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DIY front LI (laser interceptor) install e39

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20K views 25 replies 10 participants last post by  Surge709  
#1 ·
Between this install and my orientation testing, I did a lot more thinking and planning, than actual doing. Knowing what I do now, I'd say this job would take approx 1.5h for a layman such as myself.

Special thanks to:
AMP, for helping me understand and execute wiring this unit.
DouglasABaker, for helping me find the easiest firewall breach.
Cliff, for answering every question you throw at him.

Items used:
- 18-22awg squeeze connector taps, from Radio Shack (check the plastic tunnels, some in my bag had shoddy quality control)
- 3/8" split flex tubing, from Lowe's
- 3M double sided exterior tape, from Lowe's
- multimeter
- electrical tape
- painters' tape
- household tools (phillips, flathead, pliers, 7mm socket, scissors, safety knife, file, flashlight, zip/twist ties)
- chopstick!

Installing the LI control unit:
I put mine under the center arm rest.
From the back seat...
1. Remove cubby under the rear ventilation. Pressure the vent slightly upward, and pull cubby out. Cubby is held in at the sides by plastic wedges.
2. Slide rear vent controls downward, to expose arm rest screws.
3. Undo two phillips screws and remove arm rest.
4. Back some of the tape windings off to create more working space with the 18-pin multicolored wire bundle (for a phone, which I don't have). Note: if you have the euro-style cubby arm rest, then this may create a predicament.
5. Using squeeze connectors, seat red power wire from LI with violet+white wire from car. Pinch with pliers. Do the same with black LI power wire and brown+black wire from car.
6. Using multimeter at the socket end of the LI power wire, test voltage with key in accessory position, vs key off. You're looking for ~12V and 0V, respectively. Skip this step at your own risk.
7. Confirm LI's heartbeat, with your wiring. Hook up the heads, turn key, switch LI on, listen for parking distance beeps and voice prompts. Find a TV remote that sets off a warning.
8. Wrap squeeze connectors in electrical tape to prevent re-opening.

From the front seat...
9. Remove the compartment to the passenger's side of the parking brake handle. It pulls straight out.
10. Invert the parking brake boot, so it faces to the sky. Push the highest edge of the boot towards the lowest edge.
11. Invert the shifter boot, so it faces to the sky. Push the passenger's edge of the boot towards the driver's edge. Tug out the large foam insulation block.
12. Uncover the center console side panel (approx where your right calf is with foot on gas). Remove one phillips screw, and slide panel towards trunk.
13. Uncover the lower dash panel (above the pedals). Remove 4 phillips screws, and one large black twist screw, which is at the back edge, between the brake and clutch pedals. I left this panel dangling down.

From the engine bay...
14. Remove the driver's microfilter. Use flathead to pry up the 3 clips on the center side. Pull out the lower retaining clip with both hands. Unclip the bar that holds down the microfilter lid. Remove lid. Pull housing out. This reveals the wiper motor compartment (above) and brake fluid compartment (below).
15. Locate the nickel-sized rubber grommet, just below and right of the wiper motor.

From the driver's footwell inside the car...
16. Lightly push out the grommet in 15 with a chopstick (or screwdriver). It's easy to find with a flashlight, and some sense of space.

From the engine bay...
17. Recover the grommet. Note: I had a friend watching the grommet as I pushed. If you don't, drop some tape on the outside so it can't escape.
18. Undo 3 phillips head expander screws from the hood insulation.

Installing the front head wires:
19. Protect the RJ45 connectors with painter's tape.
20. Create a lot of straight slack, to reach to the center arm rest.
21. Drop wires down through hole in 15.
22. Route wires through center console to arm rest. I used painter's tape + chopstick to do the fishing. You may need to use the 7mm socket to loosen one screw in the driver's side footwell, to achieve clearance.
23. Tuck wires under hood insulation, leave heads dangling by ~15in. I painter's taped my heads into place.
24. Bundle the "middle slack" of wires into the brake fluid compartment.
25. Using a safety knife and file, create grooves in 2 rubber parts (grommet 15 and U-shaped wedge) to tightly fit threaded LI wires.
26. Reseat grommet in 15 with chopstick.
27. Wrap engine-side of grommet-15 wires in electrical tape, with chopstick as a roller.
28. Cut split flex tubing conduit to fit between the grommets
29. Replace microfilter. Find the soft part of its ledge to let the LI head wires escape.
30. Cut split flex tubing conduit to fit between hood insulation and microfilter ledge.

