2000 XK8 98k miles. Jag dealer said ohms reading too low for A2 and A3 cylinders and recommended replacing wiring harness at a cost of $5k- I can’t do that. Got a “looks good” engine harness off eBay but can’t figure out how to get main connector unplugged from the firewall. Other wise I think I can do the rest. Any help/advise please

 

That does seem to be an extreme course of action and a very large labour element as a new harness from JLR is $1340. As I write there have been 130 Views but 0 Replies to your question which gives some indication of how rare it is to replace an engine bay harness on the XK8.

What set of symptoms, DTC's and testing led them to this conclusion?

Graham

 

It's pretty rear to do this. The difficulty depends on which harness you're replacing. Both are a pain in the neck. The main harness is slightly easier except to disconnect the connector down by the AC compressor. There is a large multi plug on the firewall.

If you're replacing the ECU harness, you'll have more difficulty. Unplugging everything from the ECU and transmission controller is not difficult, but removing the harness from the right rear engine compartment is tough. Then, the harness runs along the firewall in a plastic conduit which has to be opened to remove the harness. The worse part is on the left rear of the engine compartment where the harness feeds behind the heater hoses to the rear left compartment which holds the brake and power steering components. You also have to get under the car to remove the transmission connector which is part of this harness.

Removal of the throttle body, wipers, cowl and a few other items allow more space to work. Let me know if you need any more info.

 

Thanks for the replies. The harness I’m trying to replace goes to coils, injectors and about a dozen other places. From mostly the top engine area, it goes down behind the throttle body and secured to the firewall somehow. This big pin connector is my hang up. It has a bolt hole on inside and a bolt on the opposite side of maybe another connector fastened together with the one I need off. Can’t see - only feeling blindly by hand now. Maybe I can stick my phone down there and get a pic. Dealer said ohms reading was too low on one of the wires at both A2 and A3 coils and harness needed replacement.

 

The bolt at the back of the connector uncouples it. There's a pull tab on the other connector next to the main one. It just unplugs. The main connector slides into a metal frame attached to the firewall. Pull straight up and it should disconnect from the holder.

 

The most difficult connector will likely be the CKPS. The harness has plastic 'fir-tree' block mounts to keep it close to the engine behind the compressor and PAS pipes.

The right side of the engine is easier. (Alt.,Oil temp and Oil press switch) Everything else is near the top.

Ohms too low on A2 and A3? Is that with coils connected or open circuit?? (does not make sense)