hey guys i already posted this once but in the wrong area any help would help. I recently got a 2000 jaguar xj8 and it has some weird wiring and i already fixed one that was to the alternator for no reason, but i have no idea what this plug is and need help to know what it is and what it powers (pointing to part in picture)

 

Don't know, but the two hard plastic lines off the coolant reservoir are reversed.

 

I saved the shop foreman's butt back in the late 1990s when he finished working on a customer XJ8 and left for the day.

Customer picked up the car but came back 20 minutes later with coolant pouring all over the ground and the low coolant light on.

Service writer asked if I would look at it before I went home.

Pressure tested the system and finally figured out that those lines were swapped. (common error early on in those days)

I swapped the lines and topped up the system, sent the customer on his way.

They just did not 'look-right' being crossed I guess.

 

Your model year has the wiring guide below

Close to your year there are some changes to the wiring guide so you have to be careful and reference the correct one

Can you tell the wire colors ?

jagrepair.com/images/AutoRepairPhotos/jagxj2000.pdf

 

 

My coolant lines were crossed when I bought the car. Made no difference either way.

 

That plug you’re pointing to looks like it’s going to a replacement later model (X350 04’+) heater coolant pump. If the heater works, I’d say leave it alone unless you’re ocd like a lot of us here and just want the correct heater pump.



Whenever I see writing like that, I automatically suspect a used engine unless someone got just the valve covers. Anyways, check to see if the tensioners have been done.

 

that is not an EV1 connector that the x350 uses

 

To remove and switch the coolant lines, slide two tiny screwdrivers between the plastic that looks like you would squeeze to expand. (Warning: if you squeeze you’ll break them.) Search for posts with pics if confused.

 

Question: intake runners look gray. I’ve only seen black before.

 

As pcolapacker states, those connectors become very brittle after all this time so care has to be taken when disconnecting them.

Jaguar makes a special tool, but I've never been able to find one.


A home-made tool using the flattened ends of thick electrical wire works pretty good.

Or a pair of small screwdrivers can also be successful, although you usually need three hands with this method!

..

 

You cannot pressurize the atmospheric catchment tank. (coolant overflow)

The reservoir has ports above and below the 'cap' for pressure and for overflow/suction return.

THEY DO MATTER.

 

old and faded

 

Where did I say it didn't matter? Maybe I should clarify. I didn't have coolant blowing all over the place or anything catastrphic like that because my expansion tank was empty as it usually is.

 

Xalty, I said it “looks like”, I didn’t say “it was”. I’m just trying to help members out.


Sun bleached

 

Looks like the connector to the coolant bypass pump (as someone else has mentioned). The pump is used to bypass the rad and help get heat faster on cold days.

It's a brushed motor, so often a problem with age and the brushes wear out. Worth checking operation while you are going through things, When mine acted up I was able to make new brushes I got from a small engine repair shop - getting pretty hard to find those these days.