Instrument cluster actuation test failure

[Karish]

Again I have the infamous "CCd" / "No bus" and every instrument is inoperative situation on my 2001 2500 with 223,500 miles. This has miraculously cleared before by cleaning and reseating every connection I can find and making sure every ground connection I can find is tight. This time, no luck. The truck still starts and runs, all the electrical accessories work, cruise control works even if I don't actually know how fast I'm going.

I ran the instrument cluster actuation test per the manual. I won the lottery with the codes; i got them all: 900, 920, 921, 940, 950, and, of course 999. The "wait to start" lamp did NOT light during the test. i know it works as it comes on when starting the truck. Manual says replace the instrument cluster (or CCA, or repair it) if the "wait to start" lamp does not light. Okay, so why am I writing this? Out of curiosity, has anyone ever experienced this? All the threads I've read about this issue, no one as ever mentioned the "wait to start" light failing to light and that was in fact the "smoking gun". And does anyone know what failure on the circuit board causes the light to not come on? Other than the engineer who designed it who doubtless is well retired by now.

 

[Topzide]

@Karish, I would suspect that you have a cold/broken solder joint on a ground trace on the board. This is all to common a problem with circuit boards that have age and vibration in there lives! I would examine it with a magnifier lamp and use a sharpie to mark things as you go. A DVM to check ground points back to connectors would be a plus! Short of having a full test bench to check every component, looking for bad solder joints is about the best you can hope for. Good luck with the venture into the unknown! I'm sure someone has more to add on their experience.

 

[Karish]

Topzide,

Thanks. I've heard of traces failing near the docking connectors. But I will make a more in depth examination of the CCA. A quick look didn't reveal any thing obvious. Something to do an the first sunny weekend above 70 F (or even 60 F for that matter) in the Interior of Alaska.

 

[petersonj]

Something to do an the first sunny weekend above 70 F (or even 60 F for that matter) in the Interior of Alaska.

Along with lots of mosquitos!

- John

 

[Karish]

Absolutely. Four mosquitoes will carry off a dog before a big mosquito finds out about.

 

[Karish]

I spent some of the magnificent weekend in the shop going over the instrument cluster CCA. visual inspections, continuity tests at rest and while applying some deflection to the CCA, found nothing wrong.

Let's assume the actuation test results ("Wait to Start" light fails to illuminate during the test) are telling me there is something wrong with the CCA and it needs to be replaced. Any ideas on where to get one? Not particularly eager to take my chances with eBay. Perhaps just a poor attitude on my part, but buying a used CCA sight unseen or tested seems dicey.

I appreciate the benefit of anyone's experience with this.