After a search of old threads I found bits that tap dance around this issue but nothing exactly like what is happening to my car at the moment.

If I try to start the car, one of three things happens: 1. The car starts in Park, 2. The car doesn't start in Park but will start in Neutral, 3. The car doesn't start in P or N. This happens irregularly and seems to be more apparent after the car has been driven.

My first assumption is that the safety switch in the shifter is going bad or is dirty. If that is the case, is it easy to remove/replace/clean?

Insight and similar experiences in this matter are greatly appreciate. Not driving the car more than 5 miles away from the house these days in case it has to be towed (AAA max allowable tow).

 

Here's some "no crank" information

Engine Will Not Crank Checklist


Next time this happens remove the white/red wire from the starter relay and jump it to 12volts. If the starter operates you KNOW that it's a problem up stream and not the starter itself, at least.

The article linked above covers most of the basesso i won't repeat them here.

Your safety switch is on the left side of the transmission and, by the way, also operates the reverse lights. You might try fussing with the adjustment.....just loosen the small bolt so the switch can be moved to find the sweet spot. A helper top side makes the job much easier.

I've heard that some switches don't have a slot to allow for adjustment. If yours doesn't just remove the switch and elongate the hole into a slot. The switch operates in a rotary fashion so it swings to and fro in an arc for adjustment.

Cheers
DD

 

Doug, that's great advice! You da man.

 

Ok Doug, I will apply the advice in your reply and the link and report back my findings. If it is the relay, that would be an easy fix.

 

Ok so this problem still persists. I have checked and cleaned terminals to starter/battery. No change. Went under the car. I saw that the switch that the shifter linkage is hooked to was loose. The tiny bolt that secures it to the transmission was almost falling out. Put it back in and thought "thats it, what an easy fix"... but no dice. Still an issue. In fact it now starts more consistently in N than in P.

Is it possible that the little switch is bad and needs to be replaced? I hope not because the wires look to run up the transmission to an impossible place to reach.

 

Did you adjust the switch or just tighten down the little screw?

Cheers
DD

 

Just tightened it down. I see that it rotates on the axis of the small bolt that holds it on the trans but wasnt sure about adjusting it.... is this a two person job? How do you adjust it properly?

 

Yeah, put the shift to "P" and have a helper hold the key to "start" while you rotate the switch.

Might wanna pull the coil wire so the engine doesn't start while you're under there.

Or, if no helper available.....

Put the gearshift in "R" and adjust the switch so the reverse lights come on. If it's adjusted in "R" it should be adjusted in "P" as well.

I've heard that some of the switches are not slotted to allow for rotation/adjustment. If so, you'll have to remove the switch and elongate the screw hole.

If you really get fed up just remove the black/green wire from the starter relay and run it to a permanent ground. This defeats the safety switch with obvious risks.

Cheers
DD

 

Ok, I will try adjusting it first. Really dont want to bypass it... the wife drives it most of the time and that can be a recipe for disaster!

Will report back results and try to take pics for this thread so others can see where I am working on the car.

 

Doug,

Aside from not starting in P and starting in N, my car tends to roll back when I put it in P. I have to place it in P several times before I will get to park the car. Does this mean there is an actual transmission problem or is it still a neutral safety switch issue?

 

Two issues. I am not sure if they are related.


1. The shift lever linkage on the transmission is not adjusted to be in sync with the position of the shifter. Therefore, shifting to drive is not always completed properly. relation to the shift tower to transmission.


2. The swaged end of the shift cable is failing. Inconsistent relation of shifter to shifted!!


3. Get clever as to how to see if the reverse lamps come on as you are under the car, rotating the shifter. Big mirror, so you can see them. Closed garage door, and you might see the illumination. Remove the glass and lamp and insert a dummy extension with lamp.


4. Abandon the N?s back up light switch and as you say inaccessible harness,
That is what I did on my conversion. There is a block on the nose of the shift tower that acts as a spacer. It can be removed and another microswitch added.
Wire in your own "ground the starter relay" wire.


5. Forget the back up lamp feature. they are kinda weak to illuminate much. But, OTH, they do advise others that you are backing.


6.So, build a new partial system. An XJS switch can be mounted to the side of the tower. Clamped actually. The wire to the lamps is near by. Cut and attach. Bring in an new ignition on wire. There are a couple nearby.


True, the long way around.


Carl

 

Thanks, Carl. I am a total newbie to this.

