2018 mxu 500i no electrics at all

[dcman54]

Hello all! This is my first post here. I recently got an mxu 500i with fuel injection and there was no reponse on the electrics. I have gone through all the fuses including the one on the starter solenoid. I have proper 13v going into the atv. I found that I dont have any voltage at the key. Are there any tips for further diagnosis? Also how would I test the ECU to see if its dead?

[CROSSBOLT]

No power at key switch needs investigation. Check battery ground first. Do not worry about ECU just yet.

[dcman54]

Yes I forgot to say that I checked ground and I had ground on the red wire on the key wires. Is there anywhere else that I should check before I start suspecting the ecu? Like a voltage regulator maybe? or does that only regulate what comes off the alternator. Any tips would help! thanks!

[CROSSBOLT]

Yes I forgot to say that I checked ground and I had ground on the red wire on the key wires. Is there anywhere else that I should check before I start suspecting the ecu? Like a voltage regulator maybe? or does that only regulate what comes off the alternator. Any tips would help! thanks!

You are supposed to have 12 volts on the red or black wire at the key switch, not ground! The key switch supplies 12 volts to the systems.

There is a big, fat, black wire between the battery negative post that goes to a ground point on the frame generally. Check that one first. Do NOT even think about either the ECU or regulator/rectifier untill the simple stuff is checked out first.

[CROSSBOLT]

You are supposed to have 12 volts on the red or black wire at the key switch, not ground! The key switch supplies 12 volts to the systems.

There is a big, fat, black wire between the battery negative post that goes to a ground point on the frame generally. Check that one first. Do NOT even think about either the ECU or regulator/rectifier untill the simple stuff is checked out first.

Plus you said you had no voltage at the key!

[dcman54]

I'm so dumb! I ordered a new starter solenoid and nothing changed. I realized that the previous owner wired the starter solenoid backwards. So now I have full power and everything appears to work. I now have a new issue though, the starter motor appears to be too weak to spin the motor over consistently. I've hooked up a jumper on top of a good battery and it can still barely turn it over. I took of the cover on the right side for the manual starting pulley and it is a little tough to spin. Could it just be a bad starter motor or are the more serious issues with internal components? It would be good to know before I order a new starter motor for a 120 bucks. thanks

[CROSSBOLT]

I'm so dumb! I ordered a new starter solenoid and nothing changed. I realized that the previous owner wired the starter solenoid backwards. So now I have full power and everything appears to work. I now have a new issue though, the starter motor appears to be too weak to spin the motor over consistently. I've hooked up a jumper on top of a good battery and it can still barely turn it over. I took of the cover on the right side for the manual starting pulley and it is a little tough to spin. Could it just be a bad starter motor or are the more serious issues with internal components? It would be good to know before I order a new starter motor for a 120 bucks. thanks

Please tell how a starter solenoid can be wired backwards.

[dcman54]

Please tell how a starter solenoid can be wired backwards.

The battery was hooked up to the starter side and the starter side was hooked up to the battery. This way there was no power going to anywhere because the electrics rely on the 30 amp fuse that sits on the starter solenoid. Sorry for the confusion.