| jerry weiser | -- 08-21-2011 @ 8:39 AM |
|
car is 36 coupe. installed alt. reversed poles,etc. runs good, charges good. when shut off, battery drains and alt gets real hot. sent alt to manufacturer, sez its good, but it was tested on a stand, not w/ a battery hookad up and shut off. with car off, battery cables spark. mfg. sez this is normal w/ alt. help, any experience w/ alt coversions? weezer
|
|
| supereal | -- 08-21-2011 @ 11:48 AM |
|
I'd bet on a bad diode in the trio. The diodes both turn the AC produced by the alternator into DC for the system, but also act as a "check valve" to prevent back flow from the battery when the engine is off. To confirm that diagnosis, disconnect the output wire from the alternator. If it sparks to the alternator post, you have found the problem, and it is certain your battery will not run down if the wire is left disconnected. This is not an unusual problem with alternators converted to "one wire". Left unrepaired, your battery will be ruined, if it isn't already.
|
|
| jerry weiser | -- 08-21-2011 @ 12:31 PM |
|
thanks for your interest. im guessing the output side is to the battery. where is the alternator post to check for sparking? it wistles at low rpm too. weezer
|
|
| supereal | -- 08-21-2011 @ 12:41 PM |
|
Whistling is usually an indication of a failed diode. The output post should be on the back (firewall) side of the alternator. In the case of a one wire unit, it is the only wire connected. You mention "reversed poles", which I assume you now have a negative ground. Are you sure that your alternator was set up for that configuration? Most 6 volt alternators I've seen are meant for positive ground. If not, it could account for your problems. I should add that I am not impressed with one wire alternators on flathead Fords. I have one on my '47, and I've had to fabricate a smaller pulley to get it running fast enough to keep up with demand, and to get it to "kick on" without overrevving the engine at first startup.
|
|
| jerry weiser | -- 08-21-2011 @ 12:50 PM |
|
there are 2 wires. one to ig switch, one to battery. if i disconect batt wire, no problem w/ discharge or heat. is that output? where is alt terminal. purchased from fith av. supply weezer
|
|
| jerry weiser | -- 08-21-2011 @ 1:04 PM |
|
yes, batt wire sparks at terminal it was removed from. seems like mfg would know this. ive talked to him 8 or 9 times. wouldnt a bad part show up on bench test? weezer
|
|
| jerry weiser | -- 08-21-2011 @ 1:21 PM |
|
yes, car is now neg ground. switched battery and elect fuel pump. weezer
|
|
| supereal | -- 08-21-2011 @ 8:18 PM |
|
If you have two wires to the alternator, the one from the ignition switch actually turns the alternator on when power is applied, which is different from the more common one wire type that depends on residual magnetism to start. Check the wire to the ignition switch. I suspect that it is staying "hot" when the ignition switch is off, perhaps not properly connected to a terminal that is off when the engine is turned off, or the switch is faulty. In either case, it will run the battery down quickly.
|
|
| jerry weiser | -- 08-23-2011 @ 6:36 AM |
|
yes, you are right. i was hooked to the hot side of ignition switch. thank you all. weezer
|
|
| supereal | -- 08-23-2011 @ 10:37 AM |
|
Good news, Jerry. If I had known you had a two wire alternator, we could have helped sooner. To those contemplating installing an alternator, the two wire type is a much better choice than the one-wire variety because they will come on without racing the engine.
|
|
| EFV-8 Club Forum : | https://www.earlyfordv8.org/forum |
| Topic: | https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=3633 |