How-To: Install a VDO Gauge In Your Air Vent

[G. P. Burdell]

I am not the first person to do this. Bimmerforums member lkstaack posted his writeup before:

http://forums.bimmerforums.com/forum...ad.php?t=83387

The method I used to install my water temperature gauge differs in two ways: (1) it renders the driver's side vent nonfunctional, to protect the gauge contacts, and (2) it does not require you to cut the completed assembly open to change out the light bulb.

Parts and tools required:
Dremel tool with cutting wheel and sanding drum
Crimping/wire stripping tools
VDO 2-1/16" gauge of your choosing (Note: I have not handled Auto Meter gauges, but if they are of similar dimensions to the VDO gauges, they should work too.)
Spare driver's side vent (BMW part number 64 22 1 387 061; verify with dealer)
Wire
Ring terminals
1/4" spade connectors
Tap-in connectors
Screwdrivers
Ratchet and 10mm socket
22mm socket, 22mm wrench, or adjustable wrench
Satin black spray paint and rubbing alcohol (if needed)
Tape
Epoxy
Silicone sealant
Eye protection

Disclaimer:
The procedure described herein is based solely on my personal experience. I am not an automotive professional, nor am I affiliated with BMW. I am not responsible for any damage or injury you incur while following this procedure. Work at your own risk. Verify part numbers before purchasing. Use appropriate safety equipment while working with power tools.

Procedure:
1. Close the vent flap at the rear of the vent and sever the linkage to the thumb wheel. Silicone the flap shut at the back. This is so that moist air from the vents will not cause condensation on the gauge contacts.

2. Cut all of the vent louvers out. Leave the topmost movable horizontal slat intact. Cut the other horizontal slats at the middle and save them.

3. Mark holes resembling those shown in Picture 1. The hole in the top will allow the gauge to fit all the way into the vent and allow access to the gauge light bulb; the hole at the bottom will be for running the wires. The vent plastic is thick enough that these holes will not compromise the structure. Cut out the holes with the Dremel and the cutting wheel. Wear eye protection.

4. Fit the gauge into the vent. Make sure you have enough access to run wires to the gauge contacts, and to remove and replace the light bulb. Trim as needed to get the fit you want. It will take a few tries to get it right. Use the Dremel and the sanding drum to shape the bottom of the topmost movable slat so that it fits around the top of the gauge. See Picture 2.

5. Once you're satisfied with the fit of the gauge, take it out, mask off the face and contacts, clean the barrel with rubbing alcohol, and apply 2-3 thin coats of a quality satin black paint. This assumes that your gauge has a white plastic barrel, as mine did.

6. It is possible to connect the wires to the gauge after the gauge has been epoxied into the vent, but it's easier just to wire things up beforehand so you don’t have to work in such a small space. Make the appropriate wiring connections with plenty of wire to spare, along with 1/4" spade connectors or whatever your gauge requires. Feed the wire ends into the vent and down through the bottom hole.

7. Scuff up the paint where you will epoxy the gauge into the vent and fit the gauge into place. Mix the epoxy together and apply it to these points. A small syringe helps to get the epoxy into the space at the bottom of the gauge.

8. Carefully cut portions of the horizontal slats (which you saved in Step 2) and epoxy them into place around the gauge. The top right slat may require a bit of contouring to make it look good. See Picture 2.

9. Transplant your stock headlight and fog light switches to the new vent. The headlight knob pulls straight out; wrap the knob in tape and grab it with a pair of pliers. Undo the 22mm plastic nut and remove the switch barrel. The fog light switch pops out from the back. Installation into the new vent is the reverse of removal. I've always wanted to say that.

10. Now that you've finished installing the gauge into the vent, it’s time to install it into the car. Remove the driver's side lower dash panel (3 Phillips head screws) and the knee bolster (3 10mm bolts, plus 2 Phillips head screws for the OBDII socket, if you have one). If necessary, on the passenger side, remove the glovebox and the lower panel holding the footwell light.

