Cell Phone and Radar Detector Power, Another Way

I was getting tired of plugging my cell phone charger into my cigar lighter, so I decided to permanently wire it into my car. I was thinking that I would use power from one of the various unused connectors or perhaps from the radio. But then I came across Vince’s article and it gave me the idea that I could use the BMW cell-phone connector.

What’s more important to note here is that I could use this connector for more than just a cell phone. I could use it for anything I wanted. Vince’s article details a way that you can order the connector and pins for the cell phone connector. In addition, both switched and unswitched power are available, and they are both regulated by individual fuses in the fuse box, so you can play around without the danger of seriously hurting the car. But best of all using this connector means no permanent wiring changes to the car. I would not have to cut a single wire that was part of the car, which sounded pretty good to me!

First thing I did was prepare the charger. I opened it up, and replaced the metal contacts on the circuit board that ran to the tip and the sides of the cigar lighter with wires about 1 foot long. Then I closed the charger back up, running those wires out the hole in the tip of the charger.

Next I prepared the radar detector by cutting the cord right before the cigar lighter plug. I placed the radar detector where it was supposed to be on the windshield, then ran the wire along the inside of the window and down the seam of the door, and under the steering column. From there, if you lift the cover on the shifter and the handbrake, you should be able to fish the wires through to where the cell phone connector is. NOTE: Those that are truly anal-retentive will probably want to run the wire INSIDE the plastic pieces along the inside of the windshield. Other articles here can tell you how to remove it.

I then found the cell phone connector as detailed in Vince’s article. I took the wires from the charger and the radar detector and started soldering the pins on them. One wire from the radar detector (the positive lead) goes to a pin. One wire from the charger goes to a pin (once again, the positive lead). The remaining wires (which should both be ground [negative lead]) should go together into one pin.

Now put the charger inside the center console, with the piece that connects to the cell phone (and the coiled cord with it) coming out from under the bottom of the console on the passenger side behind the seats. I used a piece of Velcro (the non-fuzzy side) to hold the cell phone connector against the back wall.

Time to start the final piece. Put the pin for the radar detector into the hole in the connector for switched power, and put the pin for the cell phone charger into the unswitched power hole. Put the shared pin into the hole for the ground connection. Plug the connector into the cell phone connector in the car and you’re ready to go!

NOTE: I also replaced the fuses in the fuse box that related to the cell phone power with 5 amp fuses (smaller than the standard fuses). This just gives me an extra degree of protection that I like. I would have used smaller fuses (like 1 or 2 amps), but I couldn’t find any in that form-factor that had such a small rating.

Digital Temperature Gauge

In my old 1.9 Z3, I had the on-board computer which told all sorts of interesting things such as estimated range, average speed, and outside temperature. Call me strange, but with my new M roadster I miss that. I miss the 400 mile trips during winter in the dead of night with the top down, watching the temperature fall to below freezing, with the reassurance that yes, I was out of my mind.

On the Euro-spec M roadsters, they get an outside temperature gauge. According to rumor, it doesn’t work that well. Besides, to add that to my US-spec M roadster would cost more than $200, which I don’t have. I finally found a digital temperature gauge that met most of my needs, RadioShack part number 63-1023. They offer 2 different temperature gauges for cars, this is the better one (and more expensive, about $20).

The good things about this gauge are that it displays both the inside and outside temperature at the same time, it records the highest and lowest temperature, and it has a nice electro-luminescent backlight. On the down side, the LCD is hard to see from some angles, the backlight only stays on for 3 seconds when the button is pressed, and it uses batteries instead of car power. But altogether, it’s the best one I’ve seen anywhere.

The first thing I did was add a black sticker to the front that covers up the “RadioShack” name. It’s a small thing, but call me anal-retentive. Next, I went out and bought a radar detector windshield mount. I decided the best place for me to put the gauge was above the rear-view mirror, on the driver’s side. I had to be careful about the angle I placed the gauge at, since from some angles it’s hard to see. Once I had the angle figured out, I had to cut the detector mount down to the right size.

