The 25th mod, Parking Sensors (and how to fit them to a PT Cruiser without taking the bumper off)

Blimey, 25 mods...

Not that I do that much parallel parking but a useful modification none-the-less, costing only £20 quid and two hours work (which includes a cup of tea and a fag break half way through).

I bought this kit from a UK based eBay seller called TechSales-UK (aka Pull Up 2 The Bumper), they have all sorts of options from a simple stick-on two sensor version, right up to an eight sensor front and rear kit with a choice of LED or LCD screens. I'll be honest, it took bloody ages for the kit to arrive from them, 10 days in all, a bit too long for an eBay shop in my opinion. They're also a bit crap at replying to messages as I asked them no less than five times if the item had been dispatched before I got a reply. While the item itself is ok, it took forever to arrive, you have been warned...

So, onto the install. This is your guide on "How To Fit Parking Sensors On A PT Cruiser Without Removing The Rear Bumper".

The kit comes with everything you need to install (click on any picture to enlarge it), all you'll need are a few simple tools and a drill:






Four sensors for mounting in the back bumper:




The "wireless" LED display:




A power cable to connect to the reversing lights:




One control box into which all the wires go:




A 21mm hole cutter:




Four rings which are tapered on one side to allow angle adjustment of the sensors when fitted to a curved bumper:




Some really, really crap instructions and a sticky pad for mounting the control box:




The LED display also has a switch on the back to turn off just the beeping, leaving the display still turned on. Handy, as I'd imagine the beeping could get a bit annoying:




Before I attacked the car with a drill, I thought it wise to test the kit first to make sure it all worked ok. Running on Sods Law, if I spend half an hour testing the kit it'll work fine and in complete and utter Sods Law, if I didn't test the kit it wouldn't work!

Using a suitable 12v power supply (the old CB Radio power supply is still going strong, 15 years after I sold my last rig!), I headed to the work bench (ie. the dining table) and taped the four sensors to the edge of the table. I wired up the kit as per the crap instructions (honestly, the worst translation I've ever seen) and then wandered around the room making sure it could see me and that when it said an obstruction was on the left, that it was actually on the left:






So with the kit all tested, it was time to take a deep breath and get the cordless drill out...

Start off by removing bits of the car. Take out the reversing light, fog light and the offside rear light, then inside the boot remove the trim cover and take the jack out.

Next, place a length of masking tape over the back of the car like so (remember, click any photo to enlarge it):



Using a straight edge (I used a long upside down spirit level), draw a line across the middle of the bumper. Don't use the bubble on the spirit level because the chances of the surface your car is parked on being level are pretty much zero, so don't be misled. Draw a line across your tape, as per your long straight edge, wrapping the line around the bumper as you get to the ends.

Next, measure the gap between the number plate recess and the fog light and draw a vertical line straight upwards. Where your two lines cross is where you'll drill through. For the sensor on the far edge of the car, place your straight edge in the recess where the boot goes and draw a line straight down, again where your two lines cross is where you drill. Click on this picture to enlarge it and you'll get the idea:




Now for the really brave part, drilling the holes!

All being well, once you've drilled the holes, your back bumper will look something like this:




It's at this point I cocked things up for you reading this article as I got a bit carried away and forgot to take any more photos as I went on. Sorry!

I'll do my best to explain (in words only!) what you need to do next...

With your holes drilled, leave the tape on for now as it'll protect against scratches for what you're about to do next...

Behind the thin plastic bumper you've just drilled through is some thick foam, maybe 2" deep or so, behind the foam then is a rock solid metal plate. What you need to do now is create a path for the sensor wires to run through the hole you've drilled, through the foam and out through your fog light opening.

To do this, I got a sharp screwdriver and simply punched it through the hole I'd just drilled, aiming diagonally downwards (towards the middle of the fog light recess). Once the screwdriver was through, I made the hole in the foam a bit bigger by just hacking away at it with the same screwdriver. You need the path/hole through the foam to only be about 6mm in size as the plugs on the ends of the sensors are very small.

Alas no photos, but hopefully that makes sense, you need to make a hole through the foam, aiming diagonally down towards the middle of the fog light recess, keeping on your side of the massive steel plate. See now why I said leave the masking tape on your bumper?

Check your sensors, each one is labeled A, B, C or D. They need to run from left to right across your bumper so you're installing them in alphabetical order. Ok?

Once you've punched your pathway through, simply feed the end of the sensor wire in through the hole in the bumper, running it through your newly made path in the foam and pull it out through the fog light opening. The sensor then just snaps into place in the bumper. The end result will be two sensors fitted with both wires now exiting out through the fog light opening. Do this on both sides of the car so you now have all four sensors fitted with two wires coming out of each fog light recess.

Now for a slightly tricky part, you need to grab the two wires exiting from the reversing light recess, reach into the recess and put your hand through the metal plate and into the depths of the bumper. Once in there, feed the two wires over to the right hand side of the car. The aim of this being that you'll end up with no wires coming out of the left hand side reversing light recess and four wires coming out of the right hand side fog light recess. An assistant would come in handy at this point as they can reach in from the right hand side and feel for the wires you're passing through from the left.

