Well, here I am with my Vatte all pulled apart and my new HUD doesn't work. I decided to test it before I reinstalled everything. Hooked up all the wires and fired her up and nada ! Checked electrical connections and they seem fine. Dashboard lights seem to adjust fine and the adjustable mirror in the HUD is working but I get no light from the HUD. This would lead me to think that the HUD switch and wiring are OK but the HUD bulb is bad. Is there a projector bulb in it? Can't seem to find any way of replacing.

Any suggestions????

I got the HUD new Fred Beans. Hope they stand behind it if the HUD is bad!

 

do you have the HUD projector sitting in the dash where it will be mounted?

sitting in the drivers seat, you don't see anything on the windshield?

please be more specific as to how you are "testing" the HUD.

 

Yes, I am sitting in the drivers seat. There isn't any light coming from the hud. When I get out of the car and look into the projector I can see the mirror moving when I use the HUD switch. Doesn't seem to be any light coming from it.

 

The HUD is installed in the dash.

 

Some obvious questions, but gotta ask . Are you using a new 11 wire harness from the switch to the HUD, and is the HUD wire plugged into the top of the dash?

 

Yes to both. I checked the continuity of the 11 pin connector and it is good. I am feeling real down now.

 

you checked continuity, did you check signal? Do we know what kind of signal should be sent to the HUD unit? Battery voltage? It's really very simple. If you are getting the proper signal for HUD illumination and CAN signal for readout then you simply need a new unit. That's all.

 

I hope to check these, but I don't kow which pins on the HUD switch and instrument cluster are for the light. If I knew which ones I could check for voltage and resistance. Does anyone which pins are for the light?

 

Have you made sure that the illumination/brightness is turned up on the projector?

When moving the control switch for up/down, you mentioned the mirror moves...did you watch the windshield the whole time looking for an image? If you're tall, try sitting lower in the seat and doing this as it only adjusts so high.

Where did you get the 11pin wire? Is it an original?

I've done tons of these installs and have never had a dead projector, so it's quite unlikely (though always a possibility).

You might recheck your connection to the top of the instrument cluster as well...make sure it is tight and secure. If using the homemade connector from Josh Lawson, you'll also want to make sure that you have the connector into the cluster going the right direction since he doesn't use the correct white plug for the cluster (from the HUD control switch).

 

Yes, I did test the illumination/brightness and turned it up all the way. I looked into the projector from outside the car to see the mirror move. I got the harness from Josh Lawson.

I checked and rechecked and rechecked my connections. There is absolutely NO light coming from the projector. I also connected it up while it was removed to look into it and NO light at all. I checked the pins on the cluster and HUD switch and they are fine. It is curious that the mirror moves but no light.

I am obviously a little down about this because my Vette is in a million pieces!! Can't go back because my dash now has the HUD cutout.

I could check the HUD switch, cluster and HUD voltage/resistance if I had a wiring diagram. Anyone have one?

 

Does the 11pin harness have a black connector on each side?

My best guess is that the harness is wired incorrectly and not making proper connections to the instrument cluster.

 

Yes, it does have a black connector on each end. I have sent Josh an email asking about the wire routing. I checked the continuity and it seems fine.

Any other suggestions? Again, a wiring diagram would be helpful.

 

The first HUD that I got did not work. It was for a coupe and I was installing it in a 01 Z06 which were different part number but I assumed that they would interchange (I still don't know that answer for sure). Figured the only thing that was different was the redline mark. You have to have the 11 pin cable to supply the dimmer control for the HUD before it will light up, that would be the first thing to check. You should have a varying voltage going into the HUD when you move the dimmer slider on the HUD control. If your height motor is working then the cable is at least installed correctly. Check your pinout using the diagram (photo) I posted back in Jan which can be found by clicking HERE. The last 4 wires (purple wire end) in the white plug is the new wires, be sure they are wired like in the photos.

 

SpeedyZ - Thanks for the wiring diagram. I will check this out tonight. I have the 11 pin harness.

Do you know which pin(s) on the instrument cluster/HUD connection (not the switch connection) are for the HUD lamp? If I new this I could measure for voltage. Any other suggestions for checking the voltage? Do you know which pin(s) on the switch are for the HUD light intensity? If I knew this I could check the switch.

Also, what didn't work with your first HUD? I have a coupe so maybe they sent me the Z06 HUD.

 

My first HUD did the exact same thing yours is doing. Motor control was fine but no display what so ever. My second HUD, also used, was from a Z06 and it worked fine. Again, I assume they should be interchangeable but I have not found anyone that could tell me for sure.

I don't know which pins is which, I documented all this stuff very well (just about everything but the protocol) when I did mine but have not seen my papers since! Even the GM service manual does not provide the pinout of these connectors, they show the lines, just not where they are in the plugs. It should be easy to find with a voltmeter. There is an extra 4 wires which is purple, light blue, orange, and gray. The will be motor up, motor down, page, and the dimmer control, but not in that order. The ground is one of the existing 7 wires. For some reason the purple wire is sticking in my mind as the dimmer control, but it has been over a year since I was in there. Since your motor works those two will be easy to find. Just probe the wire in the plug and check the voltage, then press all the buttons and slide the dimmer control. You will quickly find which wire is which. I would first probe on the switch end of the 11 pin cable. Be sure you leave the cable connect while testing, I would use a straight pin or small wire (straightened paper clip) and slide it down in beside the wire into the back of the connector. Be sure you find a good ground for your voltmeter, not always easy on a plastic car! Once you find which wire is which, then check the other end of the cable the same way and make sure your getting the same results. If all is good then try probing the connector on the top of the cluster going to the HUD, you should find these exact same 4 wires and signals. These 4 wires only pass through the cluster to the cable going to the HUD. The cluster does not alter or use these signals, just passes them on to the HUD. From memory the wires from the cluster to the HUD will be power (+12VDC), ground, motor up, motor down, page, dimmer control, data in, data out, and data clock (again, not in that order). there may be two power and two ground wires through that harness, can't remember for sure.

There is no so called "HUD lamp" signal. There is no lamps in the HUD that light like the rest of the dash light do. The HUD uses a VFD (Vacuum Florescent Display) which creates it's own light by hitting phosphor with electrons. And pretty dang hard I might add, the display itself has a heat sink on the back of it! They do this with pulses at a rate of several hundred times per second, they vary the pulse width to make the display brighter or dimmer. On it's dimmest setting these displays are pulsed at an extremely low width (very short pulse), something very low in the nano seconds or micro seconds. On it's brightest setting the pulses are still in only in the micro seconds. Again, I had this stuff documented and had all the exact timing specs but it vanished. So what I'm saying is there is no signal that causes the display to light like there is a other parts of the dash, there is a signal (0-5VDC I think) that is used by the controller in the HUD to vary the pulse width on the display making it brighter or dimmer. So there is no signal you can simply apply voltage on that will light the display. Hope that made since?

 

Speedyz, you are a wealth of information! Thanks for your help. Since your original HUD did the same thing as mine I plan on checking the part number first and then the diagnostics that you suggested.

 

this might help if anyone didnt post this already...

http://forums.corvetteforum.com/show...3&forum_id=103

theres a guy posting pics on c5 general of his hud install... pm him for help

gotta love these forums~!