After heavy rain when I open door of xj40 there is a buzzing and bulb failure light on indicaters do not work

the common prob with old xj40 with odd readings on insrument pack is bad connection inside the pack itself with good eyesight carefull dismantling and a soldering iron it can be fixed

check the way the system is wired up as there appears that that is where the problem is located

Sounds like either a short in the door switch which controls both sides, or the relay is bad. I doubt if both motors and regulators would go at the same time. If you left the door open in a heavy rain or an unnatural amount of water got in the switch a short could be the problem. Check the relay first...then the switch

sounds like the indicater relay is faulty change it should be in under bonnet fuse box

Have radiator pressure test done for head and gasket problems. check timing and fuel pressures. If you have a viscous fan hub it will indicat failure by heating up when stopped at lights or pulling heavy at high engine rpms. IF electric fans check for correct operation. Check tension of fan belts and replace if not slightly above pully flange edge.

Hi Joe, I believe you have a defective door switch (if you didn't leave the door open?) Check the switch. Regards John

if the rest of your dash and instrument lights work and it's just the speedo that stays dark you have a bulb burnt out in your dash cluster.

have you checked the bulbs?

bulb failure light is from one of the relays found attached to each light... if one of them sticks the dash light will go on even if all the lights work.... solution.. buy inexpensive relays on line and substitute until you find the faulty one.....

First check the power window fuse,
1. Remove the door panel for the affected window.
2. Locate and remove the bolts holding the regulator to the door; it is likely you will have to manually lower the window in order to access the bolts.
3. Remove the old regulator, disconnect all wiring and check the wiring , replace the old regulator with a new one if defective.
4. Tighten the bolts holding the new regulator and reinstall the moisture barrier. Make sure all the wires are put back in the door before closing the door panel.
5. Engage the power window switch and the new regulator should work unimpeded.