HELP!!! c4 digital dash harness

stick105 · 03-17-07, 12:51 PM

HELP!!! I am in the middle of cleaning the contacts on my1984 digital dash. I got the cluster out and noticed 2 ports for a wire harnesses on the cluster but only unplugged the top harness there wasnt a bottom harness plugged into the cluster. I have spent 3 hours and tore the entire dash apart trying to find the missing harness. Can anyone give ideas as to where it could have gone or even if there are indeed 2 harnesses that plug into the cluster , man am I flustered

Thanks in advance

3dale1 · 03-17-07, 06:08 PM

There are two on my 85. One goes to the DIC, I am only guessing that the other goes to the computer.

Did your dash work correctly, and has someone swapped engines or the engine management system on your 84 (carbed it or gone to TPI?)

stick105 · 03-17-07, 08:01 PM

Thanks for getting back to me. The dash never worked since I have had it (3 months now). The car still has the crossfire, no carb. The dash lights flickered for about 30 seconds once and only the lights in the cluster flickered. There was no information (speedo, tach, etc.). this led me to believe it was the grouding problem, so that led me to tearing it apart today and finding only 1 harness. The car runs verry well for the brief times I start it. So I am assuming the computer is still working. I do have a real bad battery drain I have narrowed down to the LCD fuse in the fuse box. I was hoping that the ground fix would kill 2 birds with 1 stone. Any ideas anyone?

speedmaster4 · 03-18-07, 12:25 PM

upper connector has two rows of sixteen pins= 32 pins (not all are used and do not have wires to them); this connector is power, ground, cruise control functions, and sensor inputs to the dash display....lower connector has two rows of twelve pins = 24 pins (not all used); this connector selects signals from english/ metric switches and some other dash functions...haven't tried just unplugging the smaller connector as it is unused with my analog firebird gauges, but highly suspect that with no lower connector no display is commanded...if you indeed have no 24 pin connector (look down thru the top of the dash with the dash top pad removed and the connector may have fallen behind the radio) i can prolly look at my 86 wiring diag (dash displays 84-89 interchange so wiring 'should' be same) to tell you which pins from the lower 24 pin dash connector will need a jumper to command display in one (eng or metric) mode.

stick105 · 03-18-07, 07:56 PM

Thanks for the responses guys. I looked hi and low for this plug and still cannot find it. I don't know what to do now.

geekinavette · 03-18-07, 11:14 PM

Here's the diagrams for '84...if it helps:

more here if you need them: http://misterbill.homeip.net/Vette/wiring/

The "current leak" is in the trip odometer...which is powered by the LCD fuse. Mine does the same thing.

Bill

stick105 · 03-19-07, 08:19 AM

Wow this schmatic is awesome. Thank you!!! I will try a more detailed hunt for the harness this week. I can't believe the way people "rig" such a classic car. You would think if there was a problem they would of fixed it correctly, not alter it to make it a eazy cheap fix. I am angry not with the problem with my wire harness, but the idiot who messed with it in the first place. Sorry about the rambling, but some people shuold not have nice things.

Thanks again for the help!

stick105 · 03-25-07, 09:59 PM

Ok. I went to this place near my house http://corvettegeneration.com/ and the owner Wally was awesome. We went into the junk yard and looked at 5 or6 c4's and then I saw my missing harness. It came from the D.I.C. its the 24 pin connector. I bought one from him and went home to try it. I plugged it in and...NOTHING!!! I looked at mine (the one that I had originally) and noticed some intelligent being had removed the cover of the D.I.C. and wound the wire harness arround the swithches inside and replaced everything exacting. WHY!!! I plugged the original D.I.C. into the dash cluster and still NOTHING!!! I have checked all the grounds and am at witts end. I still have a battery drain on the LCD fuse and don't have any dash. Time to call experts. I just wanted to keep all up to date with my project.