I just got under the car, found the neutral switch, loosened the bolt (it was pretty tight), but could not rotate anything. Then with a loose bolt, I got in the car and shifted the gear back and forth (P-R-N-D) couple of times, tried starting on P and it worked!

I tightened the bolt and done! I think luck solved my problem LOL (not sure for how long though). I have no idea what I did there.

My parking brakes are very spongy, I think the movement when parked on hills/ inclinations somehow had to do with the maladjustment of the neutral safety switch???

 

I think you stumbled on to a classic Jaguar fix. Exercise the part. You did a form of that by loosing and retightening. Exactly why, you may never know.


I've been chasing a pride of Jaguar electrics. I fixed one, merely by removing and replacing a glass 35 amp SAE fuse. Not an original Lucas, as it had no paper insert.
Clue: Some one was there before me.


Good work. and, progress in "understanding" your new charge!


It works. Can't beat that.


Carl

 

if the transmission switch adjustment does not resolve the problam,

you need to check to see if you have an Inhibit Roller Switch on the front, right side of the Shifter itself. (see picture below).

this roller switch is fitted to some years of XJ-6, but I do not know about the 1986 year; if your car has the roller switch, it could be the cause of the problem.

you will have to remove the plastic tray and lid catch under the center console lid, remove the center screw at the top of the ski slope, then disconnect all the window, sunroof, and master switches from behind the panel, to be able to lift the panel around the shifter complete with ashtrays.

then you need to remove shifter knobs and the 4 nuts around the shifter itself to remove the shift indicator housing. Observe there are ground wires connected to the shifter indicator housing stubs.

only THEN you can see the switch which controls the Inhibit / Cruise control activation in conjunction with the shifter. If the Cruise control does not engage in the D position of the shifter, the roller switch is suspect.

adjustment of the switch is covered in the Factory Service Manual which you can download here in this forum.

 

Yup, brings back memories. When I did the conversion, I had the cubby lid and ski slope out. Shift tower wires disconnected and the tower removed.


I needed access to the connector to the transducer for another reason. Just could not find it in the tunnel. Very close quarters. I found a different way to do it. Not so good, though, needs another redo. Speedo now inaccurate in spite of an electronic device that is suppose to match pulses. Jaguar to GM. speed at 45 MPOH is a real 25 MPH.


Same with the connector for the switch on the left side of the BW 66. I only needed that for reverse lamps. Id'd the wire. Cut it and connected to the switch now on the tower. Found a proper power source in the shifter cavity.


Yup, as I understand, some cars have two micro switches as per your illustration. One is for neutral start. The other is to interrupt the cruise control if activated in N or P.


Jaguar Schematics S57 is invaluable for this kind of stuff.


if the weather is decent, I'll do a test run on y car. if it doesn't mess up, I'll finnish the fuse check and button it up. Might use a ramp or two to ease the upside down on position to do the fuse extractions.


Carl

 

I've never been able to nail down exactly when the change was made from the gearshift mounted inhibit switch to the transmission mounted. But, to save time spent exploring, you'll either have one or the other. In this case, since there's a trans mounted inhibit/safety/neutral switch there won't be a gearshift mounted one.

Cheers
DD

 

Jose,

My cruise control does not work, so I know what to check next. Thanks!

John

UPDATE:

Thanks again Doug, you might have saved me hours of work

 

you bet John.

that switch is but one of a number of things to check if you are trying to get the Cruise Control working;

1) the on-off switch on top of the shifter's housing needs to be ON when you want to engage the cruise,

2) then there's the button on the turn signals stalk switch which you press after 45 mph to engage the cruise,

3) then there's the cruise control module located on the passenger side, under the dash,

4) then there's the engine compartment cruise control module which needs to be checked, especially the black rubber accordion.

 

Jose:


One more on cruise control. The switch next to the stop light switch behind the brake pedal arm. Both mounted on the same bracket.


The one for CC is an interrupt. Default is connect when brake pedal not pressed. So, pressing the brake interrupts the CC.


Of course, the other default is open and closes on brake pedal application causing the brake lights to illuminate.


S57 Jaguar Schematics is a must.


Doug:


well, you mentio0ned missing SIII's! So, you apparently did something about it and have two of them, one I6, and the other a V12. Twice the fun, huh!!


Carl

 

Yup, I'm returning to my roots, so to speak. After 137,000 miles of use I sold the XJR. It was a great car but I've sorely missed Series III ownership.

Cheers
DD