Installing a HUD - questions about wiring, etc...

[redimpulse]

Hey all, how goes it?

 

Most of you have no clue who I am, as I've been lurking for quite a while. I've a 2001 Impala LS and I've been wanting to install a HUD for quite some time. A friend over at NAIOA and I had been working on it for a while, but we found that the HUD out of a 97+ GP wouldn't work, as it got its info from data sources not available in the Impala. So my question to you guys is this: I've seen that a bunch of pre-97 W-bodies have HUDs (I didn't know this). What data sources do these older HUDs use for information? What kind of wiring is needed to install a HUD?

[94CutlassSLCoupe]

I don't see why the speed, high beam indicators, and turn signal part wouldn't work in an impala with one from a GP.

 

The HUD works as follows:

 

Speed-reads off the feed for the speedometer needle. 40,000 pulses per mile

Turn Signals & High Beams - works off the feeds for the light in your dash.

 

Since that is all a 1st GEN w-body really has in its HUD except the check gauges or low fuel lights (depending on year)...I see no reason why you couldn't use the easier to find 97+ GP HUD.

 

Overall, you need a little skill to wire these bad boys in, but honestly the hardest part is modifying the dashboard. I put one in my CS that was FOR a CS and it still wasn't really fun.

[GnatGoSplat]

Strange. A 97+ GP HUD I would have thought would work best.

The 88-96 HUDs use the same signals as the 97+ GP HUD, that is primarily discrete inputs for the turn signals, and 4000-pulses per mile for the speedometer.

 

A 97+ HUD only differs in that it has an additional serial data connection for the radio display. You don't have to hook that up.

 

If an 01 Impala lacks the 4000-ppm, then you may need to use an 04+ GP HUD which is completely Class 2 bus driven.

[GnatGoSplat]

Ok, I think I'm seeing why you think a 97+ HUD won't work...

 

From the 01 Impala service manual:

Speedometer

The IPC displays the vehicle speed as determined by the IPC. The IPC calculates the mileage based on the class 2 vehicle speed message from the PCM. The IPC calculates vehicle speed based on the class 2 wheel speed message from the EBCM if a loss of communication or malfunction occurs with the PCM. The speedometer defaults to 0 km/h (0 mph) if the IPC detects a loss of class 2 communications with both the PCM and the EBCM.

 

However, I dug around a bit, on Connector C1 of your PCM, pin 55, there is a DK-GRN wire coming out which should be a legacy VSS (4000ppm) signal. That's the same wire color as the older cars used. I bet you can use that to drive a 97-03 HUD (or older one if you prefer). I don't know if anything inside the dash uses that to make it easier to find that wire, but I'm sure something does. I can research this more for you tomorrow if you'd like.

[redimpulse]

Hmm. Great thoughts everyone! On the '04+ hud; we were going to go that direction, but they are hard to find and expensive. And on the '97-'03, the issue was the mix of class 2 and analog (I think) data; had us confused and worried about frying something. But I'll look into the PCM wire that you mentioned, see if that works.

 

I have yet to pick up an HUD, as I wasn't sure if it'd be able to connect properly. Didn't want to be left with something I modified and would have to try and unload on someone else, y'know? But I can get a '99 HUD from my bud in Jersey; starting to think it may be a good start.

 

Any other ideas, one way or the other?

[no1kicker]

I would check out regalgs.org, I saw a few people put GP HUD's in their Regals. Might be helpful.

[GnatGoSplat]

Hmm. Great thoughts everyone! On the '04+ hud; we were going to go that direction, but they are hard to find and expensive. And on the '97-'03, the issue was the mix of class 2 and analog (I think) data; had us confused and worried about frying something. But I'll look into the PCM wire that you mentioned, see if that works.

 

You don't need to hook up the Class 2 on a 97-03 HUD at all unless you have a factory radio, it's only for the radio station display.

I'd say finding that VSS wire is your best bet. I don't know how universal the Class 2 bus data is, so if it changes between years or models, the 04+ HUD might not work.

 

[redimpulse]

Well this is what I found over the past couple days. The major issue between the GP and the Imp/Regal is the Class 2. No one can figure out how to wire it properly. I checked out the RegalGS guys, and most of the HUD threads have been lost so I can't find much. But it does seem that they got it to work mostly; but the Regal shares a lot more wiring with the GP than the Impala does.

 

The main reason we were thinking possibly the 04+ is because it doesn't use Class 2 at all.

[brianteel]

the impala and monte carlo use the class 2 data signal to power the dash. they do not have the VSS signal going inside the car. the 04 GP uses the can system which is even more different. you will need to run a wire form the PCM to the HUD.

[redimpulse]

I didn't know that the 04 GP uses CAN! Well I guess that opens up a whole new CAN of worms, doesn't it? May be easier to hack the Class 2 data...