Next, it’s time to do something destructive. Cut the lead for the external probe halfway between the display unit and the probe itself. You will need to attach some extra wire to make things work. The place I placed the probe was up in the front bumper, behind where the front license plate goes. I took the black mounting bracket that comes with the gauge, removed the rubber piece, and superglued the mounting bracket in place. Next, I connected some more wire to the probe piece and ran them into the passenger compartment.

In the cockpit on the passenger side, underneath the glove compartment there is a piece of plastic held in place by 3 plastic screws. Remove this piece of plastic by turning the screws a half turn and removing them, then the plastic piece slides out. You should be able to see a rubber grommet by the speaker grill.

On the inside of the engine compartment you should be able to see the other side of it. Run the wires for the temperature probe through this hole, you should be able to push the rubber grommet aside enough to get the wires through. I then attached one side of a plastic 2-lead connector to the wires I ran through the hole. Don’t forget to use lots of nylon wire wraps to hold things in place in the engine compartment.

You can see (kind of) how I ran the wires along the passenger side of the engine compartment. Now it’s time to remove the plastic covering the inside of the pillars. To remove the side coverings, simply “pop” them off. I would recommend using a screwdriver with the tip covered by a towel (to prevent marring the surface) and wedge it in the top, then pull down. These should come off with a nice “pop”. You need to do both sides. Next, you need to remove the top frame covering. The clear plastic around the dome light gets scratched very easily, so please be careful (it’s white plastic under the paint, so it really shows when it’s marked up. The clear plastic pops off, try prying from the drivers side – that side is supposed to come off first. Then remove the light bulb assembly, it also pops out. Once again, be careful not to mark up the paint. Next, remove both visors, you will need a torx screwdriver. Then remove the one remaining torx screw that holds the top piece in place, it’s behind where the light assembly was. Last, just pull up to remove the covering.

Now it’s time to start placing things where they go. Use some superglue to attach the gauge to the radar mount, and be sure to let it dry thoroughly. Place it on the windshield in the proper location, and run the wires where they would need to go (you will have to attach more wire, the gauge only comes with 10 feet of wire and much more than that is needed. You will be running it along the top of the pillar and down the sides, next to the glove compartment. Once down there, attach the other end of the nylon 2-lead connector.

Now, just plug the connector in, replace the plastic piece below the glove compartment and put the molding back in place along the pillar and you are all set! Not quite as good as a factory installation but it does the job.

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Chrome Lighted Shift Knob

Since you can never have enough chrome in an M Roadster (open to debate, perhaps) I decided to add the BMW chrome gearshift knob. However, if I did that I would loose that cool lighting effect from the stock gearshift knob. I decided to try and make a chrome lighted gearshift knob.

You will need to remove the standard shift knob. Lift the cover up around it (it’s just held in place by small tabs on the side), and find the connectors for the wires leading to the knob. Disconnect these and simply pull straight up on the knob. It’s tight, but it should come off. Be careful not to hit yourself while pulling it up.

The first thing I did was to take apart the stock knob to see how it worked. It’s really just 3 tiny LEDS and a resistor under a knob emblem that let’s light shine through. Since BMW does not sell this emblem as a separate piece, you will need the one from the stock knob. Put your fingernail under the edge and simply pry up. It’s held on by double-sticky tape and should come off easily. Be careful not to scratch either side. Also important, the “silver” look of the numbers is not really paint. It’s some sort of dust that very easily wipes off. Do not get your finger anywhere near it, or you’ve just ruined the emblem.

The next thing you will need is the wire connector off the standard gearshift knob. Cut the wires (but leave some space to work with). I choose to get some nylon connectors from a local electronics store and solder it on the end of the BMW connector. That way I can still take my knob off without dealing with the BMW connector (which is a little big and won’t come off though the hole in the cover that easily).