Again, readers, I'm really sorry I didn't get any photos for these parts.

So, now you're left with four wires for your sensors coming out of the right hand side (offside) fog light hole and no wires coming out of the left hand side (nearside) reversing light hole. With me so far?

Now for another tricky part. Grab your four wires and again reach into the depths of the bumper, in past the solid metal at the back, so you're right inside the bumper with four wires in hand. Now feed these four wires out to the right hand side of the bumper. They will exit underneath the rear tail light you've already removed. Again an assistant would be handy at this point to grab the four wires and pull them up through the rear light recess. You should now be left with no wires at all coming out of the reversing and fog light openings and four wires now coming out of your rear tail light opening instead. Still with me??

There is a rubber grommet inside the tail light recess into which the wires from your tail light pass through and go into the jack storage area in your boot. Press the grommet into the car, from the outside. Once inside, snip a small hole in the grommet and feed your four sensor wires into the car. At this point you can now run your power cable through the same grommet. What you should be left with now is four sensor wires inside the car plus one power cable and then just the one power cable hanging out of your tail light recess. Squeeze the grommet back into place, it should fit snugly around the hole in the body work.

You haven't screwed any lights back in yet have you? If you have, take them out again!

You now need to connect the power cable to your reversing light wiring. This means you have to drop the power cable down through the tail light recess and aim it for the fog light recess. Once you have it in the fog light opening, you need to pass it through the back bumper again (behind the number plate area, where you ran the two farthest sensor wires) and it needs to exit where your reversing light is. Using a couple of scotch locks, connect the power cable to the wiring for your reversing light bulb. I've modified my rear lights so I can't tell you which wire is the positive feed on your car I'm afraid, perhaps someone who knows could post a comment at the end of this article?

So what you should be left with now is the four sensors fitted in place, the power wired up to the existing reversing light bulb, no wires hanging out of any recesses and five plugs in the boot of your car (four sensors, one power).

Still with me so far?

It was around this point that I remembered I had a camera and took some more pictures. Once again I'm really sorry about that, if ever I take my fog lights out again I'll be sure to snap loads of photos and post them up here.

Connect your five wires to the control box, ensuring the wire labeled A goes to port A on the control box, B to B, etc. As this kit was the "wireless" version, there is nothing else to plug into the control box. If you bought the "wired" version, you'd now plug your LED display in too. Attach the supplied sticky pad to the back of the control box and stick it as far up inside the jack recess as you can, so the jack doesn't interfere with your wiring. Use a few cable ties and tidy up your wires so they don't snag on anything. Still don't screw any of your lights back in yet, just in case something doesn't work!

A photo of the control box tucked far up inside the jack recess, nightmare trying to take this picture:




Time now for your tea break (and if you smoke, your fag break too).


Now all that remains is to wire up your LED (or LCD) display. The original plan was to sit the display on top of the rear view mirror but when placed up there, the mirror is a somewhat oval shape, meaning there were massive gaps on the bottom left and right of the LED display as the mirror curved away. So on to Plan B, sit the LED display on the top of the dash which would also mean a bit less fiddling about running wires through the head lining and down the pillar, etc:






You can of course place your display wherever you want and plug it into the fag lighter but I chose cut the plug off the end and wire my (fused!) display to an ignition live. The display doesn't turn on until you put the car in reverse so wiring it to an ignition live will be fine.

As mentioned above, the display comes to life as soon as you put the car in reverse and shows a digital read out of the distance to an object and also a little bar graph showing whether the obstruction is on the left or right hand side of the car:



To test the accuracy of the LED read out, I reversed up against the fence until the display read 0.5m and then I turned the engine off. I measured the gap between the back bumper and the fence to see how accurate the LED display is and I measured 0.45m (that's 45cms!) so the display is just 5cms out. Not bad for a £20 quid kit to be honest.

Some before and after photos. The sensors blend in really well and are barely noticeable:










So that's about it really. Quite a straight forward mod, just a couple of little fiddly bits.

Anyway, let me know your thoughts, questions and comments on this mod using the link below and if anyone knows which colour wire is the +12v live for the reversing lights, let us all know!


Modifications to date: Parrot CK3100 Bluetooth Hands Free Phone Kit, Debadged Tailgate, 'Semi-Stealth TomTom' Satellite Navigation, Chrome Wheels, Chrome Belt Line, Chrome Indicator Bulbs (Front), Chrome Fuel Door, Clear Side Repeaters, Chrome Indicator Bulbs (Sides), Altezza Rear Lights, Chrome Indicator Bulbs (Rear), Chrome Door Handle Recess Trims, Stealth iPod FM Transmitter, Mopar Front Fog Lights, 8 Ball Gear Knob, Port Holes, 8 Ball Door Lock Pins, 8 Ball Cigarette Lighter, 3rd Brake Light Decal, Sony Xplod Subwoofer, Altezza Fog Lights, Twin Fog & Reversing Lights, LED Fog Light Bulbs, Chrome Tailpipe Trim.