My problems are threefold, and I wonder if they can be related as they all started around the same time.
1) We get no heat from the car this season EXCEPT for once. How can that be? I've been trying to track down the reason and keep coming back to the auxiliary heater pump. The crazy thing is, after realizing it wasn't working in September, it did work once, and very well one day only. After that I can't get any heat again. Since it started this I've drained the coolant system a few time to clear the system for fresh coolant which I have yet to add until I solve this problem. By the way, no sludge came out or was evident in the system. After a number of flushes, I pulled the hoses on the heater core and flushed that. Same deal, just coolant and no sludge, but it was apparent that this had not mixed with the rest of the coolant system since I started flushing. I tried to force the pump to work by jumping power from the headlight to the pump through power from the headlight relay to the pump relay, but heard nothing. I get no ground evidence through the pump relay. Thinking the pump motor brushes may not be making contact. Just weird that it did work that one time out of the blue. And being a 1997 car, the pump is all the way in the tranny tunnel. Looks impossible to get to.


Problem 2) The drivers heated seat now has a mind of it's own. Sometimes the light is on, sometimes not. Sometimes the heater is on, sometimes not. No correlation between the two, and pushing the button has no effect in any mode.


Problem 3) Driver's seat keeps blowing it's fuse. New fuse in and the seat works, but I haven't been able to tell when it blows as it seems to do so at random times afterwards.


So any help with any of these issues would be greatly appreciated. Especially the first as the car is now rendered un-drivable until spring. They all started around the same time and all have some wiring that may be related in proximity. Can one be effecting another, or all? (Is Prince Lucas back to haunt me?)


Thanks for any thoughts and advice in advance.
Mark R.

 

Hi mark,
For the pump, remove it, fit new brushes then bench test it first before refitting.

2 and 3 could be related. Remove the seat and check the wiring harness for signs of broken insulation. This harness is prone to damage over time.

You could also disconnect the control module, check and clean the connectors and reconnect.

Biggest job will be the pump.

Hope this helps,

 

+1, competely agree.

Here is a how to on the heater pump from RaceDiagnostics: https://www.jaguarforums.com/forum/x...val-how-96841/

The wiring under the seat is prone to abrasion of the insulation and needs a careful visual inspection with the seat removed.

 

WhiteXKR. Great link on the heater pump. I'll be tearing in tomorrow. Then the seat comes out.


Many thanks,
Mark

 

Make sure you have a pair of cable operated hose clamp pliers...it is next to impossible without them to reach the clamps.

 

Problem #2- does having the headlights on make a difference? I ask because my little red lights for seat heat do not work when the lights are on, although the heat works.

 

WhiteXKR, Yes I have the hose clamp pliers. They are great. Thanks.


Rob, I don't think the headlights matter. I've driven many times during the day hand have experienced the problem then. But that's a good thing to take note of next time I go out. Did you get yours corrected? If so, how?
Mark


Mark

 

Mark,

I haven't solved my light issue yet. Since the heat works, ,it's low on the list of projects. See if you can solve the wiring and fuse issues first, then if the problem persists, swap the relays for the driver and passenger heat and see what happens. The red light is put on by the relay, indicating that power is going to the seat.

 

OK, Got the pump out and only had to take the upper throttle body off to do it, plus detaching any wiring in the area to clear the exit route. Epic battle but I don't think I broke anything in the process. Plenty of blood though. Always a good sign.


And the verdict is in. It's the pump motor. I opened the motor and one of the brushes is just a sliver, and the other is completely gone. Nothing but wire. Now to try and find replacement brushes.


Rob, Will take your advise on the seats when I get the pump back together and installed.
Mark

 

Several members have said they found brushes at appliance repair shops.

 

So, I ordered new brushes on line. Bought two sizes just over the measured size (.19x.19xsmall) They were easy to fit with just a bit of sanding. Got it all together and applied power and got - sparks and hot wires. No spinning. Something was grounded. Did web refresher on how DC motors work and concluded the windings were shorted. However, I was confused about the function and reason for the diode wired directly between the two brushes. I did a continuity test on it and it buzzed in both directions. I thought that it would do so because the power may have circumvented the diode and had gone through the brushes and shorted armature. So I hunted for and found a small elec motor shop nearby. He went through the same exercises and found nothinng wrong with any of the normal components, but it still didn't run. I mentioned about the diode and he did a continuity test on it, like I did, and got the same results. He, however, didn't beleve my short theory and just cut one end of the diode, and the motor started running. The diode was fried. We assume the diode is in there to protect the pump, or whatever is hooked up to the motor in other applications from backward wiring. But with our dedicated wiring and connectors, we shouldn't need it. (again, my theory)

So the pump is in, and we have heat. Total cost - $25 for brushes (2 sets plus shipping), and $20.00 for the local expert. I'm a happy guy.

 

Actually the diode reduces the electrical noise the motor induces into the electrical system of the car. You might want to make sure you do not 'hear' the motor on your radio. Chances are it would most affect AM radio.

 

WhiteXKR,
Interesting comment. If you're right, it should not be a problem. The only time we listen to am is to hear baseball, and we usually don't have the heat on then. Although playoff's could be a problem, but our team currently doesn't look like they are destined for that any time soon.
Mark