Wiper won't run with relays replaced and speakers make noise when brake pedal pressed

Hi fellow Jag lovers, and the gurus who I haven’t talked to for years !!

I have a strange one that is clear evidence of an electrical short, but just checking in case anybody has seen these issues before.

Had my plugs and coil packs replaced, and the mechanic kindly cleaned my engine bay (gggrrr), and lo and behold, the wiper has stopped working. I replaced the fuse and the relays as a cheap fix up front, and it will still not come on.
Interestingly though, when i start the car and pump the brake pedal, each press results in static from the car stereo speakers…seems like a short in there somewhere sending an electrical spike.
Anybody know the best place to start here ?

Shane , 1978 XJJ66 and 1998 X308…(original Jag Lovers forum member from the 1990’s)…:slight_smile:

Wow … now that’s very interesting … as to the radio thing … Was looking today at Harlem yet again, and still trying to figure out why no power to the radio or to the cig lighter (front), despite no blown fuses. I’ve pretty much decided it can’t be due to the new unprogrammed ignition key, as in any car those should both get power whenever the key is turned “on” - not necessary for the engine to be running. :thinking: I’m wondering if something shorted in the ignition system to cause them both to go out (I did find the heel panel fuse - 10 amp - for the radio was blown when I first discovered the disabled condition - but with a new one in it’s not blowing). I’m wondering if what you’re experiencing at present might be related to what eventually happened to Harlem. If so, be prepared for the radio to go out on you soon . :grimacing:

hi mate, let me now how you go getting the key programmed…i have a new one from jaguar matching my chassis, so unlocks doors but will not give me anything when i try to start…dealer said originally it would come programmed and blatantly lied…$200 for a key that doesn’t start the darn car…now local older model jag specialists want to charge me $150 to program it…grrr

That’s the going rate here … The one Jag dealership in this area (of FOUR) that still has a Tibbe machine cutter (and someone who knows how to operate it) ordered my blanks (2) and cut them (I had lost both of mine). They also had to look up the key code by Harlem’s VIN # to do so (after I showed proof of ownership :roll_eyes: ) b/c I never did write it down. :blush: Again, they were the only local dealership that could do so. Cost was like $120 per key. They never told me when they gave me the keys though that they had chips in them that needed to be programmed (and the gent who cut mine turned out to be a former client of mine from many years past - just a one-in-a-million coincidence :open_mouth: ). :angry: When I confronted them about it, they admitted they only have software now to program keys from 2012 MY to the present. :rage: After spending two weeks on the phone calling all around the Metroplex, I finally located ONE place here - a repair shop that specializes in classic year Jags - that has the software to program them. Cost $150 for both keys (which = one hour of labor time).

Maybe the OP should disconnect the battery and then start checking the earth connections under the bonnet. I think there are some at the front by water bottle and also the main thick lead and nuts that come through the bulkhead and go to the fuses boxes.

Though those would result in bigger problems that you currently have now, I assume it driver ok ?

Is the passenger footwell wet at all ?

Yes, that noise you describe sounds like a ground loop. Something with your grounding system is now…questionable?

Search through the forums for a grounding map for the car. It should reveal all of the ground points, then check 'em out, one at a time. Find them, clean them, grease them and reconnect them!

Interesting, AndyK & VK … So I wonder - would a (common) bad ground somehow account for my radio head unit and (front) cig. lighter not getting any power? :confused:

No, I wouldn’t assume that. Loss of power is something else…probably.

You’re going to have to get a wiring diagram for those two items and start at the fuses (assuming fuse has power) and work towards the radio/lighter.

Yep, that’s pretty much the plan. :thinking:

hi Veekay, i have searched the forum and cannot find this for the X308. I have the workshop manual and it also does not summarise the various grounding points…any idea how best to get the locations?

Hi Shane

Do a google search for “XJ Series Sedan 1998 Electrical Guide” and that will give you options to download the guide. Once you have that, it gives you details for the grounding points. Here’s one from the guide for my 2000 XJ8

thanks Mark, we will test all of these and see if it sorts it…thanks for the google search info, I can see that this electrical guide is 10 quid, and covers maybe more detail than the service workshop manual I have right? could be worth a purchase…

Look further down the search results - you’ll find places you can download for free.

I’ve found mine invaluable - saved me lots of money, I think, so worth paying if you have to but let me know if you struggle to find a free one.

Jagrepair.com has a ton of good stuff