number window)
And the later models with Upshift and Upshift for best economy
The O/D display ( for 4+3?s)
And in 89 the 1 to 4 display


Now a warning here, If you are not careful past this point you could damage the glass LCD elements render the dash useless!

The bottom board has the connection points from the bottom of the Printed Circuit Board via the "Pink Pearl eraser contactors" ( pause for effect)

The current flow comes from the boards VIA the "Pinkies" and directly touches the edge of the glass LCD elements?. Over age & time the "Pinkies" stick to the glass & to the PCB?s?..

There are about 16 screws that hold this assy together.

Carefully lift this board up while holding the black plastic Pinkie holders down.

If you lift the glass you will have to disassemble the entire light diffuser assembly & re assemble.

Resolder the 12 male connections on the PCB, & slap it back together.

Cool Pix & Info
http://www.batee.com/corvette/index.shtml

To be continued, btw I posted this novel here so other's wouldn't have to go hunting for all the informational bits scattered thru the different posts.

Mike
 
digital dash 101 1/2

Mike, I replaced my 882s with 168s this summer for a whopping total of 6 bucks with no difference in brightness of the dash. It took about 45 minutes to do the whole job.:beer Barry
 
45 minutes??!!!! WOW

Total R&R for the dash
Including pulling the board & replacing
bulbs & sockets
My you are fast!

168 are good bulbs BUT they are a little dimmer, but certiainly less expensive.

It's at the point most people can't tell.

Mike
 
Yes there is

Mid America sells it
(and others)
By Gordon Killabrew ( sp?)

Ecklers
Part #35756
$31.99

www.ecklers.com
 
Thanks Mike , thats the one.
My dash ,85, go's blank and then comes back on ,maybe if it wants to . And its quite eradic with its read out. Just the speedo and tach. Gauges are ok ,but cant see them when the dash go's out. Hard to explain.
 
Backlighting

Is it?
A) All the backlighting goes out but if you look at the dash at the correct angle you see that the gauges are actually working.

B) You can always see the gauges but some areas are brighter than others

C) When the lights go out, I can see something weird is happening on the gauges
and it's a jumble of information.

D) It goes out..I pound on the dash, some lights come on..others don't when the lights come back on there is gibberish for a second and then it straightens out and 2 seconds later it goes out again. And there is a huge depression on the top of my dash pad.

Mike
 
Thats it.....all of it.....including that rap on the dash :eek.....Well ? What is the diagnosis?.....ole dash doctor.....:D
 
Take 2 of these

1) Molex connector
2) Maybe bad ps board on back.

Gotta pull it to be sure.

Or... pull it, ship it to me $165.00( ish)
and I'll get it workin like NEW!

Mike
 
Its on my list . When it is time I will talk to you further. Would really like to have it gone thru and start fresh. The taking it in and out part is a drag. Thanks Mike.
 
Well not to bad to remove

Read the first posting it has a web link for just the removal part
( pretty color pictures )


Mmmmmm Good

Mike
 
Ok cool.....I have that link in a file for future use.
I'll getter out . Nooo problem....aint skeered.......
:cool


Thanks
 
Nothing to fear

Cept fear itself...

( and where did all these wires go.....?)
Mike
 
"Anything is possible , the impossible just takes longer"

Wires ?? those are extra . Like extra parts . posta havem. :eyerole
 
Wires

Are NOT good in excess in Corvettes.... I took me 3 days to rip out 3 different versions of Alarms 2 different stereo hookups and other mystery flashing lights ( not to mention 7 different earrings jammed up in the passenger gear track) .

And the previous owners Girlfriend liked sunflower seeds & coke.


Do you have ANY idea what a mess that leaves under the seat!


Mike
 
Sunflower seads and Coke....musta been tough on the nose...what a gal!!!......Oh whoops , the sticky kind.
Yea some people are tough on cars. I 've found some interesting items under seats and in consoles . Legal and illegal.....lol
Some of the aftermarket gizmos of a few years ago were quite the deal .:eek. I've seen some amazing owner installed messes. My 85 has 114,000 unmolested miles. I was relieved to see all original pieces thruout and amazingly clean too.. hasnt seen any bad weather. Maybe I got lucky on this one.:)
 
In My 84 Under the seat part Deux

I found 6 rounds of 44 mag hollowpoints.
The expired drivers license of one of the previous owners.
7 parking tickets ( to same person)
and 4 empty vials
Yikes
Talk about a colorful history!
I thought dealers( used car ) were supposed to check this stuff out!

Mike
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Advertise with the Corvette Action Center!

Double Your Chances!

Our Partners

Back
Top Bottom