Installing the front heads to kidney grilles:
This part was made much easier having the wood rig I built for orientation testing. That gave me a square reference for the plane facing front.
31. Wrap bottom bracket in electrical tape to avoid long term scuffing of kidney grille.
32. Test seat the heads to see where double sided tape strips should be spaced.
33. Lay 3 strips on the center-side fin, but leave the LI-side of tape still covered.
34. Use ruler to establish equidistance to rig.
35. Take advantage of the fin flexion by pressing LI head away from center. Yank tape cover off with pliers. Squeeze fins to seat tape.
36. Reconfirm distances to rig.

Put humpty dumpty back together again.

Micellany:
A. I'm using the factory volume setting from LI. It's plenty loud from under the arm rest. Cliff says I have 25% more volume available.
B. I thought about running the wires near the hood piston, dipping under the driver's wiper, instead of in front of the microfilter. I saw a two issues here. First, that compartment is a tight working space, so my excess wire bundle would have to go elsewhere (e.g. cabin or hood). Second, the movement of the wipers made me leery of having my LI wires frayed over time. That said, with good securing, this route is viable.




 
#4 ·
My install experience & some questions

I just put mine in this weekend (sorry no pics yet since my camera is doa). One question on the vertical v. horizontal mount: Has anybody seen any actual tests of the grill mount v. horizontal? I like the idea of putting them in the grill, but some of the guys on the radarbusters forum were saying the performance was worse. I'd love to see some side by side comparison before making a final determination.

In any event, I ended up mounting mine just below the bumper half way between the front plate and the headlights. Figured that would give the best chance of picking up shots at either the plate or headlight. A couple observations/tips:

Head mounting:
- I simply used the same double sided tape and the existing brackets (bent slightly to level the units) to attach to the bumper.
- Once everything was installed and wired up, used a couple screws to ensure it doesn't come loose.
- I bought some black allen head bolts for the front of the brackets since the silver ones that come w/ the unit stick out too much.

LI Wires:
- I used a fish wire to pull the LI wires up thru the mesh grill (use zip ties at top of grill to hold wires away from radiator and fan).
- Then just followed the hood release (again using zip ties to hide the wires) all the way into the driver's side footwell.
- There are 2 grommets to deal with. The first gets into the area under the hvac filter. It simply lifts out and you can slide the wires into the groove where the hood release cable goes.
- The second is a little more difficult, but I used the grommet where the hood release cable goes into the footwell. I pushed with a flat head screw driver from the engine side of the firewall and the grommet pushed into to footwell.
- Fed the LI wires thru on the outside of the gromment and then pushed the grommet back in place. I suppose you could use a dab of silicon to be safe, but I didn't because didn't seem it would be an issue.

Control unit & power:
- I removed the screwes from the front of the panel above driver's feet and pulled the front down.
- I mounted the CPU with velcro to the panel (figured it would be easier to remove if necessary and seems to work fine)
- I poped out the OBD plug (use a flathead screw driver to push in the tabs from the front - its kinda stubborn so take your time).
- Used the same type of splice clips to tap into the line. The green/white strip wire is positive, solid brown is ground. Double checked w/ multi meter to be safe.

Switch:
- I routed the wires along the panel to right side and for now its just kinda hanging there. Once I make some extension wires, I plan on mounting the switch in the ash tray.

Overall, not that difficult of a DIY.
 
#5 ·
Ignor my question, I'm "special"

Like an idiot I posted my question on the orientation of the heads before clicking on your like... doh. Anyway, thanks for the info - I think I may be moving mine to the grills too for the more stealthy effect.

Any worries on temps impact on the LI heads? They will be pretty close to the radiator there.
 
#6 ·
Like an idiot I posted my question on the orientation of the heads before clicking on your like... doh. Anyway, thanks for the info - I think I may be moving mine to the grills too for the more stealthy effect.

Any worries on temps impact on the LI heads? They will be pretty close to the radiator there.
They are well in front of the radiator - they'll be just fine...
 
#8 ·
2 questions: why are you mounting them horizontally instead of vertically in the grill? and have you considered mounting them behind the grill (but still horizontally)? You could set them into the grill a bit from behind without too much effort I would think.

Personally, I wouldn't mount them in front like that, but that's just me...

d-
 
#9 ·
It is hard to stomach the front of the car with the jammers horizontal. Reading on radardetector.net it seems the preferred installation is horizontal. I really can't make any conclusions until I do my own testing. I do however know I do not want a 900 foot punch through like chowdah got with vertical, bubbles up, so if I do go vertical it will be bubbles down.

Do you mean like this?
Image


I was considering this route but read the whole face of the jammer needs to be uncovered, not just the bubble.

