Mystery??

[clf]

In this instance I would urge you to pull out the LSM and check it. There is one instance I recall of a 75 catching fire on the road with the source stated to be the LSM, and they are known to corrode (visible through the casing).

To check the wiring in my picture above, you really need to remove the bumper and headlight, but you may be able to feel if the wiring is damaged by sliding your hand between the headlight and the chassis leg. But this will likely only result in a failed bulb.

[slovcan]

Originally Posted by Caulkhead

No t4 on the Isle of Wight, as I said all is well today, so hopefully car will continue to be reliable, on 175k now, so would have to retire it if any problem that proves to difficult to sort. Fingers crossed that whatever happened won’t happen again.

Hi Roy,

I suspected that might be the case. I was thinking about if you ever got to the mainland with your car it would be good to get the LSM checked and a general health check. Having read CLF's post, I would do as he suggests just to ease concerns of impending more serious problems. The LSM is married to a bunch of car systems and information, so does need a T4 involved if it must be replaced. That said, maybe a replacement LSM could be configured by someone like MarinaBrian for you if he had your VIN, indicated mileage and like information from your car.

As to the other remarks, I'm not convinced they were meant to be mean spirited, but sometimes comments meant to be humourous lose something in the translation when they are posted on the internet. Sometimes emojis ought to be given greater consideration regarding their meaning as well. I hope so, anyway.

Cheers,
Glenn

[Caulkhead]

Thanks for the further advice about the LSM. I really don’t know what it is or what I am looking for. If the lights coming on was due to a fault with this LSM would it not occur again, it seems to me the only thing different to how I usually leave the car is the key was in the ignition. As yet the problem has not reappeared, and all electrics are working as they should. Do you really think that I should take all the front off? What would I then be looking for. I am disturbed to hear of instances of fire, is this likely to happen? His many 75’s have had this happen. Should I lay the car up or even get it taken for scrap? Clearly don’t want to risk a fire. Taking the car to the mainland is not a realistic option for all sorts of reasons, but do the experts really think that I am in danger using this car, which has run well for the last two days, with no issue. I welcome further thoughts. Thanks

[slovcan]

Originally Posted by Caulkhead

Thanks for the further advice about the LSM. I really don’t know what it is or what I am looking for. If the lights coming on was due to a fault with this LSM would it not occur again, it seems to me the only thing different to how I usually leave the car is the key was in the ignition. As yet the problem has not reappeared, and all electrics are working as they should. Do you really think that I should take all the front off? What would I then be looking for. I am disturbed to hear of instances of fire, is this likely to happen? His many 75’s have had this happen. Should I lay the car up or even get it taken for scrap? Clearly don’t want to risk a fire. Taking the car to the mainland is not a realistic option for all sorts of reasons, but do the experts really think that I am in danger using this car, which has run well for the last two days, with no issue. I welcome further thoughts. Thanks

Hi Roy,

The LSM is the Light Switch Module. It is right behind the headlight switch knob. Just keep an eye on it to be sure your lights are all off when you park the car. Also, have a look at the headlight switch after dark sometimes to see if the switch itself is not illuminated. If nothing ever happens again don't worry about it, but monitor it.

The talk about removing the front bumper was to do with the headlight wiring harness rubbing on the top unprotected seam of the front "frame" rail (chassis). It is hard to to access that spot and removing the bumper makes that easier. You may be able to root around to see if the harness looks OK or looks damaged there. BUT, to be honest, if your headlights both work reliably you probably don't have a problem there.

I expect there would be some pretty obvious signs before anything got to the point of catching fire. If you watch the things I mentioned and your headlights work, drive on.

That is what I would do. Others may not agree, but that's what I would do anyway.

