have been doing some continuity tests on my my ignition switch (cb400f) not getting any power to the brown wire, or the brown/white wire. with the switch in the on position I have continuity between the red wire terminal and the black wire terminal. but no continuity between red and brown terminals or red and brown/white terminals. with the switch in the park position I have continuity between the red and brown terminals only. I picked up a new ignition switch and it tested the same. cant figure this out. I am not getting any power to tail light in the on position only in the park position. any idea's
ignition switch test's
- Thread starter palerider
- Start date
neevo
Over 1,000 Posts
How about testing the voltage across the fuse?
Going from memory the rear light is on a fuse when the ignition is live, unless you're referring to no voltage across the switch at all. In which case I've got no idea other than a buggered switch.
Have you got a wiring diagram?
Going from memory the rear light is on a fuse when the ignition is live, unless you're referring to no voltage across the switch at all. In which case I've got no idea other than a buggered switch.
Have you got a wiring diagram?
neevo
Over 1,000 Posts
In RUN you should be getting the following readings:
Red to Black: infinity ohms
Brown to Brown/White tracer: infinity ohms
These 2 sets shouldn't have any connection between them though.
In PA you should get:
Red to Brown: infinity ohms
This is in line with the readings you're getting from the ignition switch so there isn't a problem there.
The problem is more likely on the TL1 circuit Brown/White tracer. Test the continuity between the Br/W wire at the ignition and the bulbs in the tacho or speedo which are also Br/W. Report back.
Next test the continuity between the Br/W wire in the ignition and the 7A fuse for the rear light (probably bottom one), Br/W believe it or not.. Report back.
Red to Black: infinity ohms
Brown to Brown/White tracer: infinity ohms
These 2 sets shouldn't have any connection between them though.
In PA you should get:
Red to Brown: infinity ohms
This is in line with the readings you're getting from the ignition switch so there isn't a problem there.
The problem is more likely on the TL1 circuit Brown/White tracer. Test the continuity between the Br/W wire at the ignition and the bulbs in the tacho or speedo which are also Br/W. Report back.
Next test the continuity between the Br/W wire in the ignition and the 7A fuse for the rear light (probably bottom one), Br/W believe it or not.. Report back.
ok did all tests you had mentioned and have continuity in all, i am still thinking when I turn ignition switch to the run position with battery hooked up test light should show power on the brown and brown/white terminals, could a short later in the circuit some how affect this? THANKS m
neevo
Over 1,000 Posts
All those tests indicate the ignition switch is good and the wiring up to the fuse is also good. I assume the dash lights come on ok with the ignition in RUN and PA? I also assume you're using a tester and your checking resistance across each part?
Yeah you're right, a short later in the circuit is probably affecting the rear light.
Test across the fuse itself and make sure that its ok. I think there can be occasions when the fuse tests ok but then under load fails. If you're uncertain about the fuse or if its old replace it.
Next test the Brown/Blue tracer coming out of the fuse with the same wire in the headlight bucket. There should be a Br/B wire plugged into it. Unplug it if there is and test both sides, one should have continuity the other shouldn't.
After that test the Br/B wire that comes out of the wire you just tested and trace it back. It should join up with an earth feed where there are 4 black wires connected (the Br/B changes to Black somewhere along the line). Test between the Br/B in the headlight bucket and that 4 way black joint. Report back on all.
Yeah you're right, a short later in the circuit is probably affecting the rear light.
Test across the fuse itself and make sure that its ok. I think there can be occasions when the fuse tests ok but then under load fails. If you're uncertain about the fuse or if its old replace it.
Next test the Brown/Blue tracer coming out of the fuse with the same wire in the headlight bucket. There should be a Br/B wire plugged into it. Unplug it if there is and test both sides, one should have continuity the other shouldn't.
After that test the Br/B wire that comes out of the wire you just tested and trace it back. It should join up with an earth feed where there are 4 black wires connected (the Br/B changes to Black somewhere along the line). Test between the Br/B in the headlight bucket and that 4 way black joint. Report back on all.
I am not getting power to dash lights, but do have continuity from switch to tac light bulbs, checked bulbs they are good. will try the other tests later tonight. what I cant understand is the ignition switch is early in the system, its getting power on the black wire terminal (headlight) on run position therefore should I not have power on the brown and brown/white terminal as well?
neevo
Over 1,000 Posts
No not on run as power is fed via a lengthy run from TL1 which is probably why you're getting confused. It's not as simple as looking for power when you flick the switch.
Do the other tests and report back, that will help a bunch to identify where the issue lies.
What setting do you have your multimeter on?
Do the other tests and report back, that will help a bunch to identify where the issue lies.
What setting do you have your multimeter on?
ok have tested across the fuse and it is good, there is no brown/ blue tracer in the headlight bucket but did find a solid brown wire with nothing hooked up to it and it did have continuity with the brown/blue coming out of the fuse box. I found one joint with four black wires in the headlight bucket it had a red wire connected to it as well leading to another joint with three blue wires one which went to the headlight socket.
thanks neevo just had a good cb400f diagram enlarged, haven't fixed it yet but i think i am getting closer. was trying to figure out where the voltage entered the circuit. after studying the diagram I believe its from the brown/ blue wire I found unplugged in the headlight bucket. will jump some switched power to it and see what happens.
