headlights and cpu lamp issues

[Max]

First issue with the 87' in a few years, guess it was a matter of time. Three symptoms are solid, no high and low beam and dash CPU lamp. All other lights and signals are good. There are no other known issues. CPU cycles it's self check normally turning ignition on and no warning indicator after. All other CPU functions are normal. Bike starts and runs fine. Replaced bulb. Fuse ok with 12v measured on both sides of fuse with ignition on. Flipped high/low beam and On/Off switch a few times and reseated whatever connectors accessible behind the headlamp. Tried flexing exposed wiring and connectors. Can't even get the lights to flicker once.  Couldn't find a common connection on the schematics. I would appreciate any advice. Thanks in advance.

[Marcarl]

My first go to in your case would be to take the high/low beam switch apart and clean it and make sure it is all there and works.

[cowpuc]

My gut tells me the issue is RLU related if the 87 MK2's have one.  I would start my diagnostics with a volt/ohm meter there if it was one of my MK1's. Should be able to diagnose the high/low beam switch from that point easier than tearing the switch apart, maybe get your hands on a schematic and see.. 

[Pasta Burner]

I don’t remember the specifics but the headlight circuit runs through the start switch.  I had a light and start malfunction there.  Ended up rebuilding the switch which I really should replace.

when the start switch is depressed the circuit to the headlight opens to kill the light when cranking.

Edited July 6, 2022 by Pasta Burner

[Max]

Nice explanation found here pucster. Never knew what RLU was or it's function. Found the 8 pin connector block to RLU. Jumpering might be a quicker test than taking switch apart to isolate trouble at this point? I'll give it a shot. Closer look at schematic shows head lamp indicator, high beam indicator, illumination control lamp and headlight leads (all of which are out) trace back to the RLU. 

https://www.venturerider.org/forum/topic/61834-location-and-access-to-the-reserve-lighting-unit-or-rlu/#comment-746566

 

[luvmy40]

While I can't rule out the RLU, I will second the start switch recommendation. When I lost the headlight on my '86, it was the start switch interupt contacts.

Edited July 6, 2022 by luvmy40

[Max]

Appreciated all the responses. Once again the brothers came thru!

Ok, I thought the bypass recommended would be a quicker test to eliminate the RLU which luck has it appears to be defective. Bypassed with jumpers as suggested in VerntureVet's link below. Upper/lower beams fully functional. Display 'light' indicator on CPU stays on after self check. Below is my rendition of a bypass mess, but it worked. Fortunately I have a spare 87' parts bike to salvage a spare RLU. Thanks again gents! 

https://www.venturerider.org/forum/topic/56239-reserve-lighting-unit-rsu-bypass-1988-venture-royale/#comment-671700

(side note: The 3 pig tail connection posted by VerntureVet that read green/white was green/red on this 87'. minor detail I thought worth mentioning)

 

[RDawson]

Ain’t it cool how much time and headache $12 saves? The gurus came thru again 😂

[cowpuc]

17 hours ago, RDawson said:

Ain’t it cool how much time and headache $12 saves? The gurus came thru again 😂

and the REALLY cool thing about those lop eared guru varmints around here is they really truly don't mind us pea brains jumping in and tossing out idea's no matter how far out they seem.. Matter of fact,, they invite it. This group of gear heads is by far, the greatest group of lop eared wrench spinning, eat to ride ride to eat, fun loving varmints the net has ever seen! Wanna see something really cool @Max, if we ever do get back to the good ol times of VR Maintenance Days and you have never been to one bring your bike with something broken and stand back and watch how quickly it comes apart and goes back together. I watched a dash come apart in less than 5 minutes one time at a MD and go back together in less time than it took them guru's to take it apart!! A job that easily would have taken me 2 hours to complete,, it was AMAZING!! Personally, I actually always enjoyed being an innocent bystander at such events at such occasions (see vid). A special THANK YOU to @ragtop69gs and Jeanie for this one! 

 

[Max]

Oh wait there's more ... Thought the trouble was suit cased yesterday. This morning, removed RLU, cleaned what looked like slightly corroded contacts, thin layer dielectric grease and reconnected RLU and heh, lights work. End of problem right? Tried lights and ... no lights. Long story short, poked around switches and found the Start switch intermittently binding when thumb released. That was a lucky find! (thanks for suggesting that direction in earlier replies) Can actually simulate the problem by starting bike and Start switch will stick eventually. So, maybe the start switch and RLU combo? In any case, I can deal with binding switch for now by pulling out switch button when it sticks. 

Would a micro shot of FluidFilm or WD40 into the housing that the start switch rides on be recommended to loosen binding or just do a rebuild of the entire assembly? Thinking lube might compound problems down the road?

