Rear fog lights

[bogart]

Before wiring my own arrangement I thought I would give it another chance. Well I think I'm losing it big time. The fog lamp is part of a 21/4W lamp, with the fog lamo being the 21W bit and the 4W being some parking/running thing.
Well what I've found is that the 21W section is on all the time ie quite bright. Ive checked the lamps over ie smallest resistance equals greatest power and should connect with the foglight 12V which is a pink wire. Well it doesn't its connected to the green wire which is this running/park thing.
Could somebody possibly have a look ant theirs to see if I am crackinh up. This lampholder is cream in colour and the handle is not flat but domed. Does you dome point upwards or downwards.
Mind you ive still no 12V on the pink wire which according to Haynes is the foglight feed.

[bogart]

Me thinks I may be there. Lampholder fitted with dome to bottom. Fogs now work and only 4W lamp comes on. These lampholders must be a bit dodgy and easy to fit incorrectly.
I managed to fit one the wrong way round and the fog lights came on when switch set to off, explain that!
The fitting of the lampholder in the socket is not idiot proof as I have proved.
Somewhere along the line what with changing relays etc I managed to blow the 10A fuse. Replaced and touch wood all ok at present.
Have till end of business on Monday to get it back for a free test of the failed lamps.

[bogart]

I knew if I opened my gob it would all go wrong. After assuming all ok I was flashed a few times beacuse the nearside fog lamp was on continually.
Status so far is off side fine. 4W and 21W behave as they should. Mind you I,m still wondering why there are 2 lamps above one another 5w above the 4W element.

Now if I put the nearside lamp into the offside holder only the 4W lights no fog. If I put the offside lamp and holder into the nearside the 4W is on all the time. And if I put the nearside lamp into the offside holder in the offside we get the 21W all the time.
I buggared if I understand that either.

[Bernard333]

I think I have figured out what the shunt does , when the REM energises the fog relay it puts 12V on the pink wire and the lamp comes on but when its not energised its connected to the middle of the shunt so there will always be a voltage accross the bulb itself but the shunt provides a much lower test voltage . This enables the REM to constantly check that your rear fog lamp bulb is working even when its not switched on , could be completely wrong but cant think of any other use for it .

[overwoody]

I had a near failure on similar grounds, but I politely went to the light switch and turned them on (many inspectors forget that even in the off positions daytime running lights are on, but fogs etc dont work in most circumstances).

Im sure this is not the same in your case.....

[bogart]

Well here is another good one. Spent yesterday evening getting nowhere and cointinued this morning. Grasping at straws I checked the lamps and lo and behold they differ even though supposed to be the same. Its as if the base on one has been turned through 180 deg. Manufacturing fault me thinks. Anyway with two same bulbs I now get the following scenario.

Either lampholder with either lamp works ok in the offside ie running light then fog when switch depressed.

Nearside I get running light with either lampholder or lamp, but no fog lamp. Now the assembley that the lamps plug into is different from each side. I had made the assumption that they were the same, but no.
Now as expecetd if I use the 180 deg out lamp in that holder I get fogs all the time.
Am going to pack in and take it for its retest tomorrow.
As the offside fog lights and both running lamps work its good enough for me and should satisfy the tester as the MOT only requires a working offside foglamp.

Hope you understood some of that.

[JMCA-S60]

Originally Posted by bogart

Either lampholder with either lamp works ok in the offside ie running light then fog when switch depressed. Nearside I get running light with either lampholder or lamp, but no fog lamp.

This is perfectly normal functionality. V70's come from the factory with only one working rear fog lamp. In this country that is the offside. The nearside must be modified to make it work!
Searching the forums for "rear fog lamps" or similar will reveal more information!
Sorry I was late reading this thread, but glad you sorted it!

[bogart]

Well finally got the MOT certificate. What was throwing me was the replacement lamp I used has been manufactured incorrectly. The pin outs are reversed, probably made in China!

Thanks to everyone for their time and effort, much appreciated.

[henrycrun]

Not wishing to start another thread on this, can we confirm that a UK P2 V70 (yr 2000) has 1 or 2 rear foglights as standard ?

I can only get my RHS one to light up.
The LHS one has a 21/5 watt bulb fitted, and yes I have tried another bulb.
Thanks in advance.

[A lex]

Originally Posted by henrycrun

Not wishing to start another thread on this, can we confirm that a UK P2 V70 (yr 2000) has 1 or 2 rear foglights as standard ?

I can only get my RHS one to light up.
The LHS one has a 21/5 watt bulb fitted, and yes I have tried another bulb.
Thanks in advance.

One only.

For the UK market Volvo purposefully disabled the LHS lamp - to get it working again you have to solder a bit of wire over the broken track in the lights circuit board. A search should throw up a thread or two.