replacing or repairing light switch '83 R65

[curtb]

Hi all,

I've owned this for 4 days now so please excuse any newbie actions on my part.

Low beam and front parking light don't come on at all, high beam only with the "dip" on the switch. I've doused the inside of the switch with electronic cleaner to no avail. When I jump the switch with my little screwdriver across the terminals on the back of the switch, I can get all three lights to come on.

Seems like the switch is the culprit but it looks like a pain to replace. I haven't torn in to it deeply because I suspect there are tiny springs and such inside.

Anyone offer sage advice and guidance?

Thanks

 

[20774]

Welcome to the forum! Glad you're getting to know her!! I'm thinking maybe not the switch. My SWAG is the headlight relay is bad. Would be interested to hear other ideas.

 

[stevenrankin]

Test

Test each of the wires for current at the switch. You will need a wiring schematic. It does sound as it is possible the switch is bad as you can get things to work by jumping connections. Test your jumping with the schematic to make sure you are creating the proper circuit you intend to engage. If you complete the circuits according to the diagram by jumping, you could have a bad switch.

At the same time, you can check to see if you are getting current in the right wires to the relay. If not, it could be the switch. LOL, the relay is easier to change than the switch and most likely cheaper, so it is a toss up if you just want to plug in a new one, if it works, fine if not, then you will have a new relay and switch.

I hope this advice makes sense? It is easier to do than to describe. Good luck. St.

 

[curtb]

Test each of the wires for current at the switch. You will need a wiring schematic. It does sound as it is possible the switch is bad as you can get things to work by jumping connections. Test your jumping with the schematic to make sure you are creating the proper circuit you intend to engage. If you complete the circuits according to the diagram by jumping, you could have a bad switch.

At the same time, you can check to see if you are getting current in the right wires to the relay. If not, it could be the switch. LOL, the relay is easier to change than the switch and most likely cheaper, so it is a toss up if you just want to plug in a new one, if it works, fine if not, then you will have a new relay and switch.

I hope this advice makes sense? It is easier to do than to describe. Good luck. St.

Done. I'm 95% certain it is the switch at this point. I ordered a replacement. Thanks

 

[curtb]

Welcome to the forum! Glad you're getting to know her!! I'm thinking maybe not the switch. My SWAG is the headlight relay is bad. Would be interested to hear other ideas.

Thanks...this model has no headlight relay.

 

[stevenrankin]

Headlight relay

Well, I be darned, you say no headlight relay, I guess I will have to look it up in my Haynes manual this morning.

I kind of find that hard to believe. The reason I say this is because the current flowing through the switch in most BMW airheads in 83 was lower amperage than what would be needed to control or supply the headlight high and low beam. Hence, a relay is installed into the wiring. This was done to "save" the switch from higher amperage current needed to light the headlight.

At least the switch you need is still available, some are not. Good luck, St.

 

[curtb]

Well, I be darned, you say no headlight relay, I guess I will have to look it up in my Haynes manual this morning.

I kind of find that hard to believe. The reason I say this is because the current flowing through the switch in most BMW airheads in 83 was lower amperage than what would be needed to control or supply the headlight high and low beam. Hence, a relay is installed into the wiring. This was done to "save" the switch from higher amperage current needed to light the headlight.

At least the switch you need is still available, some are not. Good luck, St.

Me, too. But the wiring diagrams in both the shop manual and the rider's manual agree. All the juice runs through the switch. Maybe that is why the switch fails?

 

[20774]

Is your bike a European model? My Haynes shows "US Only" on the light relay in the diagram.

 

[curtb]

Is your bike a European model? My Haynes shows "US Only" on the light relay in the diagram.

I think the VIN decodes as a US model. I don't have a haynes...been using the BMW shop manual and the wiring diagram from the rider's manual.

 

[20774]

So, I take it that your manuals and diagrams matches what you see on the bike?

 

[curtb]

So, I take it that your manuals and diagrams matches what you see on the bike?

yep

 

[stevenrankin]

Lol,

This is one reason why sometimes multiple wiring schematics are needed. BMW does something and doesn't update the manuals or you got a manual before an update, who knows?

I looked in my new version of the Haynes manual and sure enough it lists a headlight relay for the US model but not the UK.

The UK only apparently is a yellow/white wire from the left handlebar control set direct to the ignition switch. A white wire from the handlebar control set to the headlight.
In the US, the yellow/white goes to the relay and a green/violet wire comes from the ignition switch to the relay instead of the yellow/white wire from the switch.

Regardless, as I am not an engineer and only have a bit of electrical knowledge, I would put the premature demise of the switch down to higher amperage load passing through it rather than it controlling a high amperage load via a relay.

But then what do I know, I don't make the big engineer bucks. St.