75ZT Community

Took out LCM and disconnected, could find no evidence of corrosion or similar. Considering buying second hand LCM over internet. Any potential issues here with compatability when installing. Have included photo of a earth connection in motor. Is this correct as cannot fins any photos to confirm Regards Jeffrey

The LSM (Light Switch Module) contains info that matches it to the IPK (Instrument pack (IPK from the German)) so not a case of just taking one out and putting another in

Thanks Paul. My error yes LSM not LCM. So it is not that simple it appears. So what is the process to match the LSM with the IPK. Do the codes on my current LSM assist in any way?

To match the lightswitch to the car, needs a T4 (Testbook version 4.Computer Diagnostic System). I don't think you can use a second hand one either, though there may be ways to reset them so you can. But I would see if you can borrow one just to try it out as even though you would see an error, the lights would work OK if its the source of your problems.

You are right, the connections do look OK. Its worth checking you have got power at the connector in the two largest pins. You will need something thin and flat to push into the holes on the connector.

The earth wires will be connected at the bottom of the drivers A pillar inside the car, just behind the panel where the bonnet release is.

My local Rover guy has lent his T4 to someone in Melbourne. It may not be back until after Christmas so looks like I will have to wait.

Jeffrey.
Did you take a look at the front drivers side wiring chaffing on the chassis, under the light ? bumper off job or at least let it hang down so you can get access remove the light and check the wiring

I was considering disconnecting the battery to see if that created any sort of reset. Any opinions on this course of action?

Jeffrey wrote:I was considering disconnecting the battery to see if that created any sort of reset. Any opinions on this course of action?

It won't do any harm, but is very unlikely to fix it. Worth a try since its free.

Hi Artic. Saw your note on the wiring. Have checked most wirings but will check out both drivers and passenger side lights. Cheers.

At last a result!! I decided to leave my car in my fully enclosed garage over Christmas for 2 weeks. Here in Queensland it is summer, some humidity but most days around 30deg Celsius. Anyway did not touch the Rover for at least 12 days. Went to start it yesterday but flat battery was the problem. Now running and all lights, brake lights, instrument panel,indicators that were a problem are now working again. Can only assume I had a moisture problem somewhere which dries out over the 12 days plus created some drain on the battery. Have had a good look over the tourer body etc but cannot seem to see any areas of potential water getting in??? I will comment that I had the engine belly pan removed 6 months ago ( still off ) due to loose screws and lack of replacements. Any ideas of possible water entry points?? and would my summary of events seen logical? Could the removal of the belly pan be a potential problem for water getting to electrical areas?? Previous comments greatly appreciated and welcome more re this post. Happy New Year. Here today 32dec Celsius New Years Eve night will drop to about 23deg Celsius. So plenty of outdoor parties around here tonight.

Glad you have the problem sorted but please spare a thought for those of us in the UK - we replace your Celsius with Fahrenheit

Thanks for your comments. Unfortunately the problem has returned???. All was good for one day, have had no rain and drove the car for about 100kms. Checked it in the garage last night again all was good. Checked again in the morning and the exact same problem has returned!!! Complete mystery to me but I suspect something to do with the high rear brake light in the rear window of the tourer. Looks like a T4 analysis required when my Rover mechanic comes back from his Christmas break.

beginning to look more like a wiring fault (Bad earth) or faulty LSM....

Downloaded the Rover 75 Body Electrics workbook ( thanks to this web site ) Interesting when you analyse where the problems are. They follow the same circuit back to fuse 9 under bonnet and are located with consecutive pins on the LSM. Fuse seems okay so off to the auto electrics with my diagrams etc and see what happens. I also am suspecting a faulty LSM which is a pain to replace me thinks.

Jeffrey wrote:Downloaded the Rover 75 Body Electrics workbook ( thanks to this web site ) Interesting when you analyse where the problems are. They follow the same circuit back to fuse 9 under bonnet and are located with consecutive pins on the LSM. Fuse seems okay so off to the auto electrics with my diagrams etc and see what happens. I also am suspecting a faulty LSM which is a pain to replace me thinks.

Yes, that's why I suspected one of the main feeds, and even though the fuse is OK its worth checking the feed actually at the LSM. In other words, is the feed from fuse 9 actually getting to the LSM?

It might also be worth checking the plug underneath the under bonnet fusebox that connects the feed from fuse 9.

Problem is finally resolved. Was apparently faulty connections either going into or out of the under bonnet fuse box. Box was removed and all connections cleaned and re connected. All lights back working for the last two days so assume problem now fixed. Auto electrician said this can be a common problem with Rover 75's. Thanks to all previous comments on this topic.

Interesting that he says its common. Only heard of a similar failure once. Glad its solved.

Perhaps he only deals with Jeffreys car

I have virtually the same symptoms and have unplugged the UBH and tried a replacement LSM. Thanks for the pointer - will be taking the fuse box out next weekend to check connections. I've lost one headlight, both tail lights, one front and one rear indicator, all dash illumination, but still got brake lights.