Dashboard wiring harness

[athens7]

Does anyone have a schematic or similar diagram for the US Caterham under dash wiring harness? Specifically, I'm trying to find out what wires go to the OBD II port, and at which pins.

[Doug Liedblad]

This is what came with my car, build date Sept 2001.

It has the wiring harness for OBDII and worked when I was running the Contour Zetec engine with stock ECU (PCM)

Getting useful information from this was painful.

I also used the wiring diagrams from the build manual for some information.

There are some notes / added connections in red which may or may not be correct. Maybe useful is the wiring color code at the bottom left.

Doug

[athens7]

Thanks for the drawing, Doug. You're right, it's a bit challenging to read. My problem has to do with the OBD II port not properly communicating with my Diablosport Predator tuner. It turns out the Caterham harness was constructed with the third PCM wire attached to the wrong pin on the OBD II connector plug. A good look at the Ford factory wiring diagrams helped a lot. I would still like a good set of schematics if anyone has them. I have a feeling this won't be the last time I need to sort out an electrical issue (it's already the second one; the first was a dimming headlight, traced to a poorly connected wire inside the connector where the headlight harness meets the main harness inside the engine compartment).

[Doug Liedblad]

Now that you mention it I too used the Ford factory wiring schematic to track down problems. Or at leat try to.

Most of the issues I've had were poor connectors, the main one being where the green wire from the chassis wiring connected to the engine harness and then to the ECU. It turned out that the crimp on connector was installed over the insulation. Every now and then it would lose contact and stop working. Then start again anywhere from 30 seconds to 3 hours later.

Doug

[athens7]

It's nice to know there are still things in the world of which we can be certain: death, taxes, shite British electrical systems. Btw, I got a wiring diagram today from Cody at Caterham USA that was almost identical to Doug's, except it was labeled USA Zetec.

[Sean-og]

Curious how the title block of that drawing indicates it has been neither checked nor approved. :)

[moosetestbestanden]

Curious how the title block of that drawing indicates it has been neither checked nor approved. :)

Yes, well, speaking as one who's in the business of publishing drawings for building (something - anything) purposes I believe I can speak for those of us who have to make them. The contents of a drawing are *never* the responsibility of the maker. They are the responsibility of:

1: The client who makes ridiculous, impossible-to-achieve design changes at the 11th hour

and

2: The lame f*** boss who, usually w/ nose well and truly buried, agrees to implementing the changes even though he/she knows (somewhere in the dark recesses of his/her brown tinted oxygen starved mind) that they are impossible to achieve. Naturally, he won't get paid for the changes even though he/she secretly thinks he/she will.

So, those of us who make them never ever f***ing ever fill in those little "accountability boxes", or if we do it's w/ false information, like UFO or KMA:D

Edited to add gender neutrality. How PC :D

[slomove]

Chris, nice if you can get away with that.....As it happens we have had our friendly UL auditor for ISO9001 and ISO14000 crawling all over our place for the last three days. If this guy finds one of these accountability boxes empty or forged he can put us out of business (well, maybe not for a first offense).

At least he did not find that, just an abandoned box of unaccounted-for obsolete parts, an overflowing oil bin of our compressor, a blocked fire extinguisher in the machine shop and a quality control person using the stamp of another employee (the last one being really bad).

How annoying.....

Gert