Author Topic: Starter relay (Read 53868 times)

A · « **on:** May 18, 2011, 08:44:36 AM »

1985 BMW K100 naked.

Starter seems to crank whenever the battery is connected to the wires.

What to do to get to the starter relay?

Can the relay be repaired or only replaced?

Where is a good source to find replacement starter relay?

Any less expensive replacements than BMW OEM Bosch units?

Please provide links if you know of any.

Thank you

A

frankenduck · « **Reply #1 on:** May 18, 2011, 10:54:08 AM »

Usually this is caused by trying to start the bike with a low battery. The relay contacts don't fully engage so a spark develops between them which welds the contacts shut so that the relay does not disengage.

The starter relay is located in the right rear corner of the relay box under the rear of the fuel tank:

Sometimes this can be cured by taking a crescent wrench or whatever and giving the right rear corner of the relay box a sharp rap.

There really isn't a direct replacement other than the K bike starter relay.

Good used parts can be found here: www.kbikeparts.com That's me. The page is a bit out of date though so if there's something you need but don't see then drop me an email. I do have good used starter relays.

A · « **Reply #2 on:** May 18, 2011, 02:52:07 PM »

Thanks, I just replaced the old battery to a new one that passes voltage test and load test with flying colors..
Whenever the battery cables are connected tot eh battery, the starter would start cranking without me hitting the starter button on the handlebar.

Seems to be a common occurrence of starter relay going faulty due to low voltage battery, but I'm surprised that among BMW owners no one has come up with or found an alternative to the flimsy Bosch relay.. ? ???

johnny · « **Reply #3 on:** May 18, 2011, 03:04:39 PM »

greetings a...

yawl bro... i dont recall those starter relay contacts fusing together very often... and when they do i recall it always being due to a low battery... and when you consider busting the contacts open is pretty easy... the need to find an alternative has not been a priority... if you find a suitable replacement let us know...

so whats the deal... your battery is good... did you free the contacts...

j o

frankenduck · « **Reply #4 on:** May 18, 2011, 05:53:33 PM »

A flimsy battery is the issue, not a flimsy relay.

It's just a relay. If you wanted to you could swap in any "normal" relay as long as it's rated for the amps that the starter pulls. Not sure what that number is though. You'd probably have to redo the terminals on the wiring though.

Belplasca · « **Reply #5 on:** June 01, 2011, 10:39:42 AM »

Quote from: frankenduck on May 18, 2011, 05:53:33 PM

A flimsy battery is the issue, not a flimsy relay.

It's just a relay. If you wanted to you could swap in any "normal" relay as long as it's rated for the amps that the starter pulls. Not sure what that number is though. You'd probably have to redo the terminals on the wiring though.

It's actually a Bosch "0 332 002 161" which may be available from Bosch dealers...

Bob

frankenduck · « **Reply #6 on:** June 01, 2011, 10:49:53 AM »

Just because it says Bosch and has a number on it doesn't mean it's not specific to K bikes. For example, the L-Jetronics of K75s and K100 say Bosch and have numbers on them and those are most definitely specific to K bikes.

Belplasca · « **Reply #7 on:** June 01, 2011, 12:32:12 PM »

Quote from: frankenduck on June 01, 2011, 10:49:53 AM

Just because it says Bosch and has a number on it doesn't mean it's not specific to K bikes. For example, the L-Jetronics of K75s and K100 say Bosch and have numbers on them and those are most definitely specific to K bikes.

But, in this case, it's a standard Bosch relay...

Bob

frankenduck · « **Reply #8 on:** June 01, 2011, 12:53:47 PM »

Quote from: Belplasca on June 01, 2011, 12:32:12 PM

Quote from: frankenduck on June 01, 2011, 10:49:53 AM
Just because it says Bosch and has a number on it doesn't mean it's not specific to K bikes. For example, the L-Jetronics of K75s and K100 say Bosch and have numbers on them and those are most definitely specific to K bikes.
But, in this case, it's a standard Bosch relay...

Bob

What makes you so sure? I tried Googling that part number and nothing came up. If you have a source for it other than BMW I'd be interested in knowing about it.

Also, be careful using the term "standard Bosch relay" because that generally refers to one of these in the four or five pin configuration:

The K bike starter relay looks nothing like that.

