No codes from climate control panel,

Disconnecting the heater valve wiring has no effect

can’t tell by listening if the heater fluid motor is on or not. Does it run all the time, or only when the the climate control panel is active ? What is the best strategy for listening for an active pump ? Do I need to get under the car and place my hand on it to feel for vibration.-


Would like to pull the #1 relay and jump it as I’ve read others here on the forum have had troubleshooting luck doing that. Which terminals under the relay are used when jumping manually ?

Which terminals under the relay run direct to the motor (for checking the motor resistance). Have read on the forum the resistant should ve
a few ohms, Open resistance means the pump is shot, right ??

also the fuse associated with the heater pump, appears to be intact.

as nice as the heated seats are, but a little more heat would be swell in these 20 F days and night.


Z

 

Look at the circuit diagram on jagrepair .com for the terminals .
Read my post heater idiosyncracies

 

will give the diagram another go, but was
hoping a forum member could do the diagram
examination for me; my eyes are not what they used to be for that type of usage. Even reading glasses aren’t making up for the ravages of time.

On the good side, my distant vision is quite good. So my driving safety is not impacted.

thank you for the reply,

Z

 

The heater pump is between terminal 5 and earth on the relay in the under the hood fuse box .assuming fuse no15 is good ..or you could pull the fuse and go earth to each fuse connector with the ignition off ...if both show infinity the pump brushes are toast.
Or you can do it at the black connector on the baulkhead

 

Thanks for the information. Will get on it again when the temperature (and my back) show improvement.


Z

 

Key on, engine off, with the a/c panel on, the pump is running. Hood open in a quiet place, you should be able to hear it.

You can check the resistance of the pump at the relay. The terminals are labelled on the plastic tray where the relay plugs into. It is wired the normal way. Just lookup a normal 4 post relay for labels like 87 and 90. The pump is of course on the load side.

Best of luck, keep us posted.

 

at this point I’m going to put the car up on ramps and jack stands, wheels chocked and feel the heater pump for any sign of life, vibration, or noise.

As it is now I’m not sure what I’m hearing with key on / climate control on / motor off, as the intercooler pump is on and so is the CPU fan. Both contributing to the ambient noise factor.

All the resistance checks are pointing to the pump being MIA - DOA.

I’m inclined to try a used pump with a guarantee of sorts rather than try to rebuild the existing pump.

Z

 

TSB 303-11 was issued last in Sept 2001.

 

I can't remember how much access you have to the pump with everything in situ, either from above or below. It's pretty well tucked in.

If you do go the used replacement route, I'd seriously recommend cracking it open to inspect the brushes. It's not a job you want to do twice in quick succession, and a guarantee won't cover your time - or the cost of replenishing your swear box

 

I have done extensive work on my system including adding a second pump and I have never seen or touched the original pump ..I believe its behind the catalytic converter on the LHS. just take the cat off for access..ha ha ha

 

Can you go into any detail regarding the process of adding a second heater pump.

Z

 

I have written this up early 2021 but the crap search on this means I cannot find it.
Its a geological job so make sure the original pump is the problem.
Your system my have multiple problems. fan for the temp sensor not running/stuck water cut off solenoid /blocked matrix.
The pump is a Bosch 0392020039 which is a brush 12v pump. You must fit a 1N4001 (234or 5) diode across the brushes or you will bugger the ECU Band to positive
It fits with the motor upwards into the hose feeding the matrix. It goes on the inlet nearest the centre of the car .Tight fit but OK
Remove partially the expansion tank . Take off its mounting bracket and disgard it holds fine with the one screw.
The problem is the outlets are 19mm on the pump . Matches fine with the heater core also 19mm but the down section of the octopus is 16mm so you need a 19 to16 adaptor, hose clips and long screwdriver /flexible drive . Wire to the black connector.






Needs a respray..painted it black to disguise it,

 

That definitely gives you more workspace, lol, but it still comes out from the top.

 

on
JagRepair.com - Jaguar Repair Information Resource

it’s mentioned that the pump can come out from under the car:

”…..Once the hoses and plugs are removed you can drop the pump and valve out the bottom……”


I haven’t tried it either way yet, so not speaking from experience. But any way that lets me keep the throttle body in place seems like it might have some benefits.

Z

 

thank you for posting / re-posting the steps you took !

Z

 

I missed that how-to sadly

If that works best for you, then it's surely the way to go. I think the cat is easier to remove on the AJ27s since the connection to the centre box is a bolted flange rather than slide-on and clamp. I went from the top and took the whole lot out as I was replacing all the hoses. As Gus says - they can be tight!

Either way, some have had issues with the lower 'instrumounts' twisting off, so an advance shot of PB-Blaster or the like won't do any harm. Having the cat off certainly helps access to those two mountings.

 

Here’s hoping the corrosion on the left hand CAT fasteners won’t turn out to be a buzz-kill. Getting those to break free without “BREAKING” is going to be a good test for my favorite product “Freeze-Off”



Z

PS is it “normal” for there to be no 12v power to the #15 fuse without the engine running and the climate control panel turned on ? I’ve checked every possible combination of switches on & off, including the ignition key turned to the “on” position and engine not running.

But without the engine running there is no power to the #15 fuse circuit which powers the heater pump. Just seems odd that it’s not powered up with the key “on” and engine off ?

 

Yes, if the coolant temp. is <16° C:- see the attached JTIS snippet. Check also that F3 (5A) in the engine compartment fusebox is intact.

 

I had checked all the under hood fuses, but re-checked #3 just in case. Still good.

good information about the coolant temperature. However, unfortunately, it doesn’t answer any of my questions. When I was circuit checking the coolant temperature was over 170 F / (77 C more or less) .

My next step is to try another heater coolant pump. It will be a while before I source it and get it installed. But will report back when there is something to report.

Z

 

I was jjoking when I said take off the cat its far easier just to add a pump.

Now listen up.
If you study the diagram of the heater pump and its relay you will see that the fuse comes after the relay contacts so unless the relay is switched ON you will have zero volts at the fuse . The relay terminal 3 gets its live from supply 4 ( a single number means always live) The relay coil from 40 ( two numbers means ignition switched.)
So read my lips.
If you are trying to test the pump for resistance you need to go between earth and each of the fuse terminals with the fuse out ,ignition off .One of them should show a low resistance if the motor is good . If both show infinity the pump is bad .