Volvo 480 Club Europe

Well well, I have finally done it, I have on my drive a lovely 1992 volvo 480 ES.

Stuff that doesn't work:
Indicators (hazards are fine)
Radio
Interior light
electric windows (get stuck)
Boot leaks
Seat runners are stuck
Information display, seems to work but no back light
heated seats don't work, think switches are knackered.
drivers mirror moves vertically but not horizontally

I am sure there are a few other things to, but the car runs and rives ok so I guess its a case of working through the above list.

I have started with the indicators as this is the most important thing in terms of safety and getting it through an mot.

I started looking at how the indicator circuit works, it seems that the hazard lights and the direction indicators use the same relay, the hazards pull an enable line to ground which turns on a low frequency square wave generator which determines how quickly the relay is energized / de-energized. The hazard switch seems to have two switches built into it, one which pulls the enable line to ground, and the other allows current to flow through the relay contacts to the indicator lamps.

Firstly I wanted to see if the actual indicator stick switch works, to do this I bridged pins 3&4 of the hazard warning switch, this has the effect of enabling the relay, but with the hazard switch in the off position will not allow the indicator lamps to illuminate. This had the effect of turning the relay toggling circuit on and I could hear that the relay was switching on and off but twice as quickly as usual. When I engaged the indicator stalk the indicators worked both left and right, when I put current through the relay contacts the relay slowed to a more normal flash rate. This means that the switch and associated wiring is good.

So where to now? On the wiring diagram there is another line going into the relay circuit pin A32 on the CEM, is this line supposed to be pulled high or low whilst in normal operation? I will experiment more tomorrow as I have run out of light today.

If anyone has any ideas as to why my indicators will not work I would be glad for any clues.

Does this help?

Hi,

I had the same problem - hazards working and indicators not working. I found myself here looking for answers so thought I'd post what I found.

I did a similar fault finding, check continuity of indicator switch, check all pins from hazard switch are making and breaking correctly, finally I looked at the CEM 3. I looked for dry joints and couldn't find any, then found corrosion joining two pins and then on closer inspection corrosion coming out of the bottom of an IC.

Anyway CEM 3 replaced with a spare and all is well. Indicators working correctly. One step closer to a MOT.

Congratulations on your purchase, and welcome to the club. You are in the right place for lots of help.
I can help with the boot leaking - it's probably the rear light seals in combination with the hatch seal and electrical connection.
Rear lights are gold dust so be very careful removing them and make sure you find the hidden screw near the top of the upsweep.
New seals can be cut from suitable closed cell material, or I think someone on here sells repros. Don't be tempted to just silicone the lights, you'll never get them back out intact and they do need polishing from time to time.
The rear hatch seal can be replaced with one from a 440/460 which has an extra lip, should be reasonably easy to source from a scrappie.
Also check where the wires run through to the hatch, if it's still there the rubber seal around them may be letting water in to run down the wires.
Good luck !

If the hazards are working and the indicators are not, the problem is either in the column stalk, the hazard switch or the wiring between them, not in the CEM! The CEM has a completely separate circuit for the flashers, what usually fails is the flasher click throught the built-in speaker.