I have a 2006 Polaris Sportsman 800. I was throwing a code 42 initially and ended up replacing the cooling fan (it was junk), the thermistor on the side of the block, the wiring harness going into the thermistor, both relays under the ECU, and the 20A circuit breaker in the "black plastic bag," which I found on the left side of the ECU if you are facing the front of the 800 looking toward the back. Everything checked out fine, including the fan running continuous if I unplugged the harness to the thermistor.

However, after a couple of rides code 42 presented itself once again, and the fan does not work at all, even if I unplug the wiring harness to the thermistor.

The only thing at this point that I have not changed out is the thermostat.

Seems to be an electrical issue. I've spent weeks on this reading forums and trying different things to no avail.

Any help you can give is greatly appreciated.


B. rgds, Kelly

 

If you unpluged the temp sensor on the side of the head and the fan doesn't come on then the problem could still be a wiring short or short in the fuse block wiring itself since you replaced both relays,one being the fan relay and the 20 amp circuit breaker.

 

Thank you. Can you pls tell me if the 20A Circuit Breaker near the ECU is the only Circuit Breaker for the fan? I've noticed some people say there are CB's near the head lamps or attached to the frame. Guessing those are for other models.

 

Only one cb to the fan relay. A lot of people had problems with those and also the fuse block that allowed water in and pins would corrode causing intermittent contact.Might be another good place to check along with the wiring for shorts. Delphi fuse blocks are available or some have just made individual sealed breakers in place of the block.

 

I checked the fuse block and the connection to the fan did not work. I took it apart, stripped wires, reseated, etc., and now have power to the socket when I test it with a light, however, as with the 20 amp for the lights right next to it, I don't get a reading when checking the fuse itself, only when I check the socket with a light (lights work though, when I pull the fuse, they turn off; when I plugged it back in, they come back on).


Also, checked the 20A Circuit Breaker, I have power to both sides of it.


Then checked the connection that plugs into the wiring harness that came with the new fan. I have no power there.


When I get home from work tonight I'll try to follow those wires through the harness, as well as check the connections that I put in/on when I installed a new harness at the Thermistor a few weeks back.......maybe I'll get lucky and something worked loose as I used crimp connections supplied and did not solder. If I take it apart, I will solder all connections.


Thanks for all of the help/input.

 

Sounds like you're narrowing it down. Sensor yellow and purple wires lead to the ecu,from there to the fan relay where the orange/black wire is powered up and sends voltage to the fan. Hopefully might be as simple as a faulty ground (brown) wire. keep us posted.

 

I ordered a new fuse block with connectors from Quad Logic in MN (www.quad-logic.com) on Tuesday afternoon of this week - it arrived yesterday/Thursday, two days later. Quad Logic PN 100-3010. Cost $22.95 + $8 in shipping. Very good quality, extremely happy with purchase. Only place I could find it - all other suppliers would only sell the complete wiring harness with fuse block. Ordered additional parts from a different supplier on Tuesday as well, offered to pay expedited shipping. I still don't have a tracking number. Will likely be sometime next week.


Quad Logic - A+

 

Hope that was the problem. Keep us updated.

 

I put the new fuse block in and it checks out fine. I also followed the brown wire (as well as orange with black stripe) and from what I can tell, the brown wire(s) go back to the frame near the battery. I ran down and bought new ends, soldered the wires, and put it back together. The fan is still not working. I checked the wires going into the connection that the fan plugs into and I don't think there's power. As well, I don't have power to the purple and yellow wire from ECU to Thermistor. I spent 10 hours trying to figure it out today. I'm at a complete loss. Not sure what else is left to try and I really don't want to take it to the dealer (surrender in defeat).


Any help is greatly appreciated.

 

Almost forgot, as well as consistently getting a code 42, I am now getting a code "3.4" when I put the unit in test mode (turn key on 3 times within 5 seconds and leave it on without starting).


Thank you, Kelly