amazonphil
New member
- Joined
- Oct 8, 2017
my headlights and all the lights flicker, even instrument lights.
I figured it had to be an alternator problem, but swapped the alternator from my /90 740
it made no difference. voltage is 12.75 at battery. 14 V when running, so it's charging.
it seems to have DC with ripple current. I know with most power supples one would rectify and then smooth out the ripples with capacitors,and an alternator does ut out AC power but on cars I assume the battery acts to smooth the AC ripple from the alternator, and that it's rectified by a diode within the alternator,
I tried using jumper cables to see if connecting the ground terminal to the engine or alternator housing would prove a bad connection but the flickering continued.
i tried connecting a hot jumper tot he main output terminal on the alternator, still no difference..
the lights arent' going out they are flickering at a fairly high frequency but as far as I can tell with my meter the voltage is pretty constant.
I checked for bad grounds to the engine or to the headlights and taillights , cleaned the fuse near the distributor and the hot wire terminal strip, no difference..
does anyone know how to troubleshoot this further or has anyone seen similar issues?
it runs ok but hte flickering lights are annoying and I know something isn't right here. its kind of driving me nuts.
when driving, the flickering does not seem to change or coincide with engine speed, and since I replaced the alternator already and it hasn't changed it must be from somethign else, But what?
bad fuel pump causing ripple maybe? I'm stuck.
any help or suggestions would be appreciated,
Thanks,
Phil
I figured it had to be an alternator problem, but swapped the alternator from my /90 740
it made no difference. voltage is 12.75 at battery. 14 V when running, so it's charging.
it seems to have DC with ripple current. I know with most power supples one would rectify and then smooth out the ripples with capacitors,and an alternator does ut out AC power but on cars I assume the battery acts to smooth the AC ripple from the alternator, and that it's rectified by a diode within the alternator,
I tried using jumper cables to see if connecting the ground terminal to the engine or alternator housing would prove a bad connection but the flickering continued.
i tried connecting a hot jumper tot he main output terminal on the alternator, still no difference..
the lights arent' going out they are flickering at a fairly high frequency but as far as I can tell with my meter the voltage is pretty constant.
I checked for bad grounds to the engine or to the headlights and taillights , cleaned the fuse near the distributor and the hot wire terminal strip, no difference..
does anyone know how to troubleshoot this further or has anyone seen similar issues?
it runs ok but hte flickering lights are annoying and I know something isn't right here. its kind of driving me nuts.
when driving, the flickering does not seem to change or coincide with engine speed, and since I replaced the alternator already and it hasn't changed it must be from somethign else, But what?
bad fuel pump causing ripple maybe? I'm stuck.
any help or suggestions would be appreciated,
Thanks,
Phil