Same thing I always did. Copper post coming from battery,silver leading to what was being protected. Same as the main circuit breaker on non efi model. Copper post facing battery. Not that it probably makes any difference which way you hook one up.

 

So here's what I've figured out/done early this morning:


1) Replaced both new NAPA Relays with new Polaris OEM Relays (no difference)
2) Fan Relay - Orange/black wire from relay to fan still has no power; two connected Red/white wires have power; Red wire has power; Yellow/black wire from ECU to Relay has power
3) Second Relay - Red/black wire has no power (same slot on second relay as orange/black on first relay); Red/white wire has power; Orange wire has power; Gray/white wire has power.


Essentially the Black/Orange wire on fan relay (to fan itself), and the Red/Black wire on second relay (again, both in same position/slots but on separate relays) have no power. All other three wires or sets of wires going into the Relay have power.


Is it possible the ECU itself is bad by not closing the loop? Is it possible the ignition is not sending power or signal to ECU for fan?


Still showing a code 3.4 when first turning key on, then a code 42 once running.


Thanks, Kelly

 

If I do need to order a new ECU, the 800 Sportsman was manufactured 08/07/2006 but is a 2007 model year (VIN 4XAMH76A07A939180).


The ECU itself was made by Bosch in the U.S. (Date: 07/28/06). The PN & SN are partially worn off (PN F00HM0..... / Polaris PN: 40116..... / SN 108303).


Not sure if I would need to order a 2006 or 2007 ECU if it comes down to it (guessing 2006)?


Also, am assuming ECU comes pre-programmed (plug-n-play)?


Thanks, Kelly

 

That's kinda of what I'm thinking as the manual shows the ecu sends signal to relay to close that powers up the Black/Orange wire. Plus ecu provides the ground path. Ground path from the ecu to fan may be the problem.

 

Can you please tell me if the new ECU (ordering from Partzilla today) will be pre-configured (plug-and-play)? I'm guessing so, just want to make sure.


I'll let you know once I receive it and get it back together, likely by the end of this weekend.


As always, thanks much.

 

I know we had to reprogram ecus if we took a new one or transferred one from another vehicle for tests.Ecu is set up for your machine and has to receive the input from the sensors in order to adjust fuel, idle,etc to your particular engine.

 

I ordered a new ECU from Partzilla yesterday.......also ordered a new ignition switch w/ keys (needed, old one worn out). I contacted Partzilla ahead of time and gave them the VIN # and info off of existing Bosch ECU, they provided the part number (4011599), which is for a 2007 Sportsman 800, even though the unit had an ECU manufactured in July of 2006.


Partzilla had to order parts, which I'm completely o.k. with, so I probably won't have until mid-next week. I will let you know how everything goes. Again, appreciate all the feedback and advice. Kelly

 

Part # you quoted is the same listed on several sites. Hopefully it will crank up. If it doesn't it will need to be programmed/flashed to your machine.

 

I received the