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90 k75rt lights stay on with or without key

kkeller149854

K75RT Keith
Started the K75RT (48k) today and when I shut it off and turned the key switch to the OFF position, all the lamps remained lit. Headlight, gauges, taillight, markers all stay on no matter the position of the ignition switch. Key in or out it stays all lit up. Disconnected the battery lead so as not to kill the battery. Any suggestions where to start looking?
 
I'd suspect the load-shed relay first. If you reconnect the battery lead and the lights come back on, see if they go off when you crank the engine over (while the starter is running.) The load-shed relay should drop out when the starter is running and shut them off. I believe it also drops out when the ignition is turned off.. and it sounds as if yours isn't.
 
Yep.

Had a very similar problem with my 85K100. A new relay is in order - a few bucks at NAPA will fix your problem if I remember correctly.
 
Does yours indeed not drop out when cranking, like Don suggested?

I'll check the number and see if I have a couple spares AFTER the Daytona 500 is over.



:dance:dance:dance
 
Thanks , I would really appreciate that number.

I hit the starter and all the lights stay lit. If you do have a spare, let me know the part number. Or, if it is for sale

Got that sinking feeling in my wallet that i'm going to have to do the relay and a switch.
 
The Bosch # is 0 332 014 454. It is a 30amp 4 pin relay.

You will find a lot of mistaken and contradictory information in the Clymers manual, BMW manual, and the BMW parts fiche. The relays and their layout changed a few times over the years. Even the parts fiche seems to have it wrong.:dunno

The best way to confirm your problem and which relay is bad, is to lift the tank and the relay box cover. Then turn on the key and make sure that your horn honks. Then try pulling the right front small square relay and retry the horn. If indeed that is your horn relay, the horn should not honk, if it is not, try other small square relays one at a time until you locate it (pre '90 bikes it should be the right front).

After you locate the horn relay, leave it out. Now pull similar relays until you find the one that makes your headlight go out. Make SURE it is a 4pin relay with the same diagrame on the side as the horn relay. Now replace it with the good horn relay (they are the same part #). Hopefully, the headlight will now work correctly. If so, you could take the bad relay to any car parts house and get a replacement and put it in the horn spot. If you can't get one immediately, you can still ride with out the horn relay until you get one. PM me if you can't locate one.



:dance:dance:dance
 
Thanks Lee, If I am not mistaken, the relay is blue in color. and if that is the case, I have a spare that came with another purchase. I'll dig into it if we have a warmish day this week.
 
Yes, it's light blue. On my bikes, the horn relay is the right front one and the load shed is right next to it.

:dance:dance:dance
 
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