« previous next »
Pages: [1]   Go Down

Author Topic: 71 cb750 on off switch is working backwards  (Read 5637 times)

0 Members and 1 Guest are viewing this topic.

Offline painters cafe

  • Full Member
  • *
  • Posts: 45
71 cb750 on off switch is working backwards
« on: April 24, 2011, 05:20:02 PM »
theres a black wire and a black with white wire. they are pluged in but why when the red switch is off it has spark? and when it's on it dont???
Logged
1972 cb750p 1970 cb750 chopper 1976 ss750 1974 cb750 1975 cb750 1972 cb750 1974 750 72 cb750 1971 cb750 1976 cb750 cafe 1977 cb750 1972 cb350-4 1973 cb350-4 1972 cb350 1974 cb350 1970 cl175 1970 cb450 1972 cl450 1972 cl350 1972 cb550 2- 1974 cb360 1971 cl125 1975 cb125 some of the hondas i had

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: 71 cb750 on off switch is working backwards
« Reply #1 on: April 24, 2011, 06:29:40 PM »
Try reversing the wires.....
Logged
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline painters cafe

  • Full Member
  • *
  • Posts: 45
Re: 71 cb750 on off switch is working backwards
« Reply #2 on: April 25, 2011, 02:04:47 AM »
i did that same thing
Logged
1972 cb750p 1970 cb750 chopper 1976 ss750 1974 cb750 1975 cb750 1972 cb750 1974 750 72 cb750 1971 cb750 1976 cb750 cafe 1977 cb750 1972 cb350-4 1973 cb350-4 1972 cb350 1974 cb350 1970 cl175 1970 cb450 1972 cl450 1972 cl350 1972 cb550 2- 1974 cb360 1971 cl125 1975 cb125 some of the hondas i had

Offline SohRon

  • She laughs 'til she cries when they call me an
  • Expert
  • ****
  • Posts: 946
Re: 71 cb750 on off switch is working backwards
« Reply #3 on: April 25, 2011, 05:50:30 AM »
If by the "red" switch you mean the kill switch, switching wires won't (or shouldn't) make a difference. The kill switch has two contacts in the center position, none on either side (this is a later switch, but the kill switches are all the same).



If you're getting power in the off position, and nothing in the center, it sounds like a rebuild is in order.
Logged
"He slipped back down the alley with some roly-poly little bat-faced girl..."

Assembling my '74 CB550: http://forums.sohc4.net/index.php?topic=86697.0
Assembly of the Right-hand Switch (a rebuilder's guide):  http://forums.sohc4.net/index.php?topic=80532.0
Installing stock 4X4 exhaust: CB500-CB550 K: http://forums.sohc4.net/index.php?topic=82323.0
CB550 Assembly Manual: http://forums.sohc4.net/index.php/topic,151576.0.html

Offline nayto550

  • Hot Shot
  • ***
  • Posts: 277
Re: 71 cb750 on off switch is working backwards
« Reply #4 on: April 25, 2011, 05:50:52 AM »
This shouldn't even be possible, regardless of the wires being reversed or not.
I would suspect the switch itself first.  Grab yourself an ohmmeter and make sure the switch is closed in the "run" position and open in the "off" position.
Logged
1976 CB550F
1976 CB750F - in resurrection process
1988 HD FLHS

Offline painters cafe

  • Full Member
  • *
  • Posts: 45
Re: 71 cb750 on off switch is working backwards
« Reply #5 on: April 25, 2011, 08:45:18 AM »
Ok ill do that. Yep it runs when it is off on kills it

Logged
1972 cb750p 1970 cb750 chopper 1976 ss750 1974 cb750 1975 cb750 1972 cb750 1974 750 72 cb750 1971 cb750 1976 cb750 cafe 1977 cb750 1972 cb350-4 1973 cb350-4 1972 cb350 1974 cb350 1970 cl175 1970 cb450 1972 cl450 1972 cl350 1972 cb550 2- 1974 cb360 1971 cl125 1975 cb125 some of the hondas i had

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: 71 cb750 on off switch is working backwards
« Reply #6 on: April 25, 2011, 04:21:27 PM »
Quote from: nayto550 on April 25, 2011, 05:50:52 AM
This shouldn't even be possible, regardless of the wires being reversed or not.
I would suspect the switch itself first.  Grab yourself an ohmmeter and make sure the switch is closed in the "run" position and open in the "off" position.

