Battery Terminal Wires Hot

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elefantrider

elefantrider

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I am getting a hot-to-the-touch wires when the key switch is on ignition+lights, and the engine not running. Any idea on what could cause this?


The battery is good but the headlamp pilot light is weak when the engine is off.
 
Sounds like a short to ground. Do you have a fuse in line? I would start by removing all the bulbs in the headlight and taillight and see if the terminal wire still gets hot. If not then install the bulbs one at a time until they do. Then check all the wiring in the circuit causing the problem.

If you suspect the pilot lamp, I would start with that one.
 
Yes I have a fuse in line. Sometimes when the bike is running, switching on lights position would kill the engine if the battery is low.
I will try removing all bulbs today and see if I can determine the cause.

This is a '71 and I have 3 position lever switch on both hand lever switch clusters. Currently in the middle position on both.
The bucket toggle is in the middle (straight up) position also.

Engine not running, the Pilot light should operate when the key switch is in the lights on (2 forward), and 1 back parking position, correct?
Headlamp beam should operate only when the engine is on, correct?
 
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OK. Then, which key position(s) is Pilot and which is Headlamp beam?
And what is the toggle on the bucket for?

It has been a while since I've messed with a Commando and I've forgot.
 
elefantrider said:
OK. Then, which key position(s) is Pilot and which is Headlamp beam?
And what is the toggle on the bucket for?
Click to expand...

Battery Terminal Wires Hot


The pilot and headlamp should both come on at "Ignition and Lights".
1971-on, the two position headlamp toggle allows for the headlamp only to be switched OFF (or ON) independently when the key is at the Ignition and Lights position.

The headlamp should not come on at the Parking with Lights position.
 
Bad fuse holder, wire conducting heat from the high resistance fault.
 
L.A.B. said:
Battery Terminal Wires Hot


1971-on, the two position headlamp toggle allows for the headlamp only to be switched OFF (or ON) independently when the key is at the Ignition and Lights position.
Click to expand...

Many thanks! Headlamp bucket toggle straight up is headlamp on and to the right is headlamp off?
 
concours said:
Bad fuse holder, wire conducting heat from the high resistance fault.
Click to expand...


Thanks, I did not think of that. It has an original Lucas type spring fuse holder. Will test it.
Do these go bad often? I have a mini blade type on one of my other bikes. Probably more reliable without the spring.
 
elefantrider said:
Thanks, I did not think of that. It has an original Lucas type spring fuse holder. Will test it.
Do these go bad often? I have a mini blade type on one of my other bikes. Probably more reliable without the spring.
Click to expand...
Yes they do. Several strands of wire can break, or weak spring
 
Found and repaired several potential causes of the hot wires.

1. Rear brake wires were very loose on the switch.
2. Burnt out headlamp bulb.
3. Pilot light receptacle shorting out against headlamp bucket (It's a small SS type bucket, not much space in there). Probable main cause.


Now wanting to eliminate other potential sources of future electrical problems.
Is this the correct harness switch routing, over the frame, sandwiched between it and the cover? Seems like a bad idea.
It has already chafed the tape.
 

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Where does this grommet go? I cannot seem to find a place for it. There is already a grommet on the inner primary cover.
 

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That looks like the grommet that goes into the frame brace plate where the harness passes through.
 
elefantrider said:
Now wanting to eliminate other potential sources of future electrical problems.
Is this the correct harness switch routing, over the frame, sandwiched between it and the cover? Seems like a bad idea.
It has already chafed the tape.
Click to expand...

The harness is usually routed beneath the frame rail.
 
Ron L said:
The harness is usually routed beneath the frame rail.
Click to expand...

I routed it behind the frame tube, in between the air cleaner switch bracket and the screen. Unsure if correct, but that is the only way it wouldn't touch anything.
 
Lights all working. Wires not hot anymore.

Highbeam only works on right push button, not paddle lever?

Right side paddle lever UP turns on the headlamp.
Paddle down dis-activates the headlamp.

Bucket switch turns on/off headlamp.
 
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