Joseph Posted April 20, 2023 Share Posted April 20, 2023 (edited) given these following facts regarding a right handlebar light switch : • 12 V feed to input wire is present • switch continuity between the 12V input and output wires is tested ok when you switch the switch on yet no power through the output wire when the switch is put on ? Edited April 20, 2023 by Joseph Quote Link to comment
TonyGee Posted April 20, 2023 Share Posted April 20, 2023 (edited) that seams odd I think what I would do is strip the switch and check/clean the little copper sliders first just to rule them out. Edited April 20, 2023 by TonyGee Quote Link to comment
Rijko Posted April 20, 2023 Share Posted April 20, 2023 (edited) 5 hours ago, Joseph said: given these following facts regarding a right handlebar light switch : • 12 V feed to input wire is present • switch continuity between the 12V input and output wires is tested ok when you switch the switch on yet no power through the output wire when the switch is put on ? Occam's razor .. if fact 1 (12V input is present) is correct and fact 3 (no output) is correct ... fact nr. 2 should be questioned. +1 on what Tony said Edited April 20, 2023 by Rijko Quote Link to comment
Rijko Posted April 20, 2023 Share Posted April 20, 2023 (edited) I recently read a nice explanation of the culprit in trusting a continuity test. Say you have a wire with all strands but 1 broken. A continuity test would be succesful, but no way that 1 strand would be able to carry enough amps to power something big. Only a load test would show the wire to be the problem. You just did a ok continuity test but the load test failed ... Edited April 20, 2023 by Rijko 4 Quote Link to comment
Joseph Posted April 21, 2023 Author Share Posted April 21, 2023 @Rijkogood points i'll check that out. Quote Link to comment
Devilman Posted April 21, 2023 Share Posted April 21, 2023 (edited) 21 hours ago, Rijko said: I recently read a nice explanation of the culprit in trusting a continuity test. Say you have a wire with all strands but 1 broken. A continuity test would be succesful, but no way that 1 strand would be able to carry enough amps to power something big. Only a load test would show the wire to be the problem. You just did a ok continuity test but the load test failed ... Very much agree with this. Testing continuity using a load can be a very effective way of finding a problem. Rather than using a multimeter, use a (fused) supply from the battery, a bulb and route the wire you're testing to earth. Can use a variety of bulbs to simulate different loads. 60w Headlamp bulb is going to be around 4.5-5A depending on battery voltage. 21w Brake Light bulb is good to simulate a 1.8(ish) amp draw, etc.. Edited April 21, 2023 by Devilman 4 Quote Link to comment
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