11. A convenient spot for gauge ground is on the left side of the dash. Two M6-threaded studs are available. One of the two on my car was occupied with other grounds, so I unscrewed the painted nut to connect the grounds to the other one. See Picture 3.

12. Run the signal wire(s) from your sender into the cabin. On the passenger side, there is a passthrough just above the edge of the carpet where a bunch of other wires enter the cabin. On the driver's side, there is one just below the brake booster. This passthrough may appear as an oval-shaped hole behind the clutch pedal. See Picture 4.

13. For wiring gauge power and lighting, consult the gauge manufacturer's instructions and Ron Stygar's writeup (http://www.unofficialbmw.com/e36/int...do_gauges.html). I do not have the HK stereo option, so I took gauge power from the glovebox light instead of from the HK HiFi switch as Ron did.

14. Install the wired gauge and vent into the dash. Test the lighting and gauge function, then put everything back together.

[G. P. Burdell]

The next two pictures show the finished product. It looks good. The red bulb cover doesn't match the amber stock lighting, but it's close enough.

[themadhatter]

thanks for the write up!

[Daved]

Good write-up but I'd do it a little different, I'd put a some panel in front of the vents so the only thing you could see is the gauge and no holes would be surrounding it.

[G. P. Burdell]

That was actually my original idea, Daved. I bought an 8"x10" sheet of ABS plastic from the local hobby shop, but then I decided that replacing the slats would balance out the slats in the center vent on the other side of the instrument cluster.

Also, the ABS panel insert would have to be curved. Fitting the gauge into that insert, then, would require more than just a circular hole. It would require careful Dremeling and some patience.

If I were building a race car and already had a panel of gauges in the center vent, then a panel in the driver's side vent would be just perfect.

Thanks for the compliments!

[beatniks325]

thanks for the write-up, I was following your progress in the other thread....

looks cool!!!!

[Hornswoggler]

wow, nice work!

Great write-up!

[Beamin']

I would like to do that for oil temp or oil pressure... has any one done that?

[Beamin']

Disclaimer:
The procedure described herein is based solely on my personal experience. I am not an automotive professional, nor am I affiliated with BMW. I am not responsible for any damage or injury you incur while following this procedure. Work at your own risk. Verify part numbers before purchasing. Use appropriate safety equipment while working with power tools.

[.

Isn’t it bullshit how you have to put a disclaimer in a forum DIY so you don't get sued/blamed because some idiot fucked up their car by being careless and stupid? Soon you will have to sign a waiver and get it notarized just to view bf.c!

[G. P. Burdell]

I would like to do that for oil temp or oil pressure... has any one done that?

lkstaack installed an oil pressure gauge. Click the link in the first post in this thread. It should be just as easy as wiring up the water temp gauge, except you're installing an oil pressure sender and running the signal wire(s) from the engine bay to the cabin.

Thanks for everyone's compliments.

Also, some data:

While the car is warming up, the VDO gauge reads 160 deg. F when the stock gauge first hits 12 o'clock.

After engine has reached operating temperature, VDO gauge reading ranges between 185 and 195 deg. F. Stop-and-go traffic does not have a significant effect on the water temperature. Ambient temperatures range from 25 to 55 degrees F.

This is for an M52 engine that's unmodified except for the Conforti CAI kit.

Now I'm tempted to add oil pressure/temperature gauges, but I don't know where I'd put them.

[joe325i]

Isn’t it bullshit how you have to put a disclaimer in a forum DIY so you don't get sued/blamed because some idiot fucked up their car by being careless and stupid? Soon you will have to sign a waiver and get it notarized just to view bf.c!

LOL
its funny because its true..
Accually No... I really hope that dosnt happen... I ALWAYS laugh how people do stupid things and are like.. Oh well the directions didnt warn me about that... Oh this country makes me sad sometimes... I guess common sense isnt as common as everyone things.. *sigh*


Nice write up though

And saying installation is revurse of removal is just damn cool to say

[Robstah]

very nice. hopefully you can show it off at a meet in the near future. im still waiting to fully finish my interior and exterior before i start strutin my stuff at any meet.