Hi Guys

Hope someone could help me…

my s-type 2002 2.5 v6 has a right tail light issue
the right signal is dimmed flashing with the reverse light on the right side also plate light is flashing and left-hand signal the reverse light on the right hand, when car reverse is not working when took the bulb of
the reverse out all flashing lights stopped but still no right signal

have checked the fuse changed the rear ECM got the same issue
on the rear light RHS the cluster connector I tested found that pins 1, 4 and 6 has volts of 11.30…
of the LHS I have checked found only 2 PINS 2, 6 on the connector has volts of 11.30 (All works fine)

Iḿ really confused the diagram of 2002.5 mentions that only 2 pins on each side should come from some relays …

Mag

 

HI
The rear lights are wired different to most cars
they use a permanent feed 12 volts to one side of the bulbs and the other side goes to the rear module which switches the negative to bring the bulb on
there is also 2, 12 volt feeds to each rear light, so 4 fuses in total for the rear lights
cheers
Joe.

 

I agree, only two pins (#2 and #6) on each side should have power. I'm totally confused how you're able to get power showing on pin #1 on the misbehaving right side.

Were those voltage readings taken with the plug disconnected? Or were you able to backprobe the connector while still installed? If measured with the plug still installed, you may have a bulb that is shorted across, at least one of the two bulbs labeled "tail". That's the only way I can see getting a voltage reading at pin #1.

Also, that 11.3v you measured seems very low. At that value, your battery is pretty much dead. The rear lights are powered via different circuits and fuses, so I don't think any one fault there could cause that. I'd highly suggest putting a charger on your battery to make your troubleshooting easier. Who knows, maybe some module is acting up with low voltage.

Also, some history may help with the troubleshooting. When did you first notice this problem? Are you getting any bulb failure messages on the dash? Any other recent work? Your favorite color?

 

Hi Eric


Thank you for your help
Finally I got the reason.. pin 2 has an issue and no power on that pin, when I have checked that I should disconnect the left-hand connector to left tail light to get the correct pin assignment on the right connector, when disconnected only power was present on pin 6 I have a bridge between 6 & 2 all works fine,

Now another question where is that power cut layin fuse 48 is OK ?? Is it OK to bridge these 2 pins (2, 6) ??

Regards
Mag

 

Thank you Joe

you gave me an idea to disconnect LHS connector

Cheers
Mag

 

Hi Guys

Does anyone know where is CAS5 connection point located? seems the issue there

 

You need to make sure two eliment bulbs are the correct type. Fitting the wrong bulb, ie wrong pins and contacts, will cause a short between two of the lamp circuits and it will give you some strange effects like the ones you have been getting.
Mellow

 

Mag,

I'm having trouble following all of this. Let me make sure I understand something correctly. Previously you had said you were getting power at pin #1 on the righthand side (that pin should not have power). I've seen no more mention of this. Was this resolved? Did you have your meter lead at the wrong spot?

Next you've said you found no power to pin #2 (should have power), and this was at the righthand side? Meanwhile, pin #6 (at the same right side connector) has power as normal? When you connected a jumper wire between pins #2 and #6, everything worked?








Before diving in too deeply, let's consider splice CAS5. It gets power via fuse F48 in the Rear Power Distribution Box. At splice CAS5, this wire now branches off to four circuits. Note the circled labels 75S, 76S, 77S, and 78S at the right side of the diagram, which lead to figure 08.3.

It appears the wire labeled 75S is your problem, as it feeds directly to pin #2 at the righthand rear light assembly. This is the pin you said had no power, leading us to believe you've got a broken wire between those points, or the wire has pulled loose from the splice. However, do the other three circuits downstream of splice CAS5 (labeled 76S, 77S, and 78S) all work properly without the jumper? If not, the problem is likely to be the power supply to splice CAS5, as it feeds all four circuits.

76S = Right side marker light. I believe this light is on the side of the rear fender, separate from the main rear light assembly.

77S = Left license plate light.

78S = Right license plate light.


