Raider 2 #1 Posted December 22, 2009 My 312-8 came with burned out headlights so I replaced them for plowing at night. Within a half hour both were burned out again. (These were cheap Chinese plastic headlights, the terminal even broke off one of them.) Before I put another set into the tractor I want to make sure the electrical circuit is working right. Here's what I've got: The lights will only come on while the engine is running, is this right? I am getting 12.5 volts at the battery engine off and 14 volts engine on, this seems normal to me. I put my meters on the back of the bulbs with the engine running and light switch on and the digital jumps around too much, the analog shows steady 14 volts AC, nothing on DC, is this right? I think the tractor is pretty much original except for a new replacement Kohler. Everything is in very good condition. Thanks :notworthy: Share this post Link to post Share on other sites
rwilson 128 #2 Posted December 22, 2009 it sounds like you have too much voltage going to the lights. maybe the voltage regulator is bad. someone with more expierience with electrical will be along shortly. Share this post Link to post Share on other sites
TT-(Moderator) 1,162 #3 Posted December 22, 2009 The 85/86 312 models with the K-301 engines use a dual-circuit alternator. One section of it is diode rectified and produces roughly 3 amps of "modified" DC power to maintain the charge in the battery (depleted by the ignition coil) and the other section produces 70 watts of AC power at approximately 14/15 volts (@ WOT) to power the lights. You should probably try a pair of good sealed beams (4411-1 is the part number) with the current AC system first before attempting to feed the lights directly off of the battery power. If you hook the lighting circuit up to the battery, you will be using more power than the charging system is capable of replacing - but only over a very long period when operating with the lights on. P.S. > don't try to find the rectifier/regulator on these models 'cause there isn't one. :notworthy: Share this post Link to post Share on other sites
Raider 2 #4 Posted December 22, 2009 Thankyou so much for the explanation. It sounds like everything is working like it is supposed to then and I just need to get myself a good set of lights. Merry Christmas! :notworthy: Share this post Link to post Share on other sites
Raider 2 #5 Posted December 23, 2009 I put in two new sealed beams tonight and plowed a couple of driveways out. The lights worked great! Share this post Link to post Share on other sites
TT-(Moderator) 1,162 #6 Posted December 23, 2009 Excellent! :notworthy: Share this post Link to post Share on other sites
