Hi Everyone,

My 97 XJ8 4.0 is driving me insane, albeit in a smooth powerful manner lol!

My Jag keeps blowing the ODB2 5amp fuse, I know I shouldn't but I tried a 7.5 and that blew also. I currently have no fuse in I think its LH heelboard fuse4.

Now some background, I had an issue with my cigar lighters, the rear one always worked ok but not the front cigar lighter. I took out the whole tunnel recently and fitted new bulbs and found a disconnected wire in the cubby hole, a white clip, I reinstalled the tunnel(the bit with the ashtrays etc) and lost the back bulb on the valet switch(don't you just love that). The cigar lighter in the front had started to work again but strangely enough it would light up with the headlamps off, and the rear one didn't, I then switch the main lights on the stalk and the front bulb goes out and the rear cigar lighter bulb comes on?????

Not sure if that may cause the odb fuse to constantly blow? Has anyone else experienced the odb port fuse blowing? before I go tracing the route I was hopeing maybe someone else has experienced anything similar.

My XJ8 has covered 134k on a nikasil engine, still going strong touchwood, i've a K&N air filter and aftermarket coils and getting 24.6mpg.

I've had to weld the drivers seat, do the timing chains and I fitted the metal thermostat tower, i've broken 3 of those plastic radiator hoses, and replaced all the ancilaries on the serpentine belt. Coming up i'm replacing the exhaust and manifold gaskets, that looks like fun, and the cruise control has never worked, just go straight into failsafe, although it continues to drive normally, I gave up on that. Well hope someone can help, take care all you Jag owners.
Cheers
Mick

 

The ODB port is on the same fuse as the cigar lighter is it not?

 

Hi,

I checked that and they have a seperate fuse, I have checked the wiring diagram and from the left heelboard fuse holder the cable routes down the lefthandside of car to the interior A post to a 20way yellow block, from there it goes into the centre console harness across to the obd2 connector pin 16.

Now that I know this I believe i'm going to find a short around the centre console, the wire should be brown\green\blue as the diagram said it was NGU, so today out with the stereo etc and see if I can find that short, i'm sure I heard some crackling back there the last time I had the stereo out, at the time I wasn't concerned as it stopped but maybe that was the fuse blowing, fingers crossed, i'll post up results later.

 

to make your cruise work, you need to either replace the brake switch, up and behind the pedal, or the two micro switches inside it, they can be had from radioshack for pennies. Hope that helps.

 

Hi,

Had the dash out yesterday couldn't find the short, but I did get the ODB working, it must be near the OBD port as it had been put in the holder the wrong way round, since Icorrected this the fuse has held.

Thanks for the update on the cruise, i'm on my 3rd brake switch, the one on it ended AA and I have tried a BB from the scrappers but that didn't fix it. I will buy a brand new one from Jag and try that, I think their about £60, anyhow thanks for your suggestion I had thought to try that to rule it out.

Cheers