Inge K. · « **Reply #9 on:** June 01, 2011, 08:13:17 PM »

FYI: Some Bosch standard relays...page 14:

http://www.boschmotorsandcontrols.co.uk/relais/relais.pdf

Inge K.

hbanbury · « **Reply #10 on:** July 22, 2014, 10:29:09 AM »

Update on this topic FYI...

This replacement Relay is currently manufactured by Tyco in Portugal in the same Factory Building that Bosch owned.

TYCO / Siemens Electronics equivalent TYCO purchased the Bosch Relay Division .

Bosch no longer manufactures relays; they are all made by Tyco and private labeled for Bosch by Tyco.

PLEASE MAKE SURE YOUR BATTERY VOLTAGE IS 12.6+VOLTS. NO WARRANTIES FOR STUCK RELAYS

NOTE:
Check battery health and voltage.
Low battery voltage will cause any electromechanical relay to stick and malfunction, causing eventual failure.

NO WARRANTY WILL BE HONORED FOR RELAY POINTS WELDING TOGETHER DUE TO LOW VOLTAGE BATTERIES.

Available here...
http://www.euromotoelectrics.com/BOSCH-Starter-Relay-BMW-K-61-31-1-459-008-p/rel-k008.htm

cmattina · « **Reply #11 on:** July 22, 2014, 10:41:55 AM »

Although I am relatively new k-bike owner I can say for certainty, that the problem you are having may not be caused my the relay or the battery.

It has happened twice to me, each time my clutch had something to do with it! The first time it happened after adjusting the kickstand return mechanism (i must have did it wrong). The second time I got home from doing errands, turned the bike off and the starter continued to run. I figure it's the relay, so i go buy a 70 dollar non-returnable relay from Napa, they have the alternative as laid out in the Liebrary. Put in the new relay, and the starter continued to run... Now I have a "spare". Since the new relay did nothing, i look at the clutch - my locknut had backed all the way out (I remember when i snugged it up i didn't give it as much as I normally do).

However, re adjusting the clutch did not fix my problem, neither did changing the relay. My battery showed "low" on my auto charger (but, of course it did it was running my starter for a combined minute and half as I was trying to get test it and shut it off).

So, i charged the battery, removed and inspected the starter, cleaned the ground contacts connected to the starter, and the problem was fixed. Don't know what or why. However, i still believe the clutch had something to do with it. My battery tests good and my bike starts good every time, i think it was low AFTER the starter got stuck. My k bike is very clean and all my contacts were clean to begin with and I also do not believe my battery had anything to do with it.

don't go replace the starter relay before inspecting the clutch, and cleaning the ground points around the starter (and removing the starter if you have the time). Perhaps a low battery had something do with it AFTER i adjust the clutch, because by the time the battery had BECOME low.

gladstone · « **Reply #12 on:** July 22, 2014, 05:39:20 PM »

I had the same issue as the original post in that cranking on a low battery fused the relay. I was so convinced it was going to catch fire (things got very hot) I quickly wheeled the bike out of the garage and it dropped down a small kerb and jarred the relay free.

A new battery solved the issue. NEVER crank a K on a low battery.

Cheers

gpcrane · « **Reply #13 on:** July 29, 2014, 01:27:11 AM »

Same problem here. When I disconnected my batt. (to stop the starter) I noticed the pos. leed was not tight (no lock washer). My fault on that since I changed the batt. over the winter. Followed the advice from a earlier post and hit the elec. box in the right rear side with a wrench (my favorite way to fix things (see avatar)). It worked :clap: Thanks for saving me the bother of buying a new relay, pulling the tank and missing great weather.

Cheers

Greg

umichchris · « **Reply #14 on:** October 30, 2016, 08:22:23 PM »

Hey everyone, i'm also experiencing this problem. given that ive only owned the bike a week, im not very familiar with the bike/platform but im pretty handy in the garage.

Here's what's happening...twice in the past week the starter will not shut off. the killswitch would not make it stop the first time it happened nor would removing the key. in order to get the system to shut down i popped it into gear and released the clutch and the bike stalled and the starter finally stopped.

this happened a second time in one week so now i dont want to ride the bike until i get to the bottom of the issue. the issue has only happened twice and ive been riding the bike nearly daily in the past week.

the previous owner told me he recently replaced the battery (it looks brand new). he also provided a batter tender as well. right now i have the system charging (in hopes that its just low voltage).

in order to check/test the starter relay, i need to remove the gas tank? im guessing ill need to drain all the fuel from the tank first before removing (that sounds like a very long process). correct?

thanks for your help!

mystic red · « **Reply #15 on:** October 30, 2016, 08:58:53 PM »

No need to drain the tank. Just plug the lines when you disconnect them. I use golf tees.

Filmcamera · « **Reply #16 on:** October 30, 2016, 09:01:56 PM »

You don't have to drain the fuel to remove the tank, do you have a workshop, Clymer or Haynes manual? If not a download is available on this site...

umichchris · « **Reply #17 on:** October 30, 2016, 09:07:51 PM »

Quote from: Filmcamera on October 30, 2016, 09:01:56 PM

You don't have to drain the fuel to remove the tank, do you have a workshop, Clymer or Haynes manual? If not a download is available on this site...

yup, the previous owner gave me a new Clymer book when i bought the bike, taking a deep dive into it now...

sounds like i need to check the starter relay (maybe replace it), check the connections on the stater itself and ensure they are not loose...thats my first line of attack for now

mystic red · « **Reply #18 on:** October 30, 2016, 09:20:51 PM »

There ya go! If battery is good, check the connections.😆

Martin · « **Reply #19 on:** October 30, 2016, 09:22:53 PM »

I've had my k75 for approx 16 years .Just after I got it the relay stuck and the starter just kept cranking until the battery overheated & the side of the battery blew out.Battery acid everywhere lucky I had access to plenty of water.After it happened for the second time & I knew to disconnect the earth lead( resulting in one burnt finger.I have now fitted an in line battery isolator switch ( the smallest I could find).This has been fitted behind the side cover it required the cutting of the earth lead & removing a short length of cable to accommodate the switch and soldering in two lug connectors.I can now isolate the battery and it can be used as a security device by removing the key.You can access the switch without having to remove the side cover.Somebody else pointed out that he had a Ural which was fitted with one as standard. It was handy when you wanted to work on the bike & needed to isolate the electrics. You can pull apart the relay and clean up the points. http://www.motobrick.com/index.php/topic,8995.msg70926.html#msg70926

Regards Martin

umichchris · « **Reply #20 on:** November 03, 2016, 03:13:02 PM »

Hey everyone, i thought that since i just bought the bike, perhaps the battery was low and needed a solid charge...that was one of the top suggestions for a fix. So.....i connected the bike to the battery tender each night after riding throughout the day for the past week. No issues.

BUT THEN...today while on my way into the office i could hear the starter continually running. In addition to that, the electronics on the bike were malfunctioning. The headlight would not turn on and my turn signals intermittently would not work either. Right now, im just planning to ride home midday and park the bike before it gets dark out.

The start would not shut off until i un-bolted the negative cable on the transmission (luckily i was prepared for that thanks to your suggestions - thanks again all).

So, now...im not sure where to start. Its definitely not a low battery issue. I can see in all of the paperwork and maintenance records from the previous owner that the starter relay was replaced back in 2014...so this may be a recurring problem...wish me luck!

umichchris · « **Reply #21 on:** November 21, 2016, 04:03:03 PM »

took everything apart....gave the relay a sharp tap like suggest within this thread and others...put the bike back together and the issue came right back after a couple of starts.

i just ordered a new relay today. hopefully it arrives this week so i can install this coming weekend.

all connections are nice and tight. my battery is pretty new (replaced in February of this year). the voltage output reads roughly 12.89v when i put it on a tester so i dont think thats the issue.

hopefully a brand new relay will fix the problem. ill be sure to report back...

Martin · « **Reply #22 on:** November 21, 2016, 04:06:02 PM »

Did you clean up the point surfaces with a points file or fine emery paper.
Regards Martin.

umichchris · « **Reply #23 on:** November 21, 2016, 06:22:58 PM »

Quote from: Martin on November 21, 2016, 04:06:02 PM

Did you clean up the point surfaces with a points file or fine emery paper.
Regards Martin.

hmmm, i checked all the external connections and made sure they were clean and secure, but i did not open up the relay housing itself. with a new one on its way now, i suppose it wont hurt to (gently) crack it open now anyway...

Martin · « **Reply #24 on:** November 21, 2016, 06:35:54 PM »

Some can be cleaned up, some can't but you have nothing to loose.
Regards Martin. :2thumbup:

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Author Topic: Starter relay (Read 53868 times)