Why wouldn't reversing the polarity work ?, it is only a simple switch.? I am not too sure the switch is broken if it is working exactly the opposite.....?
Logged
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline painters cafe

  • Full Member
  • *
  • Posts: 45
Re: 71 cb750 on off switch is working backwards
« Reply #7 on: April 25, 2011, 04:49:08 PM »
it must be down the line black with white is at coils black is hot??? something must be cross
Logged
1972 cb750p 1970 cb750 chopper 1976 ss750 1974 cb750 1975 cb750 1972 cb750 1974 750 72 cb750 1971 cb750 1976 cb750 cafe 1977 cb750 1972 cb350-4 1973 cb350-4 1972 cb350 1974 cb350 1970 cl175 1970 cb450 1972 cl450 1972 cl350 1972 cb550 2- 1974 cb360 1971 cl125 1975 cb125 some of the hondas i had

Offline CBDee

  • Enthusiast
  • **
  • Posts: 116
Re: 71 cb750 on off switch is working backwards
« Reply #8 on: April 25, 2011, 05:47:11 PM »
Sounds like its broken to me. Take it apart and see what gives.
« Last Edit: April 25, 2011, 05:49:58 PM by CBDee »
Logged
Sent from my Old & Busted PC using Myindexfingers

Offline nayto550

  • Hot Shot
  • ***
  • Posts: 277
Re: 71 cb750 on off switch is working backwards
« Reply #9 on: April 25, 2011, 05:50:41 PM »
Quote from: Retro Rocket on April 25, 2011, 04:21:27 PM
Quote from: nayto550 on April 25, 2011, 05:50:52 AM
This shouldn't even be possible, regardless of the wires being reversed or not.
I would suspect the switch itself first.  Grab yourself an ohmmeter and make sure the switch is closed in the "run" position and open in the "off" position.

Why wouldn't reversing the polarity work ?, it is only a simple switch.? I am not too sure the switch is broken if it is working exactly the opposite.....?

Reversing the black/white and black wire won't work, because, as you said it is a simple switch.  Single circuit, in-line, off-on.  The only thing the switch does is cut the coils' line to power.  You can see in the wiring diagram that the switch won't care what direction it is placed in the circuit, it will still function the same.

Unless, of course, you start swapping wires with something other than the black and black/white. ;)
« Last Edit: April 25, 2011, 05:53:11 PM by nayto550 »
Logged
1976 CB550F
1976 CB750F - in resurrection process
1988 HD FLHS

Offline painters cafe

  • Full Member
  • *
  • Posts: 45
Re: 71 cb750 on off switch is working backwards
« Reply #10 on: April 25, 2011, 06:01:02 PM »
right i'm going out and take tank off look at coil wires black and white and pull switch apart.
Logged
1972 cb750p 1970 cb750 chopper 1976 ss750 1974 cb750 1975 cb750 1972 cb750 1974 750 72 cb750 1971 cb750 1976 cb750 cafe 1977 cb750 1972 cb350-4 1973 cb350-4 1972 cb350 1974 cb350 1970 cl175 1970 cb450 1972 cl450 1972 cl350 1972 cb550 2- 1974 cb360 1971 cl125 1975 cb125 some of the hondas i had

Offline phil71

  • Master
  • *****
  • Posts: 1,813
Re: 71 cb750 on off switch is working backwards
« Reply #11 on: April 25, 2011, 06:07:19 PM »
take the tank off? someone must've got at that switch. Someone's got an amazing pictorial of a switch rebuild on here. From what I can see, it look like you COULD put the contacts in the wrong holes, BUT, it would be Run/off/off, or off/off/run.
Logged

Offline hesselfuzz

  • Full Member
  • *
  • Posts: 66
Re: 71 cb750 on off switch is working backwards
« Reply #12 on: April 25, 2011, 09:44:21 PM »
What did you do to it before this started happening?
Logged
Moderation is a fatal thing, the only success is in excess.  -Oscar Wilde
73 CB750k
78 CB750ss
70 CB750k
06 Buell Ulysses

Offline painters cafe

  • Full Member
  • *
  • Posts: 45
Re: 71 cb750 on off switch is working backwards
« Reply #13 on: April 26, 2011, 04:58:21 AM »
take tank off wanted to look at wires better. The controls that was on the bike had the black and b/w together switch was broke. OK this is funny I grabed one more control that i had and took light off hooked up b/w wire and black and starter y/r and tryed it SAME switch worked the same ran only when it was off turn switch to on and kills the bike. it has to be down the line somewhere dont think it's the switch??? this is a fun one
Logged
1972 cb750p 1970 cb750 chopper 1976 ss750 1974 cb750 1975 cb750 1972 cb750 1974 750 72 cb750 1971 cb750 1976 cb750 cafe 1977 cb750 1972 cb350-4 1973 cb350-4 1972 cb350 1974 cb350 1970 cl175 1970 cb450 1972 cl450 1972 cl350 1972 cb550 2- 1974 cb360 1971 cl125 1975 cb125 some of the hondas i had

