2011 RMX450z Require some assistance locating possible wiring/connector issue?

If your HS400ATV is not powering up even with a fully charged battery and you've already replaced the ignition switch, there may indeed be another module or component that could be causing the issue. Here are a few possibilities to consider:
1. Main Fuse: Check the main fuse for the ATV. It is typically located near the battery or within the fuse box. Ensure that the fuse is not blown and is making proper contact. A blown main fuse can prevent power from reaching the ignition switch and other electrical components.
2. Starter Solenoid: The starter solenoid is responsible for engaging the starter motor when you turn the ignition key. If the solenoid is faulty or not functioning correctly, it can prevent the ATV from powering up. Inspect the solenoid for any signs of damage or loose connections. Consider testing the solenoid or replacing it if necessary.
3. Kill Switch/Safety Interlock: Check if there is a kill switch or safety interlock feature on your ATV. These safety mechanisms are designed to prevent the ATV from starting under certain conditions, such as when the brakes are not engaged or if the ATV is not in neutral. Make sure these switches are in the correct position and functioning properly.
4. Wiring and Connectors: Inspect the wiring harness and connectors for any loose, damaged, or corroded connections. Pay close attention to the connections between the battery, ignition switch, and any other modules or components. Clean and tighten any loose connections, and repair or replace any damaged wiring or connectors.
5. Electronic Control Module (ECM): The ECM or other control modules could be a potential source of the issue. These modules control various electrical functions in the ATV. However, diagnosing and testing these modules often requires specialized tools and knowledge. It may be best to consult a professional ATV mechanic or an authorized dealer who can properly diagnose and test the modules if needed.
If you've checked these possibilities and the issue still persists, it is recommended to seek professional assistance. They will have the expertise and equipment necessary to diagnose and resolve electrical issues specific to your HS400ATV.

Did you replace belt?Is it tight enough?Do you have fusible links?Check alternator wiring,may need replacing.Check battery,old alternator could of made it bad.Check ground battery cable,follow it's other end that is screwed into block.Also check positive cable to starter.Did you have the old alternator tested?Unlikely new alternator is bad.

Voltage Regulator Bleed Test if the battery is discharging wile sitting unused.

Ensure that the regulator is connected to battery, then unplug voltage regulator connector at the engine crankcase (the stator connector) to isolate the regulator from the stator windings. THEN using a test light, touch one probe to a suitable ground and touch the other to the regulator pins, one at a time. IF the tester light glows at any time the regulator is defective (shorted) and needs to be replaced.

OTHERWISE:

Motorcycle voltage regulator connections must be clean and tight for proper operation so it must be verified that both the AC (stator) connections and the DC (battery supply side) connectors are clean, fully inserted and locked in place with the regulator latches (they should also be coated with dielectric grease to keep them clean and corrosion free).

The motorcycle voltage regulator is a series regulator that is also a rectifier that changes stator supplied alternating current (AC) to direct current (DC) which the battery system requires. If the charging system does not keep the battery properly charged both with regards to Voltage (between 13 VDC minimum and 15.5 VDC maximum) and the current supply at a high enough amperage to meet the system lighting, ignition, TSM/TSSM, security and accessory requirements plus a minimum of 3.5 more amps (3.5 amps more than the foregoing system requirements) there are a number of tests that can be done to ascertain why.

As the voltage regulator must have a good, clean, tight (and otherwise secure) ground connection for proper operation a Voltage Regulator Ground Circuit Test can be accomplished by connecting an ohmmeter to a known good ground (like the battery negative post) and the case of the regulator. If there is continuity with little resistance the ground is GOOD and nothing more needs to be done BUT if there is NO continuity or there is more than minimal resistance the ground will need to be fixed so there is a low resistance continuity by either locating and fixing the poor ground or adding a new grounding wire from the regulator case to a know good ground.