Either way until I am able to test I do not want to mount them permanently so I guess they will stay zip tied here for now. I am hoping to do some testing with Cliff and will post the results here.
http://farm3.static.flickr.com/2687/4279380671_bd6e9629c7_b.jpg
 
#14 · (Edited)
I do however know I do not want a 900 foot punch through like chowdah got with vertical, bubbles up, so if I do go vertical it will be bubbles down.
Please read my orientation posts thoroughly, and carefully.

In short, I insinuate (and believe) that by not screwing down the head flat to the board, the head did not look straight ahead. That spells doom. It is also what you have in your pictures -- a "toe-out" appearance.

Think of a flat screen TV that faces straight ahead; i.e. not tilting left, right, up, or down. Imagine laying your LI head flush to that surface. Now spin the LI head like a pinwheel on that surface. Where you stop the pinwheel (i.e. where the bubbles end up) is the only "adjustable variable". That depends on what your car looks like, where you are mounting, and what you're trying to cover.

Actual testing supercedes theory. In the end, all that matters is whether your install meets your expectations.
 
#11 ·
Yes, that was what I was suggesting, but with the cutouts in the fins to bring the jammer closer to the front of the car. It is true that more than just the bubble needs to be visible, but it is not true that the entire face need be.

There are basically 2 diodes in each unit - a receiver and transmitter. The bubble covers the receiver. Located at the opposite end is the transmitter. Both need to be able to "see" forward, but the rest of the face need not - I would expect that slight shifting side to side during actual testing should allow you to determine the optimal position relative to the fins.

Haven't heard about Chowdah's experience...

d-
 
#16 ·
Chowdah, do you have a pic of the installed control unit of the Laser Interceptor in the console? I was going to have someone install it but I think I may do it my self with the help of your wiring info. Also, has the tape held up on the diodes inside the grills? I have not decided if I will put them in the grill or under the bumper sill.
Thx!
 
#18 ·
The second to the last pic that links to image shack? I see the control unit but it does not seem to fit well there. I wondered if you had any finished pics to see how u tucked the wires away and where u put the off/on switch. Others have put it in the glove box but I have not seen any good pics to visualize that. Thx for quick reply!!
 
#20 ·
chowdah, great tutorial, thanks for posting. I just got my LI and got most of the install done (only thing left is attaching the heads to the grill). just had 2 questions.

First, the wire that goes in front of the filter from under the hood insulation, how do you keep that from getting on top of the filter when you close the hood (for now i have to manually guide mine). Does it bend in the right position over time, or do you have to be careful closing the hood all the time?

Second, I have heard some concerns about the grill fins pointing slightly towards the center, resulting in a cross-eyed install of the sensors. Did you use any shims or anything like that to make sure they point straight ahead? Did you test the setup after the sensors were in place, or just when they were attached to the wood rig?

Thanks again for the great post!
 
#21 ·
Mine has naturally curled into the space above the strut, and to the rear of the oil filter & p/s fluid containers. I have never had to guide or mind it. The conduit had a natural shape that I must have utilized to my advantage.

I did controlled real world testing before (wood rig) and after. I did not use a separate shim, but the placement and sizing of the tape anchors helped me to attain proper alignment.
 
#22 ·
Yeah, I guess the sleeve you used for the wire might have had a natural curve. I'm sure mine will conform to the shape after a while.

So about the tape placement, how exacly did you place the tape? Both sides of the sensor, making it stick to both fins (center and headlight side) or just center? Multiple pieces or just one? I am also a little worried that the tape might not be enough to hold it in place at 1xx MPH. Did you have any other support in place? Sorry to pester you with so many questions, just trying to make sure I set it up in a correct and secure position.
 
#23 ·
Double-sided tape only on the center side of the head. 3 small pieces, ~1cm each.

I remember trapping each head with painters tape, as seen in the 4th to last picture. I remember protecting the LI's lower bracket with black electrical tape (step 31), and setting the back & bottom of the fin flush with the back of LI.

In step 32, I remember cutting small pieces, wedging them in various locations between the slats and the head, and checking the alignment to my rig.

With no other supports than 3 pieces of 3M tape, mine have not budged, in 4 seasons / 1 year.
 
#24 ·
Finished installing, hopefully it's aligned correctly. I guess I'll try to find someone with a gun to test it, or just wait until I run into a LEO. Thanks a lot for all your help, this install would have been a lot more difficult without your instructions.
 
#26 ·
Did anyone put in the rears yet? I am still torn as to what to mount them to?

Also, the fronts I mounted under the bumper in the BMW pre-designed ****s (kidding) for such an install. Will send pics later but so far they have been flawless (>10 hits with 0 pull overs). The brain and button I put in the driver's side storage compartment (only on the eurodash) but in the wife's car it went in the driver's foot well just in front of the pedals with two small holes drilled through the plastic (one for the button to work and the other for the speaker to send sound through). All in all, love this mod!