Just to avoid any confusion, those labels (75S-78S) are only used on the wiring diagram to take you to another page. Those aren't the official labels for the wires themselves.

Anyways, please let us know about those other three circuits fed via splice CAS5. I've no idea of the splice's specific location, but judging by the wiring diagram, it will be located between the Rear Power Distribution Box and the right tail lamp unit.

 

Excellent point! For troubleshooting, you can swap the known-good bulbs from the left side to the right and see what happens.

 

Hi
you are correct,
when I got the measures for the first time with the LHD connector connected the LHD got different pins with 11.... volts , PIN #2 has no power, then disconnected LHS on RHS only PIN #6 has power then realized that Pin #2 has the issue
I have ordered a cable tracer hope this helps, as don't want to take whole wires off the sleeves.

Once get the tracer will let you know what I have found.

Regards,
Mag

 

And what about those other three lights I mentioned? The two above the license plate, and the third on the outside of the right rear fender? Are they working with the jumper removed? Those three lights get power through that same splice. That will be a big clue.

FWIW, I highly doubt there's a problem at the splice. It's a factory crimp, well protected inside the harness.

 

Any progress? Specifically, what about those other three lights fed by the same power source? Are they working? This is a huge clue to help determine how best to continue troubleshooting.

One possibility is that one of these bulbs is drawing excess current and pulling down the available voltage. It's not quite bad enough to blow the fuse, but just enough to keep the other bulbs on the same circuit from operating properly.

Also, you never answered whether or not you were getting any bulb failure messages on the dash.

 

Yes sure will post test result after recovering from the nightmare I have got with that bridge I have done between pin 2 and 6 it drained the battery there is a short there
I have noticed that Right side mark is not working will test lines from fuse 48 to the 4 ends 75 76 77 and 79


And will let you know.

 

Try removing that bulb and see what happens.

Think of simple stuff. Damage to the wiring is not very likely. Not impossible, but not very probable. Most of it is very well protected. (One exception is the part feeding the license plate lights, as that flexes back and forth at the trunk lid hinge.) Certainly check the wiring, but don't get fixated on a wiring fault being the only possible cause.

A bulb shorting out? Not far-fetched at all. The wires feeding each bulb are typically only heavy enough to handle normal current flow. A manufacturer won't spend more money than needed, so the smallest suitable wire size is typically used. If a bulb shorts out, it tries to draw too much current, but is limited by that small upstream wiring. The end result is low voltage near the ends of the circuit, possibly including other branches, but the fuse doesn't blow. Sounds odd, but I have encountered this many times, especially with bulbs.

Removing the bulb and checking the socket for voltage in such a situation can be VERY misleading. A meter draws such a tiny amount of current, it easily passes through the wiring and shows full voltage available. So voltage checks in an unloaded circuit are helpful, but are not conclusive. Don't fall into that trap, either. I do not care to discuss how I know this...

 

@kr98664 I intended to take the car to the Jag garage today but when I saw the harness how it's clean and neat and no any sign of damage or rust will give myself another chance don't need to open the harness actually

M

 

Any update? The suspense is killing me!

 

Found the criminal is the line from rear fuse box 48 to pin no 2 on rear left tail light seems wire is broken ran an other test wire directly and right indicator works fine
I ordered a cable tracer will get it by Tuesday if not get where line is broken will run a new line
NB. I have checked the right connector again no power except 2 and 6 also no shorts

What are your thoughts guys.

Mag

 

Nice work!

Rather than tear the trunk apart trying to find the broken wire inside the harness, I'd be tempted to just run a new wire parallel to the harness.

 

Will have a new experience with the cable tracer and see what I will get as I already identified the Brown-white cables to the right rear light
need to get the broken position hope get that ...

 

I got to thinking about this a little more. Did you actually confirm a broken wire by checking end to end with an ohmmeter? Or are you just extrapolating this because the system behaved with a test jumper?

Also, did you ever try removing that side marker bulb as previously suggested? I see no mention of that, so want to be sure. Please see my previous comments of how a shorted bulb can draw down the available voltage for the rest of a circuit, yet not blow the fuse.