A Voltage Regulator Power Circuit Test can be accomplished by turning OFF the Ignition, disconnecting the voltage regulator and with an ohmmeter set to the Rx1 setting, testing for continuity between the voltage regulator wire harness supply terminal and the main fuse terminal (with the fuse removed) and if there is continuity present then the wiring circuit here is GOOD but if there is NO continuity then you will need to either find the open and repair it or replace the whole wire running from the voltage regulator to the main fuse.

As there should be no short circuit in the power supply from the regulator to battery (main fuse) wiring OR in the regulator internal circuitry continuity from these both need to be checked again with an ohmmeter set to the Rx1 setting. If the regulator to main fuse wiring connector is not disconnected from the regulator you can connect an ohmmeter with one lead on the regulator supply wire terminal end at the main fuse (with the main fuse removed) and the other lead to a known good ground. If there is NO continuity then you know that both the supply wire and the regulator are okay (as there is no short to ground). BUT if there is continuity then either the regulator or wiring or both is/are shorted to ground. To determine where there is a short circuit (i.e. either the wiring or the regulator internal circuitry) you must disconnect the DC side of the wiring harness (the connector at the DC side of the regulator) from the regulator and test between either or both ends of the wire i.e. from the regulator wire harness connector terminal and a known good ground and/or the main fuse terminal end of the wire and a known good ground. If there is any continuity the wire is shorted to ground and the short circuit must be found and repaired or the wire must be completely replaced. If there is no such continuity then the regulator DC supply terminal (with the DC side of the regulator connector disconnected) must be tested by putting one lead of an ohmmeter on the regulator terminal and the other on a known good ground. If there is continuity the regulator is shorted to ground and must be replaced. If there is a short in the wiring it is unlikely BUT the regulator could ALSO be internally shorted so it should also be checked either before or after any wiring short is located and repaired.

The voltage regulator must also properly regulate the rectified DC voltage supplied to the battery so that it is not less than 13 VDC or more than 15.5 VDC. If the regulator is not properly limiting supply voltage to the battery to 15.5 VDC or less it will be overcharging the battery. This can be tested for by operating the motorcycle engine at 3000 rpm while placing a voltmeter between the battery positive and negative posts and reading the supplied voltage. If the reading is greater than 15.5 VDC the regulator is defective and must be replaced. If the voltage is less than 15.5 VDC but more than 13 VDC the regulator and the rest of the charging system are operating correctly. If the supplied voltage is less than 13 VDC the AC side of the system must be tested and if the AC side is good but the supplied voltage at the battery is less than 13 VDC then the regulator is defective and must be replaced. If the AC side of the system is not providing correct AC supply then the stator must be tested and if it is bad, replaced and if it is good then the rotor inspected (cannot be electrically tested as it consists of permanent magnets but it could be inspected fro physical damage and roughly tested for strong magnetic force fields by using a ferrous metal object to see if the attraction of the magnets is strong or weak, but this is basically a better guess rather than a precise measurement). The rotor can also be physically inspected for physical signs of damage including signs of the center hole having become oval AND the stator bolts inspected for possibly having come loose and into contact with the rotor.

Have you tested the wiring between the two fans? Back probe the fan that's not working, whats the voltage reading at the fan connector? If 12V check for a lose or broken wire between the connector and the fan. If no voltage the wiring between the fan connector and the fan has an open circuit. Also don't overlook the possibility of a bad ground for that fan.

The early GM products would build up restance in the wire that went from the alternator to the starter. The easy cure for this is to install a 10 guage wire directly from the Alternator Batt. lug directly to the battery postive post. Do this using the correct end connectors.. do not just wrap the wire around the termanel. This was a big problem on these cars. especially the Diesel cars. Always disconnect the battery ground terminal before you work on this.

If the car stops running, it sounds like a faulty device in the main 12v feed from the battery to the main fuse block (including ignition), which is abnormally going open under usual loads. This could be a fusible link, fuse, relay or circuit breaker - you will need a wiring diagram or service manual to figure out which might be the culprit (try Alldata.diy.com).

see the diagram attached.God bless you

A short blows fuses - you have a situation where the voltage is either not reaching your bulbs or possibly a bad ground.

See if you get a hold a schematic for car so you can trace out the power and locate the anomaly.