In the dark - light relay ?

[fritz]

Help ! Has anyone experience of testing these ? The Haynes Manual carries nought, haven’t checked Clymer.
What happens when one fails ?
I’ve lost my low and high beam except on ‘flash’.
I have parking lights, and I can ‘flash’ main-beam. No dip at all. Obviously bulb works and fuse OK. Could be switch, relay or wiring. Didn’t find anything obvious before frostbite started to set in on Saturday.
If relay fails would main beam work on ‘flash’ ? and of course parking lights – would they work with a failed relay ? I assume it’s got to be either switch or wiring at fault.
I have Wednesday off to suss it; any advice in advance would be helpful ! Its the '89 R100GS Custom (ie it's customary it fails to work !)
It's the same post under Airheads !

 

[ferguscawley]

Corroded switches !!

Fritz

A friend of mine with a 1994 1100GS had exactly the same problem last week. We had a look at all the wiring diags etc and then tried to find the relay (there is none !!). The lights are switched at the lefthand handlebar switch. The right hand light switch just provides a feed across to the LH switch cluster, which then selects low or high beam.
We disassembled his LH switch and found that the contacts inside had corroded and come off. There was no way to fix this. Only solution is to ring Motorworks and order a new switch assembly. It is simple to replace as it comes with the wiring loom attached. Just lift the tank and slide it back about 8 inches, unplug the connector (top left as far as I recall) and install the new one. Easy to find anyway - just follow the old cable from the switch assembly back down under the tank.
I think the switch assembly cost him about STG40.00.

I reckon that the reason the contact burned out was due to several reasons :
1 age
2 moisture entering
3 He was using a 80/100 watt bulb which resulted in increased current running through the already weak switch contact, burning it out prematurely.

Any questions, don't hesitate to ask.

Ferg

Shit - just realised that you have an airhead. Anyway, I'm sure the wiring is very similar. Doh !!

 

[Rob Farmer]

Fritz,

The flash has a seperate feed (green wire in switchgear), this feed is common with your brake light switch, horn and ignition. This leaves two choices 1/ light relay 2/ ignition/lighting switch.

Hopefully you have either a meter or a test bulb.

First thing to try is:

A/ terminal 56 on the ignition switch (white with yellow tracer) should have 12V on it when the switch is moved to the light position if it has then -

B/ Terminal 86 on your light relay (the other end of the white/yellow wire) should have 12V dc on it with the ignition in 'lights on'. if it has the relay should operate when you turn the lights on or off.

c/ Terminal 30 (Red wire) on the lighting relay should have 12V on it straight from the battery.

d/ if the relay has drawn in then you should have power going to the high/low switch from terminal 87 (yellow wire) of the relay, if you have and then the chances are the high/low is fried.

I hope this helps

 

[fritz]

Cheers folks. Have just discovered on the handbook that it appears a previous owner has indicated a 4amp fuse twixt battery and relay. If it exists, I guess it coukld be this. Anyway, I will done every item of warm clothing tommorrow a chase round the wiring 'til it's found or I retreat to drink ! Thanks for info's will be checking them out.