On the HUD issue. Can you see the display in the mirror? Do you see a blue glow in the HUD? If you do then you have the gears mis-aligned when you put it back together. The mirror can still move but not enough to reach the windshield. If you don't see any light then you have a power issue.

 

Do you have any HVAC blend door issues?

 

i judt checked and there is no display on the mirror. I do not see a blue glow either. Would the radio and HVAC module being removed cause any issues? Would be a bit surprised if it did, but they are out of the car currently. I can see and hear the mirror moving, does the mirror motor receive power separately than the light?

 

I do not, but some else had suggested to replace those while the dash is off. I did both the passenger and drivers side this past weekend. Thank you!

 

Did you make sure the gear on the mirror was aligned correctly ? On the small plastic black piece there is an arrow. With the motor set all the way back (pin near the windshield) be sure that you see about 5 teeth showing. That should get you the proper alignment.

 

Thank you sir, I'll realign it this weekend as I pretty much just guessed based on where the teeth were worn. I was not aware of the alignment marks.

I'll try it again after aligning, but there was no light anywhere in the unit, so I think I still have another issue.

On another note, I am working to replace the lights in the HVAC unit. I have LEDs but I am now thinking I may need resisters as well. LED's are DigiKey part number LTH3MM12VFR4400-ND
I used these same LED's in several of the gauge cluster lights, I'm worried I might need resiters there as well. Not sure there's space to but resisters on either location, might have to go back to incandescent.

 

For those wondering, polarity on the HVAC unit is below.
Black sharpie line is negative side, its pretty easy to see which solder joints are fresh/non-factory.

 

Polarity for the radio bulbs, negative side marked with black line.

 

No problem, yes you do need resistors. There are some YT videos telling you which ones you need. I am going to do that myself, but I really don't feel like it at the moment. I just put everything back together. I replaced all my LED's and the boots for the ebrake and shifter.

 

The instrument cluster doesn't need resistors (I don't think)

 

By the way.... I forgot to mention BE SURE that you have the brightness turned up on the HUD button cluster. I had an old man moment and mine was turned all the way down.

 

I did not need resistors, the LEDs I bought must have had them built it. The OEM LEDs in the radio immediately burnt out with a 9V, while the ones I bought were fine.

I did try fiddling with the HUD controls. Mine has never worked, so that was one of the first things I checked. I have now replaced the mirror pin, aligned the gears, soldered the brightness photoresistor leads together, and still have no display. I'm not really sure what to try next, I don't have a very good understanding of how the display actually works. The pictures below are taken with the ignition on, car off, and display all the way up.




I am in pretty good shape, only a couple more things left:

Fix HUD, may end up leaving it nonfunctional

Fix dash peeling back from HUD bezel

Shifter allignment(?) There is an aftermarket short shifter so i cannot use the neutrel control pin to realign everything, not sire if there is another way?

 

You are going to have to trace it back to see if you can find the issue. There are 2 wires on that white set of pins, that connect to the IPC (instrument panel cluster). These directly connect to the main logic device of the HUD (that blueish thing). I am not sure which pins it is, but it's either the last two on the right or left. You can use a multimeter to see if you are getting power there. The ignition needs to be on. The far-most left or the far-most right is the ground. The inner one is the power from the ignition. See if you are getting anything there. Keep in mind this control is seperate from the gear moving switch. So even though the gear moves the HUD may not turn on. Also disconnect the light sensor as well.

 

I would test the HUD switch as well. See if you are getting voltage there. If you aren't on that dimmer it could be that the dimmer is just in a "no brightness" state all of the time. :-)

B

 

My buddy did all the lights in my 99 back in the day, everything on the inside. He used the same led for everything and it was perfect. He also sanded the tips of the leds flat which dissipates the light and reduced the potency of the light in your eyes without ruining the uniformity. Blue leds in a black interior looked great, I got more compliments on the lighting than anything else on the car.

Also, I had to do a vent door the next year, should have done it then but I didn't have any codes for them at the time. Vent doors suck. Car should look great wen your done!

 

I'll check both sides of the plug for 12V, thank you sir. Would power come from the same pins as the mirror motor? That portion is working. I'll also check the dimmer itself, I'm assuming this is essentially a potentiometer? I'll see if I can find some pin diagrams/information online.
If the HUD is getting power, would the next step be to replace the whole HUD, or are just the projector part? Parts seem to be few and far between. There are lots of used HUDs around $200.00. At that point, I may just leave the HUD non-functional.


It looks like I will be spending the $80.00 on the oversize HUD bezel, despite my efforts to avoid this. The dashboard vinyl has shrunk and cannot be slid back under the bezel, and trying to push anything underneath to fill the gap seems a bit cheesy to me.

The shifter seems to feel a bit better after being regreased (at least with the car off), so I am going to skip realigning it.
When the weather is nicer and I can bring her to a lift, I may try and change out transmission and differential fluid as she does have ~120k miles.

 

I would have liked to use the same LED's for everything but I ended up having to use two different types as the smaller 'sockets' in the instrument cluster only accept T5 (PC74) bulbs.
(1) T5 / 74 / PC74 Twist Socket Bulbs. I got these one Amazon from "Wow LED Just Here"... We'll see how long they last. I would have liked to get something more reliable, but there were very few options. These are the brighter of the two.
(2) Digikey Part Number LTH3MM12VFR4400-ND. I have much more faith in these bulbs, and used them in the radio, HVAC unit, window switches, trunk/fog light switch, HUD adjustment switches, and for the larger 'sockets' in the instrument cluster. They were relatively easy to mount into the 'sockets' and had to be soldered onto the HVAC and radio boards.

Sanding the tips is a good idea, if they're too bright I may do that while things are still mostly apart. I used all white LED's, but blue would have looked great as well. It definitely looks much better than before, I can't wait to see it once the dash it all back together!

Some other folks had suggested the blend door actuators, so both of those are replaced.

When everything is all set, I'm going to add a list here of all the things I did (and could have but didn't) for folks in the future. I might make a separate post as a guide with information about replacing all the bulbs with LED's. There is lots of good information out there, but very scattered. I'd like to compile all the bulb types, polarities, locations, etc. so it's all there for others who are replacing their dash lights.

 

I was going to check the HUD pins for 12V, but was unable to find my multimeter, or even a 12V bulb... I'll borrow one from work and reply this weekend.

In the meantime, I am having trouble finding an oversize HUD bezel. I bought one from Top Flight Automotive, but it was the same size as the original. The only ones I can find that are specifically "oversize" are ~$200.00. At that point, I'd probably spend $100 more and just buy a whole dashboard.

Anyone have any luck with other brands at a better price point, or making their own? The curvature of the dash would likely make this difficult.

 

Corvette Central has HUD bezels by year so size should be right based on year your C5 was built. Not sure of prices though.

 

Thank you Skooter, I should have added some context in that I need a bezel that is oversize to cover up the shrinking vinyl on the dashboard, not to replace my existing bezel. I could be wrong, but I believe all C5s have the same size HUD Bezel and even the same HUD.
My existing bezel is actually in really good shape, but the vinyl has shrunk quite a bit over her 25 years. There is no way it's stretching back underneath the bezel. Picture is attached.

Since the dash is already off of the car, replacing the whole bezel would not be much more work than gluing an overlay on top. I would consider 3D printing something, but I am almost certain it is too large for any 3D printer I have access to. Taking measurements to get the slope/curve right would also be a huge pain (and likely involve some trail and error). The 3D print texture/look would stick out like a sore thumb too.