terminal pins on LSM

freelancer · 7th May 2023, 14:48

trying to sort alleged rear o/s fog lamp bulb failure (but bulb is good); is there a "how to" on accessing LSM to clean terminal pins (if its gotten damp?)

xsport · 7th May 2023, 15:00

unless the Lsm shows signs of water ingress/giving rise to oxidation and discolour around that area .. its probably ok. you could however give the plug a clean with contact cleaner and work it in and out quite a few times to clean any bad contact surfaces, and check the wire crimp/solder connections at the terminals are good. If it has experienced water ingress due to sunroof non drainage your at the right place to start. Next destination would be the light unit itself looking for a bad connection.If you have a test meter you should be able to find the problem with either continuity or a bad earth. Just the weather for a few hours outside . !!

xsport · 7th May 2023, 15:07

if the light comes on and flickers , as mine did occasionally , it will throw a bulb out warning. This was on a rear parking light.Not sure if the circuit for the foglamps are also covered . When ever i got out to check it never revealed itself and was working as normal ! The eventual fault was traced to a plug connection which worked itself out a little over time. job sorted with a little cellatape. happy days !

freelancer · 8th May 2023, 13:43

tks xsport.

Took off cover and then three screws around light switch to access lsm. Took off plug on lsm (white bar move forwards) and cleaned both parts of plug with contact cleaner a couple of times.

Alas, rear fog o/s bulb failure as before...
Unless a run with the car makes fault disappear...

vitesse · 8th May 2023, 15:49

Open the LSM again and check for power on pin 47 (U/W wire RH rear) and pin 49 (U/Y wire LH rear) both as I still haven't a clue which side o/s is, hint: your off side isn't the same as my off side but RH and LH is the same for both of us.

I hope the information is correct, otherwise someone will correct me.

Good luck

bl52krz · 8th May 2023, 16:28

Have you tried out cleaning the bulb holder inside, with some emery paper? Had mine play up when in Germany, so took bulb out and did that and all was ok. Still is. White residue inside the holder was the culprit.

freelancer · 9th May 2023, 12:48

Had another go at bulb-holder end of R/H tail assembly where rear fog light bulb sits.
Two things:
(i) wire leads running into the plug at the back of the assembly have been "tampered" with at sometime in the past as they show where they have been cut into....(grafting in some towbar light/electrics perhaps?...). Bit worrying, anyway gave a good spray with contact cleaner.
(ii) 6-pin pug at back of lamp assembly I'd missed before so gave a gentle scrape with emeryand a good sorting with contact cleaner.

Whether (i) or (ii) or a bit of both, - working again!!!

Thanks for advice and support!

7th May 2023, 14:48	#1
freelancer Avid contributor Rover 75 Saloon Connoisseur SE 2.5V6 Join Date: Oct 2011 Location: Aberdeen Posts: 226 Thanks: 56 Thanked 12 Times in 11 Posts	terminal pins on LSM trying to sort alleged rear o/s fog lamp bulb failure (but bulb is good); is there a "how to" on accessing LSM to clean terminal pins (if its gotten damp?)

7th May 2023, 15:00	#2
xsport Posted a thing or two rover 75 club se Join Date: Apr 2011 Location: Leicester Posts: 1,660 Thanks: 358 Thanked 419 Times in 310 Posts	unless the Lsm shows signs of water ingress/giving rise to oxidation and discolour around that area .. its probably ok. you could however give the plug a clean with contact cleaner and work it in and out quite a few times to clean any bad contact surfaces, and check the wire crimp/solder connections at the terminals are good. If it has experienced water ingress due to sunroof non drainage your at the right place to start. Next destination would be the light unit itself looking for a bad connection.If you have a test meter you should be able to find the problem with either continuity or a bad earth. Just the weather for a few hours outside . !! Last edited by xsport; 7th May 2023 at 15:08..

7th May 2023, 15:07	#3
xsport Posted a thing or two rover 75 club se Join Date: Apr 2011 Location: Leicester Posts: 1,660 Thanks: 358 Thanked 419 Times in 310 Posts	if the light comes on and flickers , as mine did occasionally , it will throw a bulb out warning. This was on a rear parking light.Not sure if the circuit for the foglamps are also covered . When ever i got out to check it never revealed itself and was working as normal ! The eventual fault was traced to a plug connection which worked itself out a little over time. job sorted with a little cellatape. happy days ! Last edited by xsport; 7th May 2023 at 15:12..

8th May 2023, 16:28	#6
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,394 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	Have you tried out cleaning the bulb holder inside, with some emery paper? Had mine play up when in Germany, so took bulb out and did that and all was ok. Still is. White residue inside the holder was the culprit. __________________ Great Barr, Birmingham.

8th May 2023, 13:43	#4
freelancer Avid contributor Rover 75 Saloon Connoisseur SE 2.5V6 Join Date: Oct 2011 Location: Aberdeen Posts: 226 Thanks: 56 Thanked 12 Times in 11 Posts	tks xsport. Took off cover and then three screws around light switch to access lsm. Took off plug on lsm (white bar move forwards) and cleaned both parts of plug with contact cleaner a couple of times. Alas, rear fog o/s bulb failure as before... Unless a run with the car makes fault disappear...

8th May 2023, 15:49	#5
vitesse I really should get out more....... Rover 75 Saloon Join Date: Jul 2011 Location: Gävle Posts: 2,537 Thanks: 395 Thanked 823 Times in 652 Posts	Open the LSM again and check for power on pin 47 (U/W wire RH rear) and pin 49 (U/Y wire LH rear) both as I still haven't a clue which side o/s is, hint: your off side isn't the same as my off side but RH and LH is the same for both of us. I hope the information is correct, otherwise someone will correct me. Good luck

9th May 2023, 12:48	#7
freelancer Avid contributor Rover 75 Saloon Connoisseur SE 2.5V6 Join Date: Oct 2011 Location: Aberdeen Posts: 226 Thanks: 56 Thanked 12 Times in 11 Posts	Had another go at bulb-holder end of R/H tail assembly where rear fog light bulb sits. Two things: (i) wire leads running into the plug at the back of the assembly have been "tampered" with at sometime in the past as they show where they have been cut into....(grafting in some towbar light/electrics perhaps?...). Bit worrying, anyway gave a good spray with contact cleaner. (ii) 6-pin pug at back of lamp assembly I'd missed before so gave a gentle scrape with emeryand a good sorting with contact cleaner. Whether (i) or (ii) or a bit of both, - working again!!! Thanks for advice and support!