Back to seat belts, new issue

(David Martin) #1

The warning lights are on when buckled in. 89 xj40, I noticed a magnet on the passive buckle, is this what tells the light to come on? I have not tried the emergency clip yet to see if that stops it, just trying to get input as to possable causes.

(Grooveman) #2

David …

Hmmm … a good question.

On my 89 XJ40 the seat belt warning light would come on for about 15 seconds after I started and then go out. It definitely had nothing to do with the lap belt because there is no electrical connection to the buckle. Did the passive (attack) shoulder belt cause the light to go out, I don’t think so. The electrical connections in the seat belt housing are for the motor and the micro switch that limits the backward travel of the cable that the seat belt hooks to. The forward position is limited by a mechanical clock-like switch also in the housing.

The red arrows indicate the electrical connections for the motor and limit switch.

After I removed the passive system and went to a standard seat belt system I still get the warning light for about 15 seconds and then it goes out.

(David Martin) #3

I will try the emergency clips and see if they go out, after that maybe the dealer can fix it when they fix the rest of the seat belt issues! Lol, just wondering what the magnet is for on the passive lock mechanism it is on the part that locks in the pillar.

(Grooveman) #4

Davis …

Can you take a picture of the magnet ?

(David Martin) #5

(David Martin) #6

That is the passive restraint

( Larry ) #7

I’d keep my credit cards in the opposite pocket if I were you :flushed:

(David Martin) #8

Anyone know what size torx drive takes out the seat bolts and where I can get one?

(Grooveman) #9

David …

I have no idea what function the magnet has !!

Since there is no electrical signal generated when you fasten the buckle of the shoulder belt (that has the magnet) to the traveling mechanism (red arrow) I can only guess that somehow it comes into play when the buckle is in the full retract position (blue arrow) ? But …

…in the past I had removed this entire system from my car TWICE for repairs. I disassembled everything and didn’t see anything that would explain the magnet. I may be wrong but I don’t remember seeing a magnet on my shoulder buckles.


(David Martin) #10

Well I would like to know what it is there for, someone must know on this site,pretty odd that it has not been mentioned before!

( Larry ) #11

It’s probably for ‘parking’ the loose end of the lap belt so you don’t have to drag it out from under your arse when you get in, no?

(Grooveman) #12

OK …

Good question, David is this the buckle from the lap or shoulder belt ? I was assuming it was the buckle that you hook the shoulder (attack) system to.

(David Martin) #13

Attack belt! On the buckle you dont have to undo, in a perfect world.

(Grooveman) #14

David …

It looks to me like Jaguar made different versions of this buckle system to comply with different country’s safety requirements when they exported them. My USA car definitely did not have a magnet on the buckle.

The ONLY purpose I can see with the magnet is that it must close a circuit when in the driving (closed)
position to turn out the seat belt light. But since it’s an automatic system that doesn’t make a whole lot of sense to me either.

BRYAN ALERT … BRYAN ALERT. We need your input.

Next to the meaning of life this is the greatest mystery I’ve come up against.

(Bryan N) #15


I am delighted to tell you that our UK spec XJ40s did not have the ‘attack’ type of seat belts so I know nothing about the mechanics of them.
I guess the Jag designers figured that we Brits were clever enough to remember to fasten our own seat belts before driving off - although the number of people caught by the cops for not wearing a seat belt these days is quite remarkable.

(David Martin) #16

The mystery continues, there are 2 switches, 1 magnetic and 1 mechanical. Must be stop switch and idiot light on dash.