 

Note, found RLU access fairly easy. Removed windshield and upper CPU housing. There are 2 of 4 housing Philips screws that can't be reached with a regular screwdriver. Removed both turn signal housings to access the 2 screws on both sides.

           

[Max]

19 hours ago, RDawson said:

Ain’t it cool how much time and headache $12 saves? The gurus came thru again 😂

Agree and well said Ronnie. I`m sure this ol`87 would have hit the boneyard years ago without our gurus. Thanks again all` !

[RDawson]

44 minutes ago, Max said:

Agree and well said Ronnie. I`m sure this ol`87 would have hit the boneyard years ago without our gurus. Thanks again all` !

My 86 is the same story. I found this site by googling problems with it. After multiple problems every search brought me here, I felt a little guilty for the free help and joined. Best thing I ever did, met new friends I didn’t know I had and enjoy the get togethers. 

[Max]

1 hour ago, Max said:

Would a micro shot of FluidFilm or WD40 into the housing that the start switch rides on be recommended to loosen binding or just do a rebuild of the entire assembly? Thinking lube might compound problems down the road?

Forged ahead and gave the Start button gap a small dose of Fluid Film as it is the bottom switch., worked it, now smooth operation, end of binding and sticking. Can actually feel some sort of switch inside housing operate. I will disassemble housing end of season and rectify whatever needs a tweek. .

[luvmy40]

14 minutes ago, Max said:

Forged ahead and gave the Start button gap a small dose of Fluid Film as it is the bottom switch., worked it, now smooth operation, end of binding and sticking. Can actually feel some sort of switch inside housing operate. I will disassemble housing end of season and rectify whatever needs a tweek. .

Be very, Very, VERY careful when taking that switch apart!!!! Lots of very small "stuff" that will go SPROING!!! IIRC, I had to actually fabricate some copper contacts when I had my issue, 'cause I wasn't VERY CAREFUL!!!

[Marcarl]

34 minutes ago, luvmy40 said:

Be very, Very, VERY careful when taking that switch apart!!!! Lots of very small "stuff" that will go SPROING!!! IIRC, I had to actually fabricate some copper contacts when I had my issue, 'cause I wasn't VERY CAREFUL!!!

Yep, know all about that. Less than 5 minutes to get things lost, whole job about 4 hrs. 3hrs 45 min on hands and knees checking out what was on the floor or elsewhere.

[Max]

43 minutes ago, luvmy40 said:

Be very, Very, VERY careful when taking that switch apart!!!! Lots of very small "stuff" that will go SPROING!!! IIRC, I had to actually fabricate some copper contacts when I had my issue, 'cause I wasn't VERY CAREFUL!!!

 

 

10 minutes ago, Marcarl said:

Yep, know all about that. Less than 5 minutes to get things lost, whole job about 4 hrs. 3hrs 45 min on hands and knees checking out what was on the floor or elsewhere.

 Or maybe not to be disassembled, till necessary :))   With Start, Cancel, Cruise and Engine Stop switch clusters in that small housing, a shot of lube seemed the way to go. One of those `don`t fix what`s working`? Appreciate the heads up! 

[cowpuc]

32 minutes ago, Max said:

 

 

 Or maybe not to be disassembled, till necessary :))   With Start, Cancel, Cruise and Engine Stop switch clusters in that small housing, a shot of lube seemed the way to go. One of those `don`t fix what`s working`? Appreciate the heads up! 

BINGO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!  times infinity and beyond... 

[Marcarl]

1 hour ago, Max said:

 

 

 Or maybe not to be disassembled, till necessary :))   With Start, Cancel, Cruise and Engine Stop switch clusters in that small housing, a shot of lube seemed the way to go. One of those `don`t fix what`s working`? Appreciate the heads up! 

Actually there is not a lot in there, but without 1 stupid little spring, it's all kind of useless.

[Pasta Burner]

Am I becoming a GuRu? 🤓 The real Gurus beat me to warning you about taking apart that switch!  A spring and a bearing ball and poof!  Once you spend the time finding the parts that you didn’t even knew flew out, prepare to spend time imagining how it goes back together 🤔 then look for more missing parts.  As I said earlier I really should replace mine, and as you said don’t disassemble until necessary.  She’s a little rough superficially but when I had the internals apart mostly the guts were intact.  Also if memory serves correct I added a coat of dielectric grease to the contacts but I know for sure fluid film to the moving pieces.  And no, no matter what I can’t get the sleeving to stay in the housing.

[Max]

Just a bit of a follow-up, after a few hundred km and quite a few starts', switch is functioning as should and all electrics are good. 👍