Car is a 93 XJ6, XJ40. After installing two used blower motors for the a/c system yesterday, and replacing the blown 20A fuses for both blowers, only the passenger side blower worked. The radio was working fine too. However, today these three symptoms have come up.

I have checked the fuses and they seem fine.

1. Climate control has backround illumination but the red led indicators do not light up like they did the day before. Also, the blower motor does not work but worked yesterday.
2. The radio will not turn on. Only the red led for security seems to work.
3. I noticed that I
can shift the car out of park without the keys in the ignition.

Other info: The battery light on the dash has been on for the past two days indicating a problem in the charging system. I rev the motor to 2000rpm and the voltmeter never gets past 11.5. I will be servicing the alternator for this.

What could be causing these three things?

 

Sounds like you may have issues with the fuseboxes; dry and cracked solder joints are pretty common at this vintage!

Taking the fuses in and out also puts strain on the circuit boards - both of my footwell boxes had cracked joints.

Incidentally, the blower fuses are in the centre of the boards and get the most flexing / problems - neither of my blowers worked, issue was with the fuseboxes. I reflowed the solder and it fixed it. The radio not working could also be related to the footwell fuseboxes.

With the panel not lighting up, maybe the microswitch has failed? That could also account for the no-blower situation.

Sorry no ideas on the ign / shifter or battery issues.

Larry

 

Thanks. I will take the fuse boxes off for further inspection. I hear a noise as if the shift lock will click when I press the brake, but it does not lock the shifter in place when I remove the key, allowing the shifter to move while the key is out of the ignition. any ideas?

 

Not a fix. But I have had instances where I start the car, radio and climate control dead. turn off car..restart and it clears. Has happened 2 or 3 times in my 1994 in the 4 years I've owned, never troubleshooted as I just turn off car and restart. Will be looking to hear updates you may find.

 

supra-raleigh and skertz,

Larry's suggestion about the fuse boxes is a well-known and common problem and well worth checking. Another thought that comes to mind when reading about your issues is that your ignition switches may be failing, which is a very common problem on the XJ40. This is the electrical switch attached to the inner end of the ignition lock barrel. Depending on the position of the key, the ignition switch connects various combinations of four wires IIRC. Some "auxilliary" components, such as the climate control system and radio, are supposed to be powered in both key Positions I and II, but maybe not in the START position (the spring-loaded Position III). As the switch terminals wear, sometimes the auxilliary connection becomes weak so that in key Position II the auxilliary circuits lose their power. It would take some study of the Electrical Schematic to confirm that your symptoms point to the ignition switch, but you can test the switch easily enough with an ohmmeter at its electrical connector, which is inside the steering wheel cowl. The photos at the link below show the switch replacement process on our '93, but I think the earlier cars are similar except the electrical connector is different:

Welcome to Jag-lovers - Members Photo Viewing Page


And if your ignition switch tests okay, here are photos showing how to service the fuseboxes:

Welcome to Jag-lovers - Members Photo Viewing Page

P.S. supra-raleigh, your battery light issue could possibly be related to the ignition switch also; however, I suspect that your ability to shift into gear without the keys in the ignition is a separate issue with the gearshift interlock. A few years ago I broke the gearshift lock on our '93 when the car stalled in an intersection while our son was driving and when I arrived on the scene I couldn't get it to start or go into Neutral so we could push it out of the road. I forced the gearshift lever into Neutral and broke the lock, but we've just been driving it that way ever since and I haven't worried about it. One of these days it may make its way to the top of my priority list, but at the current rate of more urgent auto repair issues, I may never get around to it!

Cheers,

Don

 

I ordered a new alternator brush holder off ebay. I will test the alternator before and after I install the new brush holder. Also, the car has just 80k miles on it, so those reading this post can have something to compare. I also plan on taking the Autozone battery and getting a second opinion at O'reilly's.

I will look into the rectifier and regulator as well. However, could someone explain the difference between these two things and the different symptoms that manifest as a result of each one failing?

 

Haven't been able to test the ignition switch and will as this problem reared again tonight while testing the blower motors and a different climate control module. Sometimes it works and others it did not.

 

Try this as I had similar issue but was more concerned with my blower stop working. Went through the fuse panels and found no issues. But I tracked it to a large relay module. Under right dash, DBC 10009. Aux power, sidelights, and radio. My taillights work 10% of time. Radio and climate control come an go upon start of vehicle. Then blower started issues. A couple whacks on the relay with screwdriver hammer and all works. Confirms that the relay switches inside are sticking. I used to have to do this for a relay to the AC clutch. open bonnet and tap relay. I am now looking for a DBC1009 module on eBay to replace.

 

Thanks skertz. What color is the DBC10009 module? What must be removed to gain access?

UPDATE
Also, I installed a new brush holder and regulator, charged the battery overnight and the battery warning light turned off. However when I rev the motor past 4000rpm, the alternator emits sparks. Perhaps the new brush holder has to wear in to be properly seated. I am open to your thoughts.

 

Its the yellow one under the RH dash. my '94 has no glovebox but its behind that panel. I created an album Jaguar Forums - Jaguar Enthusiasts Forum - skertz's Album: Skertz there is a yellow, blue and red. It will be labeled DBC 10009.

 

skertz,

A very common problem on those relay modules is cold or starved solder joints where the relays are soldered to the circuit board. The cases can be opened, the solder reflowed and supplemented with new solder, and the modules will usually then last forever. I don't have photos of the inside of one of those relay modules, but I do have some shots of our fuseboxes, which suffer from the same bad solder joints and need the same service:

Welcome to Jag-lovers - Members Photo Viewing Page



supra-raleigh,

You've already had your knee bolsters out to work on your blower motor housings, but for others who will read this thread in the future, here are instructions for removing the passenger side knee bolster for access to the relay modules:

Welcome to Jag-lovers - Members Photo Viewing Page


And here are photos of the relay modules as arranged in our '93, which has a glove box rather than an airbag as in skertz's '94:

Welcome to Jag-lovers - Members Photo Viewing Page


Cheers,

Don

 

I removed the alternator again while I was installing some new coolant hoses. I took it to get tested and it failed - only 10V or so. I had an alternator specialist go through it, new bearings, new rectifier and the shaft was resurfaced. They even cleaned it up and painted it. Upon installation, the voltmeter now reads over 14V as it should. The climate control along with the blowers work as they should along with the radio!!!!!! The gear shift interlock is still an issue however.

 

Now the climate control and radio work intermitantly. If I bang on the passenger side under the glove box, the climate control and radio come back on together. So, I guess I will look into that yellow relay box. Thanks