persof 14 #1 Posted May 10, 2010 My 1988 312-8 will not start. Turn the key and nothing? This has happened before and the last time I cleaned and tightened every electrical connection that I could find and the problem went away for a while. This time I drove my WH from it's place under the deck to the driveway for spring maint. Later when I tried to start "nothing". This time I removed all of the sheet metal to get at all of the switches and wiring. None of the indicator lamps work and I am not going to fix that. What switches can I remove? The tractor needs to start and the lights need to work nothing else. Thanks Franics Share this post Link to post Share on other sites
jpmcleod 4 #2 Posted May 10, 2010 I completely eliminated all my dash lights and wired it the same as all my others. The PO had butcher the wires so bad I jut rewired the while thing. Kept the volt meter operating and did away with all the other idiot lights. Too complicated but if you want yours original, then I would rewire the entire system. Check your PTO handle and make sure it is all the way back or it want start. What about your belt, did you get thet corrected? Share this post Link to post Share on other sites
truckin88 104 #3 Posted May 10, 2010 My 1988 312-8 will not start. Turn the key and nothing? This has happened before and the last time I cleaned and tightened every electrical connection that I could find and the problem went away for a while. This time I drove my WH from it's place under the deck to the driveway for spring maint. Later when I tried to start "nothing". This time I removed all of the sheet metal to get at all of the switches and wiring. None of the indicator lamps work and I am not going to fix that. What switches can I remove? The tractor needs to start and the lights need to work nothing else. Thanks Franics hold on did the indicator lamps work before? What service did you do to it? You say it drove out, you serviced it and it would not start again? Before you rip out wires, do the obvious, check and reseat fuses, put a meter on the battery, try to jump it even. Put in in neutral and try to start. Is there any noise or is it just dead? Even try jumping the solenoid with a screwdriver to see...process of elimination for the problem then hack up all the wires you want...though I am not sure why. Share this post Link to post Share on other sites
persof 14 #4 Posted May 10, 2010 The indicator lamps did not work when i bought this a year ago, maint performed: greese the zerks, check the oil level & check the air pressure. I did reseat the fuses, the battery is 12.5V. Which interlock switches can I eliminate ? Thanks Francis Share this post Link to post Share on other sites
persof 14 #5 Posted May 11, 2010 Please see the pics. The wire bundle from the indicator lamp pcb are routed between the steering wheel shaft and the metal plate it goes through; sounds like a recipie for a short at some point. What does that relay service? What is the yellow 20A fuse for? What is the blue 5A fuse for? What inter locks can I jumper out? Thanks Francis :D Share this post Link to post Share on other sites
Duff 206 #6 Posted May 11, 2010 Wow! I forgot I had my spare copy of the Parts and Service Manual for the 1988 300/400 series machines here at my office. So with wiring diagram in hand, here goes: The blue 5 amp fuse is actually 15 amp, I believe, and protects the circuit that supplies your head and tail lights. One of the wires coming from it should be dark green. The yellow 20 amp fuse is probably supposed to be a 25 amp fuse to protect the circuit feeding the starter solenoid. The PO may have changed it. Alternately, it could be the fuse (also 25 amp) that protects the hot feed from the battery to the Battery terminal on the ignition switch. The silver relay is part of the safety interlock system that feeds the starter solenoid. Now as to what swtiches can and cannot be bypassed, I'm going to have to defer to the experts here. I don't have quite enough experience reading wiring diagrams to cipher how all that mess goes together - sorry! [Disclaimer] Although I don't publicly advocate it [disclaimer], I removed all the warning lights and interlock switches on my 312-8's and rewired both machines from scratch with just the basics to have working tractors with head and tail lights. For what it may be worth, I noticed what appears to be heavy corrosion around the terminals for the pink wires in the connector coming from the engine (bottom picture, lower left corner). I think these are the feeds from the oil level switch and if one of these isn't making proper contact it may prevent the engine from starting. Others with more knowledge should chime in to help you out! Duff :D Share this post Link to post Share on other sites
IthacaJeff 151 #7 Posted May 11, 2010 Francis: From personal experience, I would check two things, both of which have been mentioned already. First, the PTO safety switch and the under seat switch. I've taped a pad underneath my seat to insure that the seat safety switch gets depressed. Second, check those fuse holders. My 310 won't start until I re-seat and press down on the 15amp fuse, as the fuse holder contacts are loose and corroded. One day I'll get around to replacing it. . . Jeff in Ithaca/Enfield Share this post Link to post Share on other sites
chesbaycruiser 82 #8 Posted May 11, 2010 Franics, It is also possible that your ignition switch may have bought the farm. If so, be sure to get the proper "Break-before-make" contact type of switch, or you will fry the ignition module, in which case it will turn over, but won't get spark. (I know from experience). Also, use caution when "jumping" wires. To be honest, I don't know if it's safe to jump the solenoid or not with this type of ignition, although I'm sure someone who DOES know will weigh in shortly.... Also, I took LOTS of photos during my '88 312 teardown, so if you need any other images, let me know and I'll see if I have what you need. Finally, don't know if the attached info will help or not, but here it is, for whatever it's worth. Share this post Link to post Share on other sites
persof 14 #9 Posted May 11, 2010 Francis: From personal experience, I would check two things, both of which have been mentioned already. First, the PTO safety switch and the under seat switch. I've taped a pad underneath my seat to insure that the seat safety switch gets depressed. Second, check those fuse holders. My 310 won't start until I re-seat and press down on the 15amp fuse, as the fuse holder contacts are loose and corroded. One day I'll get around to replacing it. . . Jeff in Ithaca/Enfield Jeff, I used an ohm meter to check out the seat switch, with the skins removed I can now see the PTO switch and there is corosion in the 20A fuse holder. A trip to the auto parts store is next. Thanks Francis Share this post Link to post Share on other sites
persof 14 #10 Posted May 13, 2010 Where can I get a wiring diagram that shows what the wire colors should be? And if a wire originates here then where does it go to? The "Demistification guide" I had a copy but my computer crashed and it is gone; how can I get another? What pins on the starter solinoid do what? Thanks Francis Share this post Link to post Share on other sites
