Windshield Wipers & Electronics

XJ-S
1

Hi all,

Right after Christmas on my way back home, my '92 XJS 4.0 showed some really strange behaviour.

First off all, the windshield wipers suddenly stopped working (of course it rained like hell). After restarting the car a couple of times, they worked again. But after a few minutes, they began to slow down and eventually stopped again.

I thought the linkage might be the problem so I stopped at a gas station, removed all covers, sprayed WD-40 everywhere and removed the right wiper alltogether to decrease the resistance.

It didn’t feel like it helped at all. I realized the wipers would run for a few minutes and then stop for a few minutes and then work again. Like the motor was overheating or something of that sort.

I got super annoyed an frustrated (Dec 26th at around 10 pm!) so I opened the window a little to smoke a cigarette (don’t worry, I normally don’t do that in my XJS). Rain started to get worse so I wanted to close the window which didn’t work - the window just didn’t move. As you can imagine, that didn’t exactly help to improve my mood :smiley:

After a while the window closed (by the way, I have experienced that behaviour before, but usually the window closed after trying 3 or 4 times and maybe moving the window a little further down) and I made it home.

When I got home, I got out of the car to open the garage. When I got back into the car everything was dead. I turned the key and absolutely NOTHING happend. Not a single light flashed, the interior lights were off - a complete black out! I turned the key back and forth a couple of times and finally power returned and the car started.

Now I’m obviously wondering if these issues are somehow connected. The battery is a little undersized (I think 60Ah) and old, maybe there is just a lack of power. On the other hand, this would mean there’s a problem with the generator as well. The indicator on the dashboard showes a healthy voltage.

I haven’t moved the car since but now weather is improving and I’m planning a trip with a girl on the weekend. Which I don’t want to end with her whatching me yelling at the windshild wipers :wink:

Any thoughts?

Thanks
Jannik

2

First- Check all the battery cable connections, including the two important posts on the engine side of the firewall.
Second- Let the girl stay home until you get the problem fixed.

1 Like
3

I wouldn’t trust the volt meter on the dash. Much better to get a basic volt/amp/ohm meter and check the alternator output directly, easily had for less than $10 - pretty much an essential item if you own a Jaguar. The battery may be part of the problem (how old is it?), but you need to see at least 13.5V out of your alternator. Both at the terminals on the alternator, and a similar value back at the battery.

1 Like
4

And remember that both of those posts also extend into the passenger side of the firewall, and the bad connections could be on that side.

2 Likes
6

Thanks for the advice! I’ll check the connections as well as the voltage at both battery and alternator.
Seems like you think it is an electrical rather than a mechanical issue (at least the windshield wiper part). Maybe I just get a new battery and see if that does the trick.

7

Why would you do that?

8

Because the current one is old and undersized. But you are right, that would be a lucky shot…