When Lights Just Don't Wanna Come On
Posted: Mon Sep 29, 2014 6:27 pm
Hopefully this will help someone down the road who isn't trained in electronics - cause I am and it still took me a couple of hours...
After doing all the paint and "prettying" of the beast, it was time for the first run-up. Kicked it over 3 or four times, then remembered to put the ignition on (my crowd was amused by this, of course). Next kick up she fired. Life... Fuel - good. Oil - meh (see my other post). Electrical - turn sigs okay, then...
I have modified the control switch on my project to allow the lights to be turned off (stock in Canada is running lights mandatory - so shhhh). When I hit the switch to turn on the headlight it went on - like a super nova! One flash and nothing. Hmmm... Off goes the headlight switch, but now the turn sigs are iffy. They look like they just don't wanna come on. One terribly weak flash, followed by regular but very weak flashing.
Before I go further I should note that I've got a large capacitor instead of a battery, so what goes here doesn't necessarily apply with a battery...
Headlight is now garbage - no low beam. So I check voltage - 14.4V. Great. Try turn sigs - same half-ass falshing. Check voltage with lights on 6V. Strange... Lights off and back to 14.4V. So I start chasing. Where is the partial short. What in my turn sig lines is killing the voltage. And... nada. Everything looks fine.
Then I have my a-ha moment. Back to first year electronics. If I don't have current capacity - it's cause I ain't making it. And where does the charge come from - the rectifier! After checking the legs it turns out it was only rectifying half-wave. One leg was shorted. Half-wave rectification will still get to 14.4V when there is no draw, but with lights on it's only charging half as fast.
Ripped the rectifier and regulator out and got a tympanium combined unit. Works like charm. Everything is nice and bright - excpet that I haven't got my new headlight yet... So we'll see how that goes.
If you had a battery, like most do, this would have presented itself dfferently. You may not have known for some time. It would have charged the battery (slowly) when everything was off, but would have drained it when lights were on. Eventually you'd have a dead battery and no idea why.
Perhaps it would be obvious to some, but I was happy with myself for not just swapping parts till it went away, but for diagnosing it down to one leg on the rectifier. Now if I can just stop stripping bolts on the oil pump (like I said, see my other post).
After doing all the paint and "prettying" of the beast, it was time for the first run-up. Kicked it over 3 or four times, then remembered to put the ignition on (my crowd was amused by this, of course). Next kick up she fired. Life... Fuel - good. Oil - meh (see my other post). Electrical - turn sigs okay, then...
I have modified the control switch on my project to allow the lights to be turned off (stock in Canada is running lights mandatory - so shhhh). When I hit the switch to turn on the headlight it went on - like a super nova! One flash and nothing. Hmmm... Off goes the headlight switch, but now the turn sigs are iffy. They look like they just don't wanna come on. One terribly weak flash, followed by regular but very weak flashing.
Before I go further I should note that I've got a large capacitor instead of a battery, so what goes here doesn't necessarily apply with a battery...
Headlight is now garbage - no low beam. So I check voltage - 14.4V. Great. Try turn sigs - same half-ass falshing. Check voltage with lights on 6V. Strange... Lights off and back to 14.4V. So I start chasing. Where is the partial short. What in my turn sig lines is killing the voltage. And... nada. Everything looks fine.
Then I have my a-ha moment. Back to first year electronics. If I don't have current capacity - it's cause I ain't making it. And where does the charge come from - the rectifier! After checking the legs it turns out it was only rectifying half-wave. One leg was shorted. Half-wave rectification will still get to 14.4V when there is no draw, but with lights on it's only charging half as fast.
Ripped the rectifier and regulator out and got a tympanium combined unit. Works like charm. Everything is nice and bright - excpet that I haven't got my new headlight yet... So we'll see how that goes.
If you had a battery, like most do, this would have presented itself dfferently. You may not have known for some time. It would have charged the battery (slowly) when everything was off, but would have drained it when lights were on. Eventually you'd have a dead battery and no idea why.
Perhaps it would be obvious to some, but I was happy with myself for not just swapping parts till it went away, but for diagnosing it down to one leg on the rectifier. Now if I can just stop stripping bolts on the oil pump (like I said, see my other post).
