Rear lamp relay module

Well I found the light problem! Does any one know the value of R9? Too burnt to be read and I would prefer not removing the otherside at this time.

another pic

David …

Congratulation on your first Bulb Failure Module repair and welcome to your new part time job !!

Thanks. I needed a hobby, but not a career!

Greetings I am new-b to forum I have left rear module problem and I assume many more to come.
Regards,

Fletch … Welcome to the team !!

Some folks never have a problem with this system … sigh … but many others of us have been plagued with it for years. Sometimes the “bulb” warning light on the VCM comes on and stays on, sometimes it comes on for a little while and then goes out (and maybe comes back on , who knows), and sometimes it just momentarily flashes on.

First you need to check all your exterior lights and I mean really check them because they may be working but drawing to much or not enough current and you’ll still get the VCM warning. If that isn’t your problem then it’s probably a faulty module.

Of course if you’re a purist and want to keep everything original then you can replace all 4 modules with new ones for about $500 a piece … OUCH. Or maybe you can determine which module is faulty and just replace that one … smaller OUCH. Or-r-r you can get a used module and roll the dice that it’s any good.

But lets say you’re really talented and you want to track down and repair the problem in the module yourself (almost assuredly it’s a bad solder joint). Take a look again at David’s picture of the module’s innards, wow that’s a LOT of solder joints.

Your other option is to bypass this unbelievably overcomplicated system with an easy work around. Total cost about $.02 for a short piece of wire. You’ll never have that &%#$ light again.

After owning my Jag for 25 years and having to look at that dreaded light on and off for about 23 of them ask me which option I finally settled on :grin:

Great send me the wire . or tell me where to paste, just tell me…
Basic idiot as it would pertain to modules.
With Regards,

Fletch …

The “hack” on the bulb failure warning system simply involves soldering in a short length of jumper wire in the rear of the instrument cluster. Nothing special about the wire, car speaker wire would work just fine, basically anything you have laying around … Hey you just saved yourself that $.02 !! You’ll permanently disable the bulb monitoring system and the dreaded “bulb failure” warning light on the VCM will never again appear. So you’re back to checking for burned out exterior lights the old fashion way. If it was good enough for my Grandpappy it’s good enough for me.

You’ll need to remove the instrument cluster which is a little involved but nothing complicated. plan on an hour or two for the whole project.

If this is something you want to do let us know and we can provide you with step by step (with pictures even) instructions.

Welcome to the group I had to pull the right module to try to find a proper value but that one seams to be going as well! Hopefully with all the help and info here I will get !

Greetings: I would hope that collectively we can reduce the complexity of these modules . I have sent mine to a rebuild module outfit, and I will report how good they are.

I did not want to swap one good Right for a failed Left, FYI

their is continuity from several pins on the good one and non on the failed unit.

Fletch …

You posted “I would hope that collectively we can reduce the complexity of these modules”.

Let me say that in the past a lot of us have spent a lot of time and effort dealing with this problem.
With this system you only have 2 options.

  1. Make sure that every exterior light bulb connection is nice and clean with no corrosion or oxidation.
    And deal with any bad solder connections within the modules, after you first determine which
    module has the problem. Remember when you open the module a hairline failed solder joint is
    almost impossible to see with the naked eye. I’ve repaired modules (note the plural) over and over
    and sooner or later the problem always came back. VERY FRUSTRATING !

  2. Hack the system and eliminate the light completely.

There is no way to “simplify” this system.

Thank You…
Has any body hacked the system that has the process down?
Seems that a great deal of effort to interface VMS .
Again, Thank You

Fletch …

Several of us put our heads together a while back and came up with a fairly simple workaround. I know Jaguar Pete and I are very happy with the results.

Click on the magnifying icon at the top right of this page and type in …

  xj40 hacking the digital dash bulb failure modules

This will give you all the technical details of the system and how to get around it. If you go to Jaguar Pete’s photo album he has pictures of what you need to do once you remove the instrument cluster.

What magnifying icon?

If the relay module stops power to the light bulb what good is it just turning off the vcm?You still need power to the bulb?

Top right of page - looks like a magnifying glass followed by 3 horizontal bars and your logo

Exactly - What say you Dennis? :slight_smile:

You mean the search icon?

Yep, that is the one.

Thanks I just did that and reading it now, but as in my last post the goofy x is gone but my module is not sending power to the bulb whats the point?