Rear offside fog lamp not working - MOT fail

[940volvoman]

So Dave(Laird Scooby) says that the wire is in place for the nearside fog?

Am I understanding him right,especially as mine is one of the last Celebrations to roll off the production line?

If so I've wasted a good number of years waiting for the "right time" to run a cable from offside to nearside to feed an additional bulb.

In reality it make sense as these cars were also made for left handed drivers(Europe and beyond)

[taiwan740]

Originally Posted by Laird Scooby

Fix the rear fog and take it somewhere else for MoT - before you do, pop the cover off the 3rd brake light bulb, clean and tighten the connectors to the unit and on the bulb, refit and i reckon you'll have solved the problem as there is no relay for the 3rd brake light. There is a rear Bulb Failure Unit which may be giving problems but if the 3rd brake light isn't working intermittently, chances are the connections need cleaning/tightening.

Your car is on the changeover between Bosch ABS and ABS-2E, either way, the ABS warning light is meant to come on during self-check, either it goes out when started (ABS) or after 6-8 seconds (ABS-2E) but either way should be out with the engine running and alternator charging. As such, it sounds like it's behaving itself as it should be.

Does your replacement speedo even look the same? The difference is in the tripmeters and odometers. Yours being a 1992 has a unique speedo/instrument cluster so needs the correct year and just for fun, they had a high failure rate that year!

Those bulbs are an absolute nightmare to get to! I'll give it a go later as it's already ruined my day getting worked up over it. The centre light brake bulb is very intermittent, it's definitely the bulb failure unit. The circular one located in the dash behind the gearstick. Cost a fortune to replace, I've had this car five years so I know it well.

The car starts, no ABS light, drives up to about 15mph and then the ABS light comes on. Classic "no sensor reading" symptom, but could be anything else. Again, no space, time, skill, tools or patience to investigate. Garage admitted they'd struggle as well.

Replacement speedo looks identical apart from the back of it. The car is a 1992 and has an electronic clock adjustment on the dash, near the light switch. The replacement cluster has the manual clock adjustment and is from 1996. The speedo components are both made by Yakazi and look identical on the facia but have dramatically different circuit boards and screw locations. Not compatible in the slightest (despite research suggesting they were the same speedo unit)

This is a new garage to me, I took it to them after not trusting the garage I took it to in March (plus it's closer) - I'm pretty sure as I've been a new customer that they've suspected I'm a DVSA inspector making sure that they are failing cars as necessary. I've certainly had that before where i lived previously.

[loki_the_glt]

An early 945, with orange-coloured indicator lenses, will have a rear fog lamp in each cluster. The usual fail point is a poor connection between the lamp-holder and the power or earth track on the lamp cluster; this can often be rectified by removing the entire cluster, cleaning the track, lightly bending the connectors on the holder and refitting the cluster.

Late cars, with the clear indicator lenses, had only the off-side rear fog lamp; the nearside holder was moulded as a solid part of the cluster and, IIRC, lacked the earth track. Not very economical as they had to produce two distinct clusters for LHD and RHD models; Vauxhall fitted the Zafira B with two lamps but omitted the short power feed with its proprietary electrical connectors on the passenger side

[GingerMagic]

Originally Posted by taiwan740

The car starts, no ABS light, drives up to about 15mph and then the ABS light comes on. Classic "no sensor reading" symptom, but could be anything else. Again, no space, time, skill, tools or patience to investigate. Garage admitted they'd struggle as well

This is a common issue on the 406, where the front reluctor ring develops a hairline crack, not really noticeable but once the car is moving then the centrifugal force will make the crack wider - just enough to trigger the abs sensor....

I'm assuming the Volvo has a similar set up, I've not needed to look as yet....

[Laird Scooby]

Originally Posted by taiwan740

The car starts, no ABS light, drives up to about 15mph and then the ABS light comes on. Classic "no sensor reading" symptom, but could be anything else. Again, no space, time, skill, tools or patience to investigate. Garage admitted they'd struggle as well.

Replacement speedo looks identical apart from the back of it.

Renew your rear ABS sensor - it's in the diff and feeds the speedo as well - this is a hunch so might be wrong, you really need to find someone with an oscilloscope or a multimeter that will read a pulsed output from the diff sensor.

[Forrest]

Originally Posted by 940volvoman

So Dave(Laird Scooby) says that the wire is in place for the nearside fog?

Am I understanding him right,especially as mine is one of the last Celebrations to roll off the production line?

If so I've wasted a good number of years waiting for the "right time" to run a cable from offside to nearside to feed an additional bulb.

In reality it make sense as these cars were also made for left handed drivers(Europe and beyond)

You should find a violet/white wire taped-up behind the nearside rear lamp unit. This already has a spade connector ready to push on to the corresponding terminal on the cluster. An original nearside cluster might be lacking this terminal but a replacement Volvo unit will have it there.

There are two violet/white wires in this spade connector. It is where the wire that goes across to the offside unit connects.

I have found that a UK supplied replacement nearside lamp unit had the bulb holder slightly nobbled to disable this bulb. All you have to do is check carefully if one of the contacts in the bulb holder has been pushed down so as not to make contact with the bulb and restore to its correct position. This has, of course, never been an issue with units supplied mail-order from the continent.

[GingerMagic]

Following on....

I've just been tinkering on the car and I thought I would check my OSR fog light.
Turns out my NS is working but the OS has no bulb in the cluster...!!

As far as I can see I have a wire with a spade connector somewhere floating above the hole, and there are the metal spring tabs fitted on the cluster.

Mine is 1998 so I'm lead to believe that only the OS should be working, but the car did pass an MOT like this.

I guess I should swap the bulbs over to meet with the law

[taiwan740]

Originally Posted by Laird Scooby

Renew your rear ABS sensor - it's in the diff and feeds the speedo as well - this is a hunch so might be wrong, you really need to find someone with an oscilloscope or a multimeter that will read a pulsed output from the diff sensor.

Sounds sensible, the odometer has always worked though. I feel like that would rule out anything non-local to the speedometer/dash cluster, unless the signal is split and there just isn't enough voltage split three ways to operate the speedo, ABS and odometer?

I did get the rear fog light and centre brake light working, but not touched it for a bit. I'm convinced the MOT tester did something to break the ABS, and I don't like mysteries.

[Laird Scooby]

Originally Posted by taiwan740

Sounds sensible, the odometer has always worked though. I feel like that would rule out anything non-local to the speedometer/dash cluster, unless the signal is split and there just isn't enough voltage split three ways to operate the speedo, ABS and odometer?

I did get the rear fog light and centre brake light working, but not touched it for a bit. I'm convinced the MOT tester did something to break the ABS, and I don't like mysteries.

If the odometer is working then so is the rear ABS sensor - the fault obviously lies in the instrument itself and one of your front ABS sensors is faulty.

Did you say they replaced something on the front end or am i mixing this up with a thread on another forum?

[J liddy]

ABS Sensor has been covered before.my light came on I was advised to get a Sensor of ebay About £22 both front plug inn's are easy accessible under bonnet on each wing so unplug each one inturn with the new Sensor as they are both the same each side .this will show if any of these are faulty .Next job replace that Sensor we can guide you through that job too !