central locking

[TOPTON]

I have just bought my first Jag, an 89 reg XJ6. Almost immaculate condition. The 2.9 straight six does lack a bit of get up and go but is very smooth.

However it does suffer from a couple of niggly electrical problems,

Horn doesn't work
False readings on the diagnostic screen and the wipers don't self park.

My main concern is the central locking. When I was buying the car, all the doors opened and locked as they were supposed to do. Now both rear doors refuse to unlock. The buttons seem to go up and then straight back down again to re lock whilst the front doors remain unlocked.

Is this a simple fix or is there no such thing on a jag

[a8hex]

TOPTON said:

I have just bought my first Jag, an 89 reg XJ6. Almost immaculate condition. The 2.9 straight six does lack a bit of get up and go but is very smooth.

However it does suffer from a couple of niggly electrical problems,

Horn doesn't work
False readings on the diagnostic screen and the wipers don't self park.

My main concern is the central locking. When I was buying the car, all the doors opened and locked as they were supposed to do. Now both rear doors refuse to unlock. The buttons seem to go up and then straight back down again to re lock whilst the front doors remain unlocked.

Is this a simple fix or is there no such thing on a jag

Not sure about the 89 model (so an XJ40) but with my 84 (X300) the central locking can play up if the voltage is a fraction low. Fortunately I haven't seen the problem for a while but cold mornings when I hadn't used the car for a while was a time when it would play up.
Having said that, this months Jaguar World mag has an article about X300s and there is a comment about XJ40 central locking in there, I'll try and dig it out this evening.

[TOPTON]

Seems to be a feature of the model, they are working fine again now. Indicators play up a bit also, only on left though, sometimes switching on and sometimes not, then sometimes not switching off unless hazard switch is ficked on/off.
I guess Jag electrics were built by the same guy that worked for TVR.

The car has only done 2000 miles in the last 10 years so maybe lack of use

[Jaguar steve]

The 40 was the first Jaguar to use low current command signals and electronic module switching instead of a conventional wiring harness. This means that a lot of the connectors in the system only carry a very low control current rather than the actual amount of juice needed to operate whatever it is being turned on. The actual switching is done by the module itself rather than the controls and switches you operate in the car.

Often a fault like yours is either due to low battery voltage or a poor quality connection somewhere in the system. Somtimes all you ned to do is disconnect and reconnect a harness plug or module and by doing so clean the contacts.

See if you can find the likley connections in a Heynes manual, or join the Jaguar Enthusiasts Club and ask for some technicial advice. Joining the JEC will cost you less than half an hours labour in a garage and is a bargain for the technical resources alone.

[NormanD]

Jaguar steve said:

.... or join the Jaguar Enthusiasts Club and ask for some technicial advice. Joining the JEC will cost you less than half an hours labour in a garage and is a bargain for the technical resources alone.

I agree with joining the JEC, good monthley mag and contacts with cocal Indipendants

I am from the Surrey Region but you can join National through our web site http://www.jaguar-enthusiasts.org.uk/register.html

[Cecil]

Agreed, the JEC is well worth the membership, although their web forums are not the best, if you are stuck try searching the forums on Jag Lovers http://forums.jag-lovers.org/