Now it’s time to work on the chrome knob (which you need to purchase, of course). You need to get the emblem off without scratching the knob itself. The knob itself is covered in some sort of thin film that protects the metal (which is very soft). If you scratch the knob, it will look BAD. So don’t do that *smile*. The emblem is held on by the same double-sticky tape, but lots more or it. The best way I found is to use a dremel and drill directly into the center of the emblem with the dremel screw-like attachment, then yank the emblem off. Remove the remaining double-sticky tape, but save it – you will need it later.

Under the emblem you will find a little hole which is almost the right size. If you were to put the M emblem over this hole, the “R” and the “5” would not light up, because the hole isn’t big enough. Carefully grind the edges away where those two spaces would be (i.e. instead of a round hole, you would create a hole that looked like it had mickey-mouse ears). You don’t need to go very deep, long enough so that light can shine through. Now look at the underside of the knob. Inside you will see a couple horizontal plastic bars that hold the knob in place and keep it from spinning around. Through the center of the knob (in the hole on the top) drill out a vertical line that intersects the horizontal bar. Go all the way through till it’s completely open. You are almost done at this point.

Go back to your car. Figure out where that horizontal bar would go (it’s plainly obvious). Now cut (grind, actually) a small groove down one side of the stick. It doesn’t need to be very big, but you need something to run the wires in. On the stock knob, the wires actually run along the outside of the knob, but with the chrome knob we can’t do that so we need this grove. It won’t affect the functionality at all, there’s still PLENTY of metal left. When I did this, I took a vacuum and left it up close to where I was grinding to keep all the particles from spraying through the inside of my car.

Back to the chrome knob. Take some very small gauge wire (I used the individual strands of a telephone wire) cut two 18″ pieces. One one side, solder an LED to it. I used a jumbo orange LED from radio shack, their part number is 276-206 and the color matches the rest of the car pretty well. On the other end of one of the wires solder a 470 ohm resistor. Then solder on the mating end of the connector that you soldered on the BMW connector.

Go back to the car. Thread the connector attached to the knob through the leather shifter cover, and place the cover back on the car. Now carefully place the chrome knob on the car. Line up the wires in the groove you cut and on the top have the wires come out next to the horizontal bar (i.e. the LED [attached to the wires] still isn’t in it’s final position, it’s sticking out further). If you did everything right, the knob should be in position and on tightly, but if you hold both ends of the wires you can gently slide the LED back and forth. Pull on the wires until the LED is flush in the hole.

Lastly, you need to put a diffuser and the emblem back on. For a diffuser, you can use the white plastic one from the stock shifter, or simply cut a piece of white paper in the appropriate size. Use that double sticky tape you saved earlier to put the emblem back on. Re-connect the wires and put the leather cover back in place, and you are all set!

Another thing to watch out for is to test-fit the emblem into the chrome knob. I’ve had two different knobs, in one the M emblem fit just fine, but in the other I had to slightly grind the emblem down to get it to fit. Also, be careful not to push too hard getting the emblem in place, it CAN crack internally and have ugly white lines running through it. In direct sunlight, the knob can get VERY hot – so you may want a pair of driving gloves. And the wires you use to connect the LED can get damaged very easy, so if you take the knob off again you may want to plan to replace those wires.

All in all, I’m happy with my unique shift knob!

Dual-Stage Radar Sensor

I started with the excellent article on adding a motion sensor to the BMW alarm. I encourage everyone to read that article first, as I’m not going into enough detail to do the whole job. Consider this as a set of “release notes”. Also, I assume both the BMW alarm and the motion sensor have been installed at this point. Read over all of this first, since I make comments like “connect with to power” then later talk about “put a switch in”. It’s better to do this all at once, but easier to explain using several passes at it. Remember: measure twice, cut once, measure again.

Changes desired from the existing article:

I wanted to use a dual-stage sensor, thus the car would “chirp” when someone got too close to it, before setting the alarm off

I wanted to know which stage sensor had been set-off, by visual inspection (i.e. LED)

I wanted a cutoff switch for both the motion sensor, and the outer stage “chirp”

I wanted to have the sensor be easy(er) to adjust [i.e. not have to pull the car apart to adjust the sensitivity]

I purchased a dual-stage sensor from www.autotoys.com. This sensor is basically the same as the one mentioned in the previous article except that it has two stages of detection and comes with a small piezo buzzer to use as the outside “chirp” sound.

