Strange Light-switch problem

[Hendrik]

In my (Japan made )wagon 1986 , 4wd , turbo , the light switch is combined with the parking light switch , and the inner axe has the dimmer function for the (digital) dashboard. See picture.....

 

The high/low beam selection is with a separate up/down switch under the steer.

 

Inside the housing of the switch are a lot of electronic components.

 

The dimmer function no longer works , always on maximum , turning

the inner knob does nothing anymore.

And the "Illumination "fuse always burns out...

 

All the lights work fine........

 

I did not find documentation for this switch , anyboy can help me ?

[Cougar]

It sounds like you may need to replace the switch. The shorting problem may be due to a problem with the switch itself or in the lighting system.

[Hendrik]

It sounds like you may need to replace the switch. The shorting problem may be due to a problem with the switch itself or in the lighting system.

 

I am an elctronic engineer , but even so you need to know the ins and outs

of the circuits. I have a FSM for an 88 model and also earlier ones : not for 86.....

 

It is a bit complicated as some of the switching is done at ground level and some at +12 volt. I still doubt if it is the switch.

Any way , in this country a Subaru is like an elephant in Alaska.....

Parts : a dificult story , junk yards do not have them.

 

I believe to be able to fix it , if I have the right docs.....

[Cougar]

I'm an electronics tech. Using your DVM will tell you what wires are hot or tied to power and which ones go to ground or have a load on them.

 

I would think the electronic components you saw in the switch are used as a regulator circuit for the dimmer. Other lighting controls are usually just make or break switch contacts. Since the dimmer isn't working I would suspect the regulator is shorted. If you can work on the components you may be able to replace the bad ones and fix the dimmer.

 

To find the short I would remove leads that go to ground and reconnect them one at a time to see which one is causing the trouble. If there is more than one lead going to ground.