Well I have been working on my newly acquired 2000 S-Type and in the process I noticed that when I turn the left turn signal on it works fine when I turn the right turn signal on it will laminate both the left and right turn lights and backup lights dimly. Any suggestions on what to check first?

 

Gus, check with our forum certified jag tech: "Brutal". Off the cuff guess is that it may be an electrical module issue???

 

The front turn signal bulbs/sockets are bad about melting the electrical connectors and causing all sorts of faults. They are the 'plug-in' amber bulbs with the folded wires so check them first.

bob gauff

 

And look at any grounds, then any shared wires and lastly any wires that may be chafed..

 

I took a little time to look into the turn signal problem and this is what I did and did not find. With the left turn signal on it works just fine when I do the right turn signal the right turn light and both backup lights go off and on at the same time. Also the rear plate lights go off and on as the blinker works. I should mention that both front lights work fine. I pulled the right and left rear plugs and attempted to identify the ground. I am certain I have a bad ground because it is trying to find the ground and going to the other side and using the bulbs to get to it. With the power off measuring the continuity from pin to ground I got the same readings on all pins with the exception of the center pin I will call #4. On the left I get a reading of 047 (meter on 2000 Ohms Resistance) and the one on the right I get zip no change. No association to ground. The wire color code is Black with Green line. The oneline has not satisfied me to install a ground and wanted to see what I get as feedback from others.

 

Gus, heres the reponse to your PM, I an currently dealing with 2 Stypes doing the (for the most part) same thing. I have tried to jump from 1 side to the other with a ground since the lights are HOT all the time and the rear electronic control module provides the ground for operation. I suspect that your and my cars are suffering from a faulty rear electronic control module. 1 of the things about being at a dealer is the abilty to "borrow" parts to isolate issues during diag. ie sub in a known good unit. Just short cuts alot of diag time. So far on mine I have isolated it down to the RECM without the ability to swap parts(sunday work) arghhhh alot of pinouts there are a few issues on Stype lighting issues
1) blown fuse which causes feedback so check them
2) bad diode pack again causes feed back
3) bad circuit board for the tail light assembly ( pin the whole board if in doubt for continuity)
4) Bad rear electronic control module, this is the 2nd most likely issue if fuses are good(IMO)

 

I was going to check two things but did not get a chance to get on it today. I see that it has 2 grounding points in the rear one on the left “RA8” and on the right “CA156” and that is at the RECM (Rear Electronic Control Module). I did get a chance to check the left ground and it appeared to be intact. The one on the right I did not find to check. The lights obtaining the ground through the RECM so I want to check the plug if any associated with it but where is it?? You mentioned the Diode pack and I think I found them on the left at the wiring harness. Not sure how to test other than swapping. Let me ask you this, what if I was to make a isolated ground to the light housing?

 

I tried a isolated ground today, both bed of nails with original intact circuit, and severed. Both led to back feed and other lighting issues. at that point I gave up trying to "RIG IT"

 

Brutal,
Is this the control module that is under the fuse box? If it is, it not only controls the lights but it controls the security system. And the location is subject to moisture from the standing water problem the S-Type has in the trunk, so I was told!!! I was also told that if the wrong bulbs were installed it would cause a problem with the lighting system similar to the problem I am experiencing, so I was told! I will check this when I get home but wanted to let you know the information I got.

 

The standing water problem is often not as bad as standing water.... but any water means there's a leak as the trunk (boot) should be dry all the time. Either way, it can cause nightmare trouble with the module (REM) you mention.

 

Yes I know! The nightmare has begun!!!

 

Brutal you were right on. I went out this morning to find and fix the problem, tools in hand voltmeters the car onelines a cup of coffee and ready to go. First on my list was check the fuses but not with a volt meter and not in the car. I pulled the fuse and found it was blown. Of course this was the only thing I did not have so I was off to AutoZone. Replaced the fuse and I was on the road again. Thanks Brutal!

 

I have an 02 S-type 3.0 and it's having the same problem. I checked the fuses in the luggage compartment and none of them were blown. Any ideas? It's the rear right turn signal. It's doing the same thing as what Gus was describing. Also, when I apply the brake, I get the "right rear brake light failed" message at times.

 

Remove the fuse and check it removed or replace it.

 

Bad / high impedance somewhere (ground?) may be a possibility.

 

I removed the fuse that corresponds to the right turn signal. Not blown. Could it.be an recm issue? Where is the recm?

 

It could be but it's not very likely. In the boot (trunk).

 

This is a link to onelines for your car. I see that I have 2 for the 2002 year car, well either one should give you the location of the plugs and control units. See if this helps.

http://www.gusglikas.com/AutoRepairElectrical.htm

 

I have ordered an recm and it should arrive today. It came from a 2001 Jag s-type. Mine is a 2002 model s-type. The model number for the part that starts with yw4t..... is exactly the same. Will I need to program the recm to make it work with my 02 model? Also, are there any special precautions that I need to adhere to when replacing the recm? Thanks.