The first thing I did was to decide how I was going to wire everything and and measure everything. Based on other articles and talking with various people, I decided to put the sensor in the center dash, between the seats (under the cassette storage area). After removing the cassette storage bin, I was able to use my pocket knife to lengthen the hole already there to be just long enough to slip the sensor in. I put velcro tape on the sensor and the underside of the dash, and attached the sensor there. This had the advantage of making the screw to adjust the sensitivity easily accessible. I just remove the cassette bin (no tools needed), then use a small screwdriver to adjust the sensitivity. Thus, desire #4 was satisfied.

Next, I wanted an LED to show the status of the sensor. The sensor has an LED already attached to it, a bicolor red/green LED. I simply desodder it, sodder in extension wires, and added the LED to the end of those wires. I was able to snake that new cable (I used heat-shrink tubing to hold the wires together) through the gear-shift area (the shift boot cover comes off easy) and into the blank punch-out button area (which the light for the alarm itself and the glass-breakage sensor already were). I drilled another hole, and used one of the radio-shack LED black plastic covers to give it a professional look. It’s a little crowded there, but still looks good. OK, desire #2 is done.

I needed a place to put the buzzer that was going to serve as my outside warning. I decided it needed to go in the engine compartment, since that was the place the siren was, etc. It’s small so it can go anywhere. I choose up by the drivers wheel, inside the engine compartment. I tie-strapped it into place.

Now I had to find a way to get a couple wires into the interior of the car. If you look where the battery used to go in the ’96 model Z3, in the M roadster there is what looks like a bunch of cables doing just that, but they are fully covered and have a rubber grommet around them. I was able to move the rubber grommet just enough to snake the cables through to the interior. They come out just above the kick-panel speaker in the passenger wheel-well.

OK, this part is from memory (so PLEASE test all your connections before listening to me). I believe I hooked the red wire on the buzzer to the unswitched power supplied to the alarm. The black wire (ground) from the buzzer was attached to the green trigger wire on the motion sensor. I believe when motion is detected, this wire to connected to ground, thus the buzzer goes off.

Now I wanted to install cutoff switches, so I needed a good hidden location. I found one beneath the glove compartment. There is a piece of plastic that goes out from the firewall at a 90 degree angle, that’s what I used. It’s the piece of plastic that has the 2 or 3 plastic turn-screws to keep it on. In the center I was able to cut the holes for the switches themselves. I picked up a couple neat-looking blue auto-switches from a local electronics place and test-fitted them there. Make sure when the switches are in the plastic that there will be enough space to put the piece back on. Some of the tolerances were pretty tight. Now, cut the wire that supplies power to the motion sensor and connect one side to one terminal on one of the switches and the other side of the wire to one of the other terminals. Do the same thing for the cutoff for the “chirping” buzzer. OK, item #3 on my list is done.

OK, one last problem. When the car is running, so was the motion sensor. This has two side effects: the green light keeps going off indicating movement and the outside buzzer is also going off! While driving! This was unacceptable to me.

The solution was to use a relay, like is often used for fog lights and such. Make sure you get a real relay that has both an “87” and “87a” connector (the first one I bought said it had both, but really only had two “87” connections). Basically, you hook power up to the relay and based on whether power is applied to a third connector (or not), passes or does not pass power. The difference between “87” and “87a” is that they are the inverse of each other (one has power when the other doesn’t, and vice-versa).

I don’t remember the details (I’m a computer guy, not an EE), but it should be easy to understand based on the diagrams with the relay. Basically, hook ground an unswitch power directly to the relay. Then the terminal that determines whether power should run or not is hooked to the car’s “switched” power (the violet wire with a white stripe in the alarm harness). Then the terminal that has power with the terminal just mentioned does not have power should be feeding power to the motion sensor. Now, the motion sensor (and the outside buzzer) are only on when the car is switched off!

That’s it!

If you have any questions, you can email me at caslis@netcom.com