My auxillary fan doesn't come on when I turn the air conditioner on and the temp gets above N when idling for 20-30 minutes. Where do I begin?

 

According to the diagrams there's no tie-in between the compressor and the aux fan on your model.

In the engine bay there's a fuse box and relay panel on the left side (there's one on the right, too, but we want the left side)

Check the #4 fuse in the fuse panel. If blown, replace it. Should be 30amp

If the fuse is OK find the temp switch in the water pump houisng. Remove the wires and touch them together. If the fan now operates the switch is no good.

If the fan doesn't operate.......

Find the cooling fan relay near the left fuse box. It'll have brown/green, black/green, and green/brown wires. Unplug the relay. With the relay unplugged you'll see the wiring terminals in the plastic relay socket. Using a small jumper wire you want to jump the black/green wire to either of the brown/green wires. If the fan now operates you have a bad relay. If it doesn't operate then the fan motor is faulty, or the wiring between the relay and the fan is faulty, or the ground is faulty.

Cheers
DD

 

While I'm waiting on my distrib cap gasket to arrive I figured I would tackle the aux fan problem I'm having. Above Doug says to check the temp switch I should remove the wires and touch them together. The wires are within two "connectors." Do I just pull the wires out of the connectors to perform the check? Thanks for any help in advance and for forgiving my ignorance.

 

Use a short piece of wire to stick into the connectors to "jump" them together. Or a heavy guage paperclip.

When you get a bit more involved with repairs (or now, if you want!) you'll want to make up a selection of "jumper wires" with different clips, terminals, and probes on the ends. Very helpful.

In this case, for example, you'd probably want a piece of wire with a .common 250" male spade/blade terminal on each end.

Cheers
DD

 

Thanks again Doug, but you are speaking a different language. Is this something I could go to my local autoparts store and buy? Aside from damaging the care with my stupidity, I'd rather not electrocute myself.

 

Never mind. I figured it out. I'm an idiot. And it was the switch. The fan worked fine when I connected the wires. I'm going to replace the switch, but am also considering buying the dual electric fan system. Anyone have any experience with buying and installing these?

 

In the manual's instructions on replacing the thrermostat switch, it says to drain the coolant. Is this necessary? Also, is the switch (part #eac 2510) jaguar specific. I can't find it for sale (online) anywhere in the U.S.?

 

Just Google the part number. Lots of vendors have it, such as:
FAN SWITCH | Part EAC2510 | Jaguar Parts & Land Rover Parts

Yes, you need to drain the coolant to at least below the level of the switch...or work really, really fast to reinstall the new switch while the coolant is gushing out of the hole.

Then you'll need to bleed the system. Search for postings in the archives on this or post back.

Cheers
DD

 

Radio Shack and others have test/jumper elads like these with alligator clips that will work in many situations

Hobby Engineering: Test Leads and Jumpers Category

There will be other times, though, where you'll want different clips/terminals on the wires depending on what it is you're jumping

You won't electrocute yourself

Cheers
DD

 

Are you sure EAC2510 is the correct part number?

Cheers
DD

 

It's hard for me to read the manual sometimes, but it is either 2510 or 2310 (it says this is the number for the 6.0). The one at jagbits.com is $50, which seems expensive. Surely there is a non-jag part that is compatible.

 

I'm not aware of a non-Jag substitute, personally. There might be, though. Others will chime in.

Motorcars LTD webpage says that's the correct number as well but the way they have it listed was a little confusing to me. My fault.

Cheers
DD

 

Yeah, I saw that. Said it was only compatible through 1993, if I'm remembering correctly. Oh well, I'll spend some time searching and see if I can't come up with an alternative. If not, I'll go ahead and get the jag switch. I HAVE to get back on the road. Seeing the car in the drive and not being able to drive it is almost depressing. Doug, what are your thoughts on replacing the switch alleviating my problem (temp gauge getting slightly above N in stop and go traffic and aux fan not engaging)? In Kirby's book, late model XJS owners report gauge readings in this range. I'm starting to think that I might be over reacting a bit, but my OCD compels me to err on the side of caution, especially with overheating situations.

 

With the fan fixed the temp will likely stop rising in stop-go traffic. If it doesn't more investigation might be called for.

A little above the "N", in and of itself, isn't anything to worry too much about. BUT...this is MAY. If it goes a little above the N now, what will happen in August?

It's also possible that the gauge isn't 100% accurate...not uheard of.

Anyhow, fix the aux fan and go from there.

Cheers
DD

 

When I did that on my Mercedes, I didn't drain the coolant. When you unscrew the cooling fan temp switch (engine not running), there is a little bit coolant coming out but I think that's ok. Actually, some Mercedes owners use the temp switch hole for bleeding the cooling system.

 

My aux fan is not working too. I spent an afternoon following Doug's instructions and check the temp switch, relay, fuse and they all work fine. I tested the aux fan itself with a 12v supply and it runs. So, the only areas will be the wiring from relay to the fan or ground. I have a hard time to believe the wire is bad because the wiring harness is wrapped tightly.

How do I test the ground?

Thanks.

 

THanks for joining in the discussion. This seems to be a common problem How did you check the switch? My fuse is fine and I can make the fan spin by jumping the connectors that plug into the switch (which would suggest the switch is bad). How do you check the relay? Thanks.

 

Wiring faults within a wrapped bundle are rare unless the bundle is rubbing against a sharp edge or such.

Much more common are *connection* faults at the grounds or at the terminals inside the plastic connectors.

I don't know where the ground points are for the switch or the fan motor itself so you may have to actually trace the wiring bundles. On my older XJS, FWIW, the grounds for these items where at the ends of the metal panel that runs across the top of the radiator.

Cheers
DD

 

When you "jump" the wires at the switch you are simulating a closed switch...as it would be when the engine gets hot.

This in turn "gorunds" the control side of the relay, energizing the relay and sending voltage to the cooling fan...which is grounding on its own.

So...your relay is good.

But, since you asked, to here's how I would test the fan relay:

Check that the two brown/green wires at the relay have 12v at all times. If they don't, you have a blown fuse, a wiring problem, or no voltage supply TO the fuse.

Jump the wires together at the temp switch and use a test light or meter on the green/brown wire. It should be grounded. If not you have a wiring or connector problem.

With voltage at the relay (brown/green wires) and the relay grounded (green/brown wire) the relay should energize with a click and send voltage to the black/green wire. Use a light or meter to check for voltage.

Hope this helps

DD

 

Doug, considering the foregoing, would you suggest some way of testing the wires that "connect" to the the switch? Or whould you do any further examination to try to more pinpoin tht situation? Personally, I'd hate to buy a scarely expensive switch. Any idea about where I can get more detianeld instruction son bleeding the collant when repalcing thn=e