We recently replaced the battery on our 95 XJS conv., and now all of a sudden the top will not go down electronically. The manual method works fine (at least we know it is not likely a mechanical jam), but the small windows dont roll down when you do in manually.

We pulled the top switch from the ski slope and the switch seems to be connected and in good order.

What else should we check? This never happened before.

 

95xjsconv,

When you say that the switch is ok, have you checked it properly for current flows on each side?

If the switch is ok, the easiest way is to check for current on the window and hood down relays. If you read through your workshop manual, you'll see the identification of the down relays.

If you're not seeing current to the down relays, the chances are that it's the input signals to the ecu from either the gear selector or the handbrake switch. The handbrake not being properly applied or the switch not operating correctly is a common cause.

The workshop manual is very good at describing the whole operation and the circuit flows. Have a read through that section and you'll find the problem in no time!

Good luck

Paul

 

thank you PTJS1, that was very informative. It also reminded me of something - does the handbreak need to be applied to make the top go down?

This might be the cause of the problem, or a least a good lead. In 5 months of owning the car, I haven't noticed that we had to have the handbrake on in order for the top to go down, I thought it just had to be in "P".

Perhaps the system was acting up before and allowing us to put the top down with the handbrake off, and now after the battery was out for awhile, the ECU reset and now the system is actually working "correctly"...

either way we will check the current and see what exactly is happening. THANKS!

 

On my 89 the hand brake has to be on and make sure it is in park

 

All XJS convertibles need to have the handbrake applied, ignition in position I or II, and the transmission in Park or Neutral for hood to operate.

Paul