Hi,

I've got a new problem!! When I switch the ignition on or run the engine some of the dash warning lights flicker.
When I switch the headlights on they go out, if I switch the headlights off they start flickering again.
Worse than that sometimes they behave perfectly normally, making it very difficult to fault find!!
THe radio is also intermittent if that might be related.

Any ideas or solutions most welcome.

 

Sounds like lose wire/ground unplug some connections and reconnect and find all your grounds and check them I'd guess

 

Agreed, a bad ground is the likely culprit.

Remove cluster, clean all contact points on the printed circuit, add a redundant ground.

While you're rooting around in the dash clean every ground point you can find....might as wll clean and tighten all the fuse clips, connectors, etc you can put your hands on while you're at it. Heck, make a full day of it and go bumper to bumper.

Sounds like a lot of work but what you're really doing is curing about 90% of the infamous "Lucas" problems.

Cheers
DD

 

Already gone through 90% of the connectors, cleaned and lubed. God, those plugs are tight!
Will try to get to the earths behind /under the dash next.

 

It never rains but it pours!!
Now the headlights are playing up. Won't latch onto main beams with the engine running, sometimes will with the engine and ignition switchrd on.
Only good thing (?) was whilst I was trying to, unsucessfully, resolve it I found that the headlight was missing the bulb retaining wire and the adjusters were not working so fixed those at least.
THis car is going backwards!!

 

The symptoms you have described are almost 100% bad ground. What you have is a high resistance to ground in one or more of the ground terminals, this is the connection between the terminal and the body of the car - so you need to remove each ground connection from the car and clean the terminal and connection area, you could also use star washers to improve the grounding. Then if you want to fix this for ever use Marine Seal (I don't know what they call it in the UK) but it is what is used on boats to seal each electrical connection.

 

Thanks, I cleaned the ones in the engine bay, where are the ones (presume there's at least one behind the instrument panel) inside the car and how do I get to them.

Also how do I get the radio out.
Edit (found a link for the radio http://f64.nu/xjsradio/ )

 

A quick update.

Sorted out all the problems......for now!

The headlights were due to a faulty headlight relay, I ordered a replacement but whilst waiting for that, I took the faulty one apart. I traced the faulty to a blown transistor which, once I'd replaced it, cured the fault. At least I've now I've got the headlights working and a spare relay.

The flashing warning lights were due to a loose connector on the Factory Jag alarm, despite the fact that it's got a Meta alarm fitted, go figure! Took me a while to track that one down!

Once I'd fixed these two that left the radio, checked every wire and fuse, and finally decided to take the radio out. It did the same on the bench. I took it apart and traced the fault to a broken track and a broken (one leg) smd transistor that applied a signal to the main "processor" to turn the whole thing on. Tracked down the transistor and fixed it.

So it's now all working till the next problem.....