Speed pulse sensor? Reverse light wire?
 

The new head unit I'm installing needs to be connected to the speed pulse wire and the reverse light wire. It's a nav system and the input from each will help the system determine where the car is more accurately (in case you were wondering).

So my questions are:

1. Where is the speed pulse wire?

2. How would I run the reverse light wire to the back bulbs? My main concern is how to get it through the engine compartment.

Any pictures would be GREATLY appreciated.

2002 Boxster S.

Thanks!!

The speed wire is located in the radio harness and the reverse wire is under the drivers seat. You don't have to fish a wire back to the back up lights. I have the exact info at home, but I'm at work right now. If you got to Rennlist.org and do a search, there are threads that will direct you to what you need to know to hook up your navigation system.

The speed wire is in the harness. Now, for the reverse issue: Unless you are actually installing a backup camera, what most shops do is forget about the reverse wire, and twist the e-brake wires together, so that the Nav unit thinks it always has the e-brake on. The advantage here is that now you (or for legal advice, your passenger ;) ) can operate the Nav while the car is in motion, otherwise you'll have to pull over anytime you want to put in an address, etc. Like most things in this country, the switch is there for liability.

Drop me a PM if you need detail specifics on any of this.

Patrick

Thumper: Cool, that's great information. Toolpants just linked me to the Rentech thread with the reverse wire, so all I need is a good photo of where on the harness the speed pulse wire is..... wait a second. I pulled out my stereo and looked at the drawing on the top. It says wire A1 is the "speed volume." Is that what I'm looking for? Will that work?

bmwm750: Thanks for the advice. The manual says the reverse wire is for the Nav system. It needs both the reverse and speed wires connected so it can tell if the speed it is sensing is the car going forward or backward. Otherwise the positioning isn't as accurate. I was told that I can hook the wire to a toggle switch and that will bypass the system. Is this correct?

Toolpant: Thank you very much. I'm quite relieved to see that the reverse wire is so easy to get to. One question: How do I remove my seat?

The install is finished. Thanks for the help, it was quite valuable.

1. The speed pulse wire is A1 on the OEM harness.

2. The reverse wire is the blue and black one underneath the driver's seat.

3. It is very important that the headunit sends a signal to the amp to turn on. I missed that last step and Ray helped me out. The wire for that one is the only wire on the yellow section of the OEM harness.

I'll get some pictures of the Nav unit today.

Glad that worked out for you. Lets see some pics now!

Patrick