Cheers,
Glenn

[clf]

Originally Posted by Caulkhead

Thanks for the further advice about the LSM. I really don’t know what it is or what I am looking for. If the lights coming on was due to a fault with this LSM would it not occur again, it seems to me the only thing different to how I usually leave the car is the key was in the ignition. As yet the problem has not reappeared, and all electrics are working as they should. Do you really think that I should take all the front off? What would I then be looking for. I am disturbed to hear of instances of fire, is this likely to happen? His many 75’s have had this happen. Should I lay the car up or even get it taken for scrap? Clearly don’t want to risk a fire. Taking the car to the mainland is not a realistic option for all sorts of reasons, but do the experts really think that I am in danger using this car, which has run well for the last two days, with no issue. I welcome further thoughts. Thanks

I am sorry for scaring you, it was not my intention, but was meant to encourage you to check it out, OK maybe a little bit because it is relatively simple to check. LSM (light switch module) - I cannot remember how to remove exactly, but panel that surrounds it, is held in with clips and maybe a couple of screws, and if I recall quite obvious when you look. Once removed, that reveals the screws which hold in the LSM. Once they are unscrewed it can be pulled forward, at which point you could look into it, and at the wiring plug, to verify any corrosion. If all looks clean, great, it will be obvious if it is bad, then refitting is reversal of removal.

To check the wiring under the headlight properly, you would really need to remove the light units, ie bumper off (although I have removed the lights by just undoing the top bolts and easing it forward carefully). But as I said before, you may be able to slide your hand under the headlight unit and feel for the loom as it runs over the chassis legs, feeling for damage.

It could indeed be an intermittent issue. Moisture in the air getting to existing corrosion at the lsm wiring causing it to swell a little further, maybe contracting as it dries. I have not experienced it (corroded plug on the LSM) personally, but others have and would wager it started as an intermittent problem for some.

The wiring issue over the chassis leg was randomly intermittent shortly after I got my car. Showing a failed sidelight bulb once in a while. Then becoming more common when going over a bump, finally becoming permanent.

I am not saying this is your issue, however they should be relatively easy things to eliminate and even to rectify if necessary. Certainly not issues to abandon the car

[Mike Noc]

Originally Posted by Caulkhead

No t4 on the Isle of Wight, as I said all is well today, so hopefully car will continue to be reliable, on 175k now, so would have to retire it if any problem that proves to difficult to sort. Fingers crossed that whatever happened won’t happen again.

cb750chris has one, knows how to use it and is in Portsmouth -pretty much as local as it gets once you have set foot on North Island.

[marinabrian]

Roy, it's fairly easy to check the LSM (light switch module"

First remove the two self tappers securing the lower dash trim, hook your fingers under the leading edge, and pull it backwards to release the three clips securing it to the dashboard.

Now you will see the three screw securing the LSM, after these are removed, the LSM can be pulled out of the hole in the dash, leaving you with something looking like this ........



On the plug as the top, can be seen a "hinge", depress the tang in the centre, and this "hinge" rotates towards you, which will simultaneously unplug the connector.

Leaving you with this.......



The connector on the unit, and the plug, should be inspected for any sign of green corrosion, if present, now is the time to give the connector face a good scrub with isopropanol or some switch cleaner, similarly the connector on the LSM itself.

Finally, as you have it this far, it would pay to release the four tangs securing the switch fascia to the main LSM body, and slide out the circuit board to check for any obvious signs of distress, such as burning to the circuit board.

All of this at a leisurely pace, should take no more than an hour, it would take me as I have plenty of experience in pulling these apart, about 10 minutes tops.

Hope this is helpful

Brian

[COLVERT]

Originally Posted by Caulkhead

Thanks for the further advice about the LSM. I really don’t know what it is or what I am looking for. If the lights coming on was due to a fault with this LSM would it not occur again, it seems to me the only thing different to how I usually leave the car is the key was in the ignition. As yet the problem has not reappeared, and all electrics are working as they should. Do you really think that I should take all the front off? What would I then be looking for. I am disturbed to hear of instances of fire, is this likely to happen? His many 75’s have had this happen. Should I lay the car up or even get it taken for scrap? Clearly don’t want to risk a fire. Taking the car to the mainland is not a realistic option for all sorts of reasons, but do the experts really think that I am in danger using this car, which has run well for the last two days, with no issue. I welcome further thoughts. Thanks

As I said, when my LSM played up I took it out and noticed very slight corrosion on the socket pins. As this corrosion is usually the result of a trace of moisture getting in I sprayed the pins and the circuit board with a fine coating of WD 40.--This stops any further corrosion.