Offline nayto550

  • Hot Shot
  • ***
  • Posts: 277
Re: 71 cb750 on off switch is working backwards
« Reply #14 on: April 26, 2011, 06:47:06 PM »
Bumping this thread because I'm baffled by this and am curious what others' thoughts are.
 ??? ??? ???
Has to be a short to power somewhere between the switch and the coils.  But that doesn't explain why the kill switch cuts power in the "on" position.
Logged
1976 CB550F
1976 CB750F - in resurrection process
1988 HD FLHS

Offline SohRon

  • She laughs 'til she cries when they call me an
  • Expert
  • ****
  • Posts: 946
Re: 71 cb750 on off switch is working backwards
« Reply #15 on: April 26, 2011, 07:46:54 PM »
open up the headlight and by-pass the switch by disconnecting the leads running from it and jumpering the black/white main harness wire to a black lead. The bike should start and run normally. If it doesn't, you have wiring problems.

I've racked my brain and I just can't see how it could be the switch. The only electrical leads into it are the two contacts, and they're pretty well established right in the middle "run" position. I'll rerun a couple of pics to show how it goes together, but it would be real tough to get signal with the knob off the contacts.





 


Does this phenomenon occur at both "off" positions, or only one? Do all of the other electrical systems work correctly? Like the turn signals or brake lights"
« Last Edit: April 26, 2011, 08:09:44 PM by SohRon »
Logged
"He slipped back down the alley with some roly-poly little bat-faced girl..."

Assembling my '74 CB550: http://forums.sohc4.net/index.php?topic=86697.0
Assembly of the Right-hand Switch (a rebuilder's guide):  http://forums.sohc4.net/index.php?topic=80532.0
Installing stock 4X4 exhaust: CB500-CB550 K: http://forums.sohc4.net/index.php?topic=82323.0
CB550 Assembly Manual: http://forums.sohc4.net/index.php/topic,151576.0.html

Offline painters cafe

  • Full Member
  • *
  • Posts: 45
Re: 71 cb750 on off switch is working backwards
« Reply #16 on: April 27, 2011, 07:31:31 AM »
It work in both offs. All elec works but turns don't blink working on that one two
 
Logged
1972 cb750p 1970 cb750 chopper 1976 ss750 1974 cb750 1975 cb750 1972 cb750 1974 750 72 cb750 1971 cb750 1976 cb750 cafe 1977 cb750 1972 cb350-4 1973 cb350-4 1972 cb350 1974 cb350 1970 cl175 1970 cb450 1972 cl450 1972 cl350 1972 cb550 2- 1974 cb360 1971 cl125 1975 cb125 some of the hondas i had

Offline Silverback

  • Hot Shot
  • ***
  • Posts: 388
Re: 71 cb750 on off switch is working backwards
« Reply #17 on: April 27, 2011, 07:59:36 AM »
Quote from: rotortiller on April 27, 2011, 01:31:43 AM
Wiring issue, you are likely shorting the points out with the switch in the on position. Remember it sparks when the points open. Just a guess..........

rt

+1
Sounds like they are running a ground or something through the switch. When it's on the ground is shorting the coils/points. In the off position, the power to the coils is no longer grounded out. It seems like this configuration would blow fuses, but there are ways around that. Is this on a custom bike, or a stock bike? I have seen custom jobs with some of the craziest wiring configurations. My buddies Royal Enfield would only run if the run switch was off, turn signal switch pushed to the right and you were rubbing your belly with your left leg in the air. The PO said it was his security system.
Logged
Chris
"It's hard to define soul. You get it in art. You get it in music, and occasionally you get it in machinery."
78 CB750F racer
78 CB750F stock
75 CB750K Baby Blue Sold (She was a great bike!)
71 CB750K (rusty rod)
77 cb550F Sold :(  Bought it Back :)
Basket case 73 CB750, 77 CB750F (Building now)
01 Aprilia Falco
76 kz400
96 BMW K1100LT

Offline painters cafe

  • Full Member
  • *
  • Posts: 45
Re: 71 cb750 on off switch is working backwards
« Reply #18 on: April 27, 2011, 08:39:38 AM »
All stock 71 cb750
Logged
1972 cb750p 1970 cb750 chopper 1976 ss750 1974 cb750 1975 cb750 1972 cb750 1974 750 72 cb750 1971 cb750 1976 cb750 cafe 1977 cb750 1972 cb350-4 1973 cb350-4 1972 cb350 1974 cb350 1970 cl175 1970 cb450 1972 cl450 1972 cl350 1972 cb550 2- 1974 cb360 1971 cl125 1975 cb125 some of the hondas i had
Pages: [1]   Go Up
« previous next »