Rotsun85 Posted June 3, 2017 Report Share Posted June 3, 2017 Soooo, I just bought my 3rd 720 all 85 2wd and this one is a wiring disaster! Alt is testing good on bench but only putting out 11.3 on the truck? Battery is new and good. Is there a chance these have a on/off from ign. To alt.? If so what do I need to check for? Thanks Quote Link to comment
datzenmike Posted June 3, 2017 Report Share Posted June 3, 2017 11.3 is not any charge and probably reading the battery... which should be more like 12.6 Turn ignition to ON (don't start) does the red charge light come on. Is the plastic plug securely plugged into the back of the alternator? Quote Link to comment
Rotsun85 Posted June 3, 2017 Author Report Share Posted June 3, 2017 11.3 is not any charge and probably reading the battery... which should be more like 12.6 Turn ignition to ON (don't start) does the red charge light come on. Is the plastic plug securely plugged into the back of the alternator? Yes and yes Quote Link to comment
datzenmike Posted June 3, 2017 Report Share Posted June 3, 2017 Check the Black fusible link. Make a temporary jumper. If burnt/melted charge cannot get back to the battery. Quote Link to comment
Rotsun85 Posted June 3, 2017 Author Report Share Posted June 3, 2017 Check the Black fusible link. Make a temporary jumper. If burnt/melted charge cannot get back to the battery. Where is this link? Quote Link to comment
datzenmike Posted June 3, 2017 Report Share Posted June 3, 2017 The 2 green and 1 black fusible links are connected to the positive battery post and are not far from it. Something like this... Quote Link to comment
Rotsun85 Posted June 3, 2017 Author Report Share Posted June 3, 2017 And shouldn't I still be getting higher than 11.3 at the alt itself? Quote Link to comment
datzenmike Posted June 3, 2017 Report Share Posted June 3, 2017 Your battery (if fully charged) should be about 12.6... it may be discharged somewhat. When engine running and alternator charging it should be above 14 volts. Quote Link to comment
Rotsun85 Posted June 3, 2017 Author Report Share Posted June 3, 2017 Your battery (if fully charged) should be about 12.6... it may be discharged somewhat. When engine running and alternator charging it should be above 14 volts. Ok I've traced down the wire through the links and up to a mess of wires from previous owner. The there were maybe 3 wire strands holding onto the crimp connection to the battery cable. I checked voltage and getting like 300v from the wire that needs to go to the battery! That cant be right? Quote Link to comment
datzenmike Posted June 3, 2017 Report Share Posted June 3, 2017 Check your device you are using for measuring the voltage. Should be on voltage and under 20 volts. Quote Link to comment
Rotsun85 Posted June 3, 2017 Author Report Share Posted June 3, 2017 I made my own connection straight to the battery. My charging light is now not on but still no charge? Quote Link to comment
Rotsun85 Posted June 3, 2017 Author Report Share Posted June 3, 2017 Choke shut off and now light is back on... What the heck is happening lol Quote Link to comment
Rotsun85 Posted June 3, 2017 Author Report Share Posted June 3, 2017 Ok I've found that it doesn't charge until the choke shuts off. When it does its charging great I can unhook the battery and all now but as soon as it starts charging the light come on Quote Link to comment
datzenmike Posted June 3, 2017 Report Share Posted June 3, 2017 The wiring is fucked up. The choke doesn't shut off. It warms up and opens. It has an electric heater that warms it and keeps it warm as long as it's running. Power is supplied through a relay that needs a charging alternator to work properly. I would avoid running with the battery disconnected from the the cables. I asked if the red charge lamp is on with the ignition on, not started, and you said yes. Now you say it comes on when charging, so what happened? When charging the red charge lamp should be off. Quote Link to comment
Rotsun85 Posted June 3, 2017 Author Report Share Posted June 3, 2017 The wiring is fucked up. The choke doesn't shut off. It warms up and opens. It has an electric heater that warms it and keeps it warm as long as it's running. Power is supplied through a relay that needs a charging alternator to work properly. I would avoid running with the battery disconnected from the the cables. I asked if the red charge lamp is on with the ignition on, not started, and you said yes. Now you say it comes on when charging, so what happened? When charging the red charge lamp should be off. It used to stay on. I rewired from after the fuse link straight back to battery opposed from the birds nest it was. Now its off when not running and when you start it it stays off until idle down from choke opening then it comes on and starts charging... I don't fuckin know man but at least it is charging now lol. Quote Link to comment
datzenmike Posted June 3, 2017 Report Share Posted June 3, 2017 Red light should be off with the key off. On when in the ON position. This is to show the driver that the bulb works and isn't burned out. Off once started and the alternator charging. Might flicker slightly red when idling at low RPMs. The red lamp should be connected to the battery on one side and the alternator plug (white wire) on the other. When charging, there is 12 volts on both sides and the bulb can't light. If not charging, battery flows through the lamp to the alternator diode to ground and lights Quote Link to comment
Rotsun85 Posted June 3, 2017 Author Report Share Posted June 3, 2017 Red light should be off with the key off. On when in the ON position. This is to show the driver that the bulb works and isn't burned out. Off once started and the alternator charging. Might flicker slightly red when idling at low RPMs. The red lamp should be connected to the battery on one side and the alternator plug (white wire) on the other. When charging, there is 12 volts on both sides and the bulb can't light. If not charging, battery flows through the lamp to the alternator diode to ground and lights I get that, I just don't understand why it's doing the opposite in mine. I tested it again after drive and I'm getting 13.8 at alternator and 12.7 at bat seems like some resistance going on as well. Quote Link to comment
datzenmike Posted June 3, 2017 Report Share Posted June 3, 2017 Clean the battery clamps. Should have same voltage anywhere in the charging system. 13.8 would be enough to push a charge into a 12 volt battery. Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.