Well other than checking for power or ground at each of the splice packs with the combs removed during the time all of this is happening there is no more I can help you with that…you should always trust your equipment so maybe get yourself a new DVOM…the leads are usually the first things to fail….maybe find a scope in your area that can put a scope on your car.

 

I am very thankful for all your help. I will keep posting here if anyone else have any idea and as a journal for myself, to keep track of things done. Today I got different readings again and I think I did everything right and that DVOM was ok. Pin 2 was 9,25≈. On splice packs everywhere nothing except bottom pack with 4 wires, black/white wire was 1,8-2,6.



I put combs back on and went to change battery. Unfortunately even though battery was reading good voltage, car was unable to start on it and the car itself was reading almost 1,6v lower than was my measurement on the battery outside of it. So I put back the old one and noticed, that the car is again reading lower voltage than was my reading of it outside of the car. But it started ok as usually, I left car idling for a while and to my surprise no error appeard. So I turned on radio and still everything was ok ! Earlier using radio was 100% way to crash things. So then I used everything in the car I could (except tc switch, which never worked but thats another thread), every combination I could think of and still nothing, everything was working completly fine ! I dont understand why sometimes it is like everything is okay but most times it goes crazy. It could not be lose connectors on battery, they were tight before and this time I just put them on without tightening...
I will give it a proper ride later this week, but I am starting to thing that this car truly came alive and wants me to became insane because it isnt a first time something weird happened just to being somehow fixed by itself without doing anything... but I doubt that this time it will remain ok.

 

If you are reading 9.25 volts on pin 2 with BOTH splice packs REMOVED it seems like you have a short “to power” on pin 2…is this correct ??…if so a wire carrying 12 volts and the pin 2 wire are touching somewhere and causing this intermittent problem…you’ll have to inspect and “shake down” that purple wire from the DLC (pin 2) to each of the purple wires on the splice pack.

 

Sorry, it was measured with packs ON. But now I have found out interesting thing. First car start was fine, even with radio turned on. Then I turned it off and took combs off to remeasure things. Then I put combs on, started car again and error comes back again ! Nothing else was tampered with except those 2 packs.
So I let card idle and took off just one comb, from the bottom pack with less wires, which I also pictured post above and was showed in the video from you, C5 Diag. Wish I had done this earlier and not always remove both combs at once while car was off, because guess what, everything went back to normal, no extra dic error codes besides old ones, no abs/tcs warning light, gauges working, radio working and etc. ! (btw. DLC pin 2 was then remeasured for 0,5v.) Not sure if the pack is related to the anti theft system too, but my car doesnt care about it anyway, as showed in my video earlier.

Soo, if this isnt another stupid prank on me by the car. We might very well have suspects ? My wires colors doesnt match diagram seems like. But count and placement of them might be right when check againts that no start no crank video. So the suspects are Driver seat control module, Driver door control module, Passenger door control module and in instructional video it was Passenger seat module (but mine should be 2001 model and I dont see that module on 01 diagram) I think it might be the pin K, I have read small voltage on it before and during rain water often leaks arround side windows down to seats/carpet. So it might got also into where it definitely shouldnt be. Also I had problems with drivers lumbar year ago, I think I just pulled fuse for that. I will have to thoroughly test and check all of those things, because of colors not matching so rest might not be accurate too, but hopefully I might be finally close to solving this mystery.

 

Because everything pointed to pin K/driver seat control module, I pulled out fuse for it. After thorough testing it seems clear that wires to K or DSCM were culprint, because I do not experience failures of gauge cluster or radio anymore. I do not care about or need anything related to that control module, so it is "fixed" now and full fix is for some distant future.

 

Some electrical issues are because of the ignition switch, might be worth checking out.
Definitely NOT 100% that the ignition switch is the cause without first doing some testing. Here is a link to a thread about testing the ignition switch:

diagnosis

http://forums.corvetteforum.com/1568186703-post64.html


If the voltage measured at the fuses indicated in the link are more than about 0.2 or 0.3 volts less than the voltage measured across the battery posts using a digital multi meter then the ignition switch is the prime suspect. If the voltages are nearer the battery voltage then the problem is most likely due to poor grounds or corrosion on the star connectors in the passenger footwell: