The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: mrclubike on December 10, 2016, 05:16:11 PM

Title: Circuits In the US Spec R65
Post by: mrclubike on December 10, 2016, 05:16:11 PM
It is too cold to do anything outside
So i highlighted on the Wiring drawing what each fuse does
As you can see
The left on just carries the brakes horn and turn signal flashers and power for the High beam Pass  Flash 

The right one just basically does the parking light Gauge clusters and tail light

As George has pointed out they did not fuse the critical components for fear of fuse failure
I agree with him because I think the reliability of the fusses at that time was horrible. 

FYI  My 1996 Land-rover Discovery does have fuses for the headlights  and everything else for that matter  but it also uses  ATC blade fuses
Title: Re: What the fuses do In the US Spec R65
Post by: mrclubike on December 10, 2016, 05:18:17 PM
And the Right side Fuse
Title: Re: What the fuses do In the US Spec R65
Post by: mrclubike on December 11, 2016, 12:25:10 AM
Here is the low Beam headlight circuit
 
The reason the headlight goes out during cranking is because the headlight relay gets its ground thru the starter solenoid and when battery positive is applied to the solenoid during cranking
That causes  battery  pos  to be applied to both sides of the headlight relay coil and that  causes the relay to open shutting off the head light
Title: Re: Circuits In the US Spec R65
Post by: mrclubike on December 11, 2016, 09:22:39 AM
Here is the High beam circuit
It operates the same as low beam during cranking
Title: Re: Circuits In the US Spec R65
Post by: mrclubike on December 11, 2016, 09:24:57 AM
Here is the Key to the wiring Diagram
Title: Re: Circuits In the US Spec R65
Post by: mrclubike on December 11, 2016, 09:52:17 AM
This is the Passing flash circuit
it gets its power from the left fuse
This is because in the EURO spec bikes you can turn the head lights off and you need another source for battery positive to flash the head lights

You may be wondering why does the power go all over the bike just to get back to the headlight dip switch
It is wired in a big chain a lot like a Christmas tree light string that  is wired in parallel
Title: Re: Circuits In the US Spec R65
Post by: mrclubike on December 11, 2016, 10:35:50 AM
Left Turn signal circuit

Notice the power goes to the kill switch but does not go thru the kill switch to power  the turn signal flasher

Title: Re: Circuits In the US Spec R65
Post by: mrclubike on December 11, 2016, 11:01:04 AM
Why is it better to use a relay on the Horn?

Look at what it takes to get the power to the horn  :o
It is the last thing on the power chain
Title: Re: Circuits In the US Spec R65
Post by: mrclubike on December 11, 2016, 12:05:17 PM
Here is what the Battery positive to the horn looks like on the Bike
Title: Re: Circuits In the US Spec R65
Post by: Tony Smith on December 13, 2016, 12:30:13 PM
Thank you for your time to highlight the various circuits - most interesting.

What it does do however it throw firmly on its ear my theory of what cured my starting problems. Obviously I have disturbed something for the better in my ferreting around the harness - but the fuses were not "it".


Think I might have another look this weekend.
Title: Re: Circuits In the US Spec R65
Post by: JJH on December 13, 2016, 03:04:39 PM
Thanks!  This is a great resource.
Title: Re: Circuits In the US Spec R65
Post by: skippyc on December 13, 2016, 03:31:38 PM
Does anyone have a circuit for an 1986 model.
Title: Re: Circuits In the US Spec R65
Post by: mrclubike on December 13, 2016, 08:19:02 PM
Quote
Does anyone have a circuit for an 1986 model.

See if this works
Unfortunately it does not show the insides if the relays

http://www.powerboxer.de/images/stories/schalt_wart/schaltplaene/im_12_r65-80-100rs-rt_85-87_schaltplan_e.gif
Title: Re: Circuits In the US Spec R65
Post by: skippyc on December 14, 2016, 05:18:09 AM
Quote
See if this works
Unfortunately it does not show the insides if the relays
Thanks it is a good start to work from.