I want to relay my experience in repairing my Power Antenna in case someone in future might find it useful.

Symptom: Power Antenna comes on and stays on even though it has reached the fully up or down position. May be the precursor to burning up the antenna motor if it occurred while driving. You hear a loud "thump thump thump" noise as if the antenna wants to keep moving but it has clearly gotten where it should be.

Diagnosis: Hopefully you find this out early because it probably will burn up your antenna motor or deflate your battery. I found my issue out when the battery died. I recharged it only to hear that noise.
In the trunk to the left (as you face forwards) you will find the antenna motor. It is encased in a metal bracket to the left of the fuel pump. The issue can be replicated by removing the connections from the green power antenna relay (this relay just controls which of the wires to the motor completes a circuit and hence runs. It doesn't do anything else.) and jumping the purple constant power wire to the Blue/Red wire or the Blue/White wire. This will cause the antenna to run in either the up or down direction. If the antenna goes up and down when jumped then continue looking for the problem. If the Antenna Motor turns but the antenna does not go up and down then the antenna cable is probably broken. Mine went up and down, so the cable was good. A Picture of the Wiring Diagram is below. UR = Blue/Red, UW = Blue/White. The little egg shaped symbol in the Antenna Motor symbolizes the limit switch. This switch decides when to stop the motor running when the antenna reaches the end of its travel,

Steps:
1). Remove the Antenna. There are directions in section 86.xx.xx in the manual. And in this (https://www.jaguarforums.com/forum/x...a-mast-101665/) thread. I attach a picture (Antenna Motor) of the motor as removed. It is Part DAC3542 if you can find one that isn't already broken.

2) Remove that nut in the center of the motor housing. This will allow you to pull the housing off.

3) You will be looking at some metal bits on the top. They have many little washers and snap rings. The photo titled "Cover Off" shows what you find when you remove the housing cover. You must be careful to keep the order of the washers and snap rings straight. I wrote them down and kept them in a stack which was easy since they are covered in grease. I used a pair of needle nose pliers to turn the toothed retaining thing there which has a spring underneath. In any case, you get the picture. Keep taking retainers and washers off until the only thing left is a white plastic nut. That is molded and cannot be turned.

4) Once you've taken all the retainers off (one of the last ones is a snap ring that you can widen by putting the ends of your needle nose between the ends and opening. This bends the snap ring out enough to remove it. No other way to do it.) You will be looking at something like the picture titled "Spool Removed".

5) In the Spool Removed picture notice a few things. First the yellowish crud. I have no idea what that is but the bottom of the motor was filled with it. I cleaned it all out. I am sure that this stuff retained water and kept everything in there nice and moist. Couldn't have been good for the motor. Second, you can see the "White nut" I mentioned. As you can now see, it is molded to the sprocket. When engaged the motor spins the auger thing on the top of the picture, which in turn rotates the sprocket which in turn rotates the cord that pushes or pulls the antenna. You can see the cord which resembles large gauge weed wacker cord. (BTW, I'm sure weed wacker cord would prove a suitable replacement for that). To the right, you will see a small copper tension/spring thing on a post. That needs to come out. But don't forget it or you'll have to do all this over again when you find it on the table after finishing your last bolt!

6) Remove the Sprocket and now we can see what is what. In "Switch with Cover" we're finally getting to the root of the problem. You can still see the copper/tension spring thing there. That thing is resting on a white cover that has a sprocket of its own. A little snowflakey thing. Lift that cover off. Again be careful, it has a washer stuck to it with grease..

7) The next picture is a close up of the limit switch.("Close Up Switch"). This picture is actually taken after I had started the repair. There are some important things to notice about this. First, in my case, the problem began on the upper (as relates to as shown in the picture) horizontal surface of the white plastic piece which holds the copper contacts. Overheating had caused that plastic to burn and bubble up. In the picture I had used a new xacto knife blade to reform that piece. The bubbling had affected the copper contacts. You see, the copper contacts there look like it is one piece but it really two. The upper dome shaped contact that looks a bit silvery is actually a ground. The lower copper contact surrounds that silvery contact but does not touch it. The contact with the spring on it pops up and touches that silvery one when pressure is applied to the longer copper bit that extends past the contact. Since plastic had bubbled up underneath the copper contact, it could not make contact as shown in the picture. The bubble kept it from breaking with the upper contact. Finally you'll notice a flat spot on the green piece of the sprocket. It looks like a tab that pushes down, but it is actually melted. This means that when that green piece rotates to the right and is supposed to push on the longer copper bit, it didn't thus further preventing the breaking of contact.

8) Job one was to shave that bubble down. That was fairly quick and easy. The xacto knife sculpted the plastic piece into a decent resemblance of its old self. The harder job was that green piece. You see that plays a critical role in this. The picture called "First Repair Attempt" shows the piece with some attempted modification (which didn't work btw). In that picture you can see on the left of the green piece that melted tab had fallen off. Both sides of that green piece should have a lobe and that lobe is what pushes down on the longer copper bit. I attempted to fashion a piece of plastic (the black that you see) that I could stick to the green piece on the top that would replicate the missing lobe. But the green plastic is soft plastic and glue wouldn't stick. I heated up pins with the idea of pinning the plastic pieces together but it didn't hold and the harder plastic making up the repair finally just broke apart.

9) I didn't take a good picture of what I eventually did but you can see it and get the idea from the photo called "Final Repair". I had bent a few common pins in the previous attempts and I figured I could drive a pin (heat the pin up in a candle flame) in the end of the broken plastic (heat the pin and drive it in the middle and have it replicate the lobe) . So I did this and then cut the pin off at the end, initially too long, and then just nipping a bit at a time until I could get the pin to turn smoothly in its enclosure. The bend in the pin is important because it gave the pin the height to get on top of the longer copper bit to press it down. In the photo you can just see the pin leading from the edge of the green piece and stopping behind the longer copper bit. You can see it better if you really zoom in. (Ctrl + Scroll in). Now when the sprocket turns the pin hits the longer copper bit and the circuit does its thing.

I put it all back together (assembly in reverse) expecting a smoking ruin. The first few attempts of turning the radio on resulted in the antenna raising only a few inches and stopping. It raised and lowered correctly, but only say three inches. I was trying to do that by jumping the wires as mentioned above. On a lark I hooked up the radio properly and powered it on (I now have a new battery, LOL) and presto! Full up and down stopping normally.

I tested it out half dozen times and it works.

I don't know how long this will last. I don't see why it shouldn't stay put for quite some time since the only pressure on the pin would be to drive it deeper into the green plastic. In any case, if someone has one of these undamaged green pieces lying around I'd replace my bodged job with a proper one if you will send it to me.

I wrote this up for a couple reasons. One was that if someone else had this problem maybe what I did might work for them as well. The other purpose was to get some pictures of the inside of that motor on the web. I couldn't find any.

 

Good info. With these small items getting to be more scarce, it is good to know how to put life back into them. And you are right ,..there is not much if any info anywhere on this subject.

I got lucky and have squirreled away a few spares (antennas with motors, cables, masts and electrical wiring) over the years - thinking that, in the future - not having a replacement should mine crap out, might prove to be problematic. These antennas seem to be unique - needing to fit inside the small space in the rear wing it lives in.

Good thread.. thanks for your effort. I have copied the info to my master Jaguar file - where a lot of good stuff has been saved.

 

Good work, good write-up, thanks!

I think the OEM antennas were "Hirschman" brand. Compare the innards of the OEM versus today's el-cheapo stuff.

Cheers
DD