Several electrical problems

[4486]

Since the last 3 months my 1986 volvo 480 is getting me crazy with almost every electrical part. The headlights don't go up, the back lights neither. The heating system don't work, the info center and the backlight of the speedometer don't shine as needed... Every problem arrived at the same time so I suppose it must be a cem problem. I tried to remove it to see if every connector is connected properly but I cannot get it. I don t know how to do it. Thank you very much.

[glasgowjim]

While I can sympathise with your angst , calm down and list the problems in order of importance and we can solve them.
Some of your descriptions dont make sense. Help us help you by being as detailed a\and specific as you can.

instrument lights out are nothing to do with the cem. the bulbs are blown each lighted logo has its own bulb , the speedo also and the info centre has its own high wattage bulb. simply remove and replace.

The heater is simple to check start with the fusebox and check all fuses just to eliminate all possible problems.

It is likely that the heater motor is dead but you can check it out easily. So not a major problem.

But then you didnt say whether it was the heater fan/motor or just there was no heat coming from the heater as that is a different problem with a different solution.

the popups are again just a matter of elimination we can take you through that step by step - have never been beaten yet by a popup

Still I have said enough when you post up a coherent and detailed description of each problem then I or other members can can take you through the solution step by step.

[4486]

I will try to explain the problems and how they occured.

When i bought the car 10 months ago it was apparently in good conditions. Everything worked and i was happy about it. Problems started about 6 months ago when i put the lights and the headlight cases didn t go up. I put the cases up manually and saw the lights were ok. I verified relays and fuses and there were all ok. A week later y put on the heater and it didn t work. Y verified fuses and were ok. Some time later i noticed that people on the road told me to put on lights because backlights didn t work. I verified fuses and were ok. However i saw that the control of lights didn t make good contact and there was a position that makes backlights work, but also make that the right indicator shines everytime.
The problem i told you with speedometer and info centre is the faint retrolight, which don t let me see nothing.

As there are many different problems i thought it was a cem problem, cannot be?

[Captain Slow]

Some time later i noticed that people on the road told me to put on lights because backlights didn t work. I verified fuses and were ok. However i saw that the control of lights didn t make good contact and there was a position that makes backlights work, but also make that the right indicator shines everytime.

A problem with a crossed wire? maybe damaged in the boot? what happens to the brake lights when you brake?

As for the dim instrument cluster, that will likely just be blown bulb(s)-easy enough to replace.

[Captain Slow]

Further, there are many posts on troublesome popups-you can do a search. Are the DRL bulbs the correct matched 21W/4W offest pin types? The popup issuea may be related to the rear light problems.

[glasgowjim]

My daughter's 480 had a major popup episode they would go down but not up so after hours of trying everything I got i them to work

1 removed popup relay and checked the wiring to motors
2 changed the headlamp and popup relays
3 changed cem 3
4 changed rotary switch checked fuses 3 times

stil no joy so as a last resort douyble checked the dlrs . and was the nearside one faulty . What a fault one of the elements was too long and had crossed with the other element in the bulb this caused the malfunction.

At this rate I should be getting a Phd in 480 popupology

[glasgowjim]

did you remove the tall popup motor relay and bridge the connections to make the popups go up and down?

have you checked the earths for the rear lights?

what about the lampcontroller unit?
the red unit in the picture ( click on link below)

http://i223.photobucket.com/albums/dd27 ... ial007.jpg

[4486]

I have already tried 3 tall relay and with a wire on the correct pins I saw the pop up motors go up and down very quickly and without stopping so the motors are ok.
What do I have to do to check the earths because I have seen many wires not connected.

I do not know how to change the cem and where is the cem 3, my car is from 1986.

I have seen the picture you told me and I don t know where is the red thing you told me.

Thank you all for your help

[glasgowjim]

1986 does not have a cem3 unit

the red unit is behind the rear side interior trim next to the aerial. There are 2 types of these red lampcontroller units.

Where are you ?

[glasgowjim]

Look up this thread and you will see how to access the lampcontroller unit.

http://volvo-480-europe.org/forum/viewt ... 24&t=19608

[4486]

I am Spanish but the car is imported from Belgium . I have found the lamp controller but I do not know what do I have to do with it, check the connections replace it with another unit?
Yesterday I went to a scrap yard and bought the connector where the light controller on the dashboard is connected. I would like to replace mine and try with the "new" one. The problem is I don't know how to remove the wires connected to it. Could it be there the problem?
Also I noticed the problem of the heater is not on the heater motor but in the controller of speed because I can hear the motor work but there isn't any difference between speed one and max speed, and also I cannot swith it off, the motor doesn't stop working.
Thank you once more

[glasgowjim]

Does your car have air conditioning ?

The fault with the speed variation is I think due to the resistor unit which may be defective. Will try and post up a picture for you but I am very very busy today.

[4486]

It doesn't have air conditioning.
Do not worry i can wait for your answer.

[glasgowjim]

I have not forgot about you .

Will post soon.

[glasgowjim]

here is the photograph of the heater and the resistor mount in place.



I will post up 2 photographs of the resistors for you.

[glasgowjim]

The resistor unit in fact holds 3 coiled resistance wires . The first thing I would do after checking the switch unit is to remove the resistors and check the 3 coils of thick BARE wire have not bent and come in contact with each other . They may even have only sooted up and need cleaned. If you do need a replacement unit I can supply one





hope this helps mi amigo

[nemielas]

Since the last 3 months my 1986 volvo 480 is getting me crazy with almost every electrical part. The headlights don't go up, the back lights neither. The heating system don't work, the info center and the backlight of the speedometer don't shine as needed... Every problem arrived at the same time so I suppose it must be a cem problem. I tried to remove it to see if every connector is connected properly but I cannot get it. I don t know how to do it. Thank you very much.

I'd put my bet on one of main ground connections somewhere if all of the sudden these problems fell off on your volvo.

[Dan the 480 Man]

I'd have a look at the 80 amp mega-fuse. It's above the radiator near the alternator in a black plastic housing. It's like a giant bladed fuse. If I remember rightly it's not clear though, so you will need a multi-meter to test it. Don't ask me for the correct values because I don't remember them!

Do people unplug the ECU these days too? Just remove the plug from the ECU under the centre console and leave it for about an hour, this sometimes helps to clear up little niggles etc. And, one further thing: do all the 480's have the little black diagnostic box near the suspension mount under the bonnet? If so, you can perform a diagnostic yourself, in which the unit gives a series of 3 flashes. These 3 flashes will then indicate what error there maybe.

:: Edit :: This is the diagnostic box info HERE.

[glasgowjim]

it is a 1986 early model it will have a cem 2 and no megafuse and no diagnosis box.

unless the previous owner has taken it to have one fitted , it was a recall job I believe.

[4486]

Since the last 3 months my 1986 volvo 480 is getting me crazy with almost every electrical part. The headlights don't go up, the back lights neither. The heating system don't work, the info center and the backlight of the speedometer don't shine as needed... Every problem arrived at the same time so I suppose it must be a cem problem. I tried to remove it to see if every connector is connected properly but I cannot get it. I don t know how to do it. Thank you very much.

I'd put my bet on one of main ground connections somewhere if all of the sudden these problems fell off on your volvo.

This could be the problem but i do not know how to check it. Which wires are the main ground connectors?

Another problem that I forget to tell you is the discharge of the battery in a couple of days being the battery about 6 months old.