The LSM has been working well for several years now with no more problems.----


PS. Stop worrying about a fire. There are lots of things on cars that can cause a fire but very rarely do. Your car seems now to be behaving itself. I'm sure it will continue to do so.---

[Caulkhead]

Originally Posted by marinabrian

Roy, it's fairly easy to check the LSM (light switch module"

First remove the two self tappers securing the lower dash trim, hook your fingers under the leading edge, and pull it backwards to release the three clips securing it to the dashboard.

Now you will see the three screw securing the LSM, after these are removed, the LSM can be pulled out of the hole in the dash, leaving you with something looking like this ........



On the plug as the top, can be seen a "hinge", depress the tang in the centre, and this "hinge" rotates towards you, which will simultaneously unplug the connector.

Leaving you with this.......



The connector on the unit, and the plug, should be inspected for any sign of green corrosion, if present, now is the time to give the connector face a good scrub with isopropanol or some switch cleaner, similarly the connector on the LSM itself.

Finally, as you have it this far, it would pay to release the four tangs securing the switch fascia to the main LSM body, and slide out the circuit board to check for any obvious signs of distress, such as burning to the circuit board.

All of this at a leisurely pace, should take no more than an hour, it would take me as I have plenty of experience in pulling these apart, about 10 minutes tops.

Hope this is helpful

Brian

I will hook it out at my earliest opportunity and look at it for signs of damp etc. If it looks dodgy and best replaced what will I need to do to the replacement to get it to work - reprogramming? Also where are the replacements available? Thanks To all for further advice, hope it’s not tempting fate but car is starting and running great.

[alanaslan]

Originally Posted by Caulkhead

Before putting members down why not realise that some of us love these cars but rely on advice from members who have skill and knowledge. My tourer is a 51 plate. It cost me £750 5 years ago, it has passed mot each year without major issues, the bodywork is sound, I get oil and fluids changed regularly. I love driving around the Island with my dogs in the back and often have great conversations with admirers in car parks. I have on each occasion that I have had an issue with the car sought advice from the forum. French Mike, Arctic, Brian, Klarzy, Harry and others to numerous to mention. I have done the sunroof drains, the handbrake, the FBH, the brake discs and pads, those big round things on the suspension and changed the crankshaft pulley recently. I am nearly 70, I do not welcome members posting emojis that brand me as thick, stupid or duh!

As I said the car is at present running fine, access to t4 is not available, I listened to advice, but the car returned to normal running after 2 hours charge, I do not have a garage full of testers, so cannot check it’s s condition. It either works or I get a new one. The remark that my fingers were crossed was not meant to be a technical comment, just that as at present all seems well, I hope the mystery lights on was just an unexplained event. If it happens again I will of course have to seek further advice and support. However, there is a limit to my budget, so fingers crossed that the car continues to be reliable and a joy to drive. My charger says the battery is fully charged and the car is starting and running fine. Cut out the smart ass put downs and judgemental conclusions about members less technically able or knowledgeable. Nice day here, hope all is well for all of you. Love this forum for support, don’t need to be judged or put down!

I know exactly where you are coming from like yourself I am of that wonderful age group. In the past I used to restore classic cars as a hobby that paid for the family house abroad.
I am lucky that I have a garage and a workshop but also have 55 years worth of tools collected in every nook and cranny.
One of my other hobbies was motor sport, which has seen me compete in the 60s and 70s on the track and in rally’s, I have also Marshalled for local car clubs, the FIA, and the ACO,
It has also been my privilege to crew for several teams at the Le-Mans 24 and other events across Europe and the UK.
Sadly now after breaking my back some years ago and the general onset of old age and all the joys that come with it, I find myself greatly restricted in what I am now able to do. This does not make me thick or stupid. It just means that I have had to learn my limitations. I love my Rovers and take a lot of stick for it now. Strange these people were the same people who were envious of my Launch night 75 conni Diesel with all the toys.
From one old man to another I wish you many more happy years of Rover driving, such quality and extras as standard in the top range models that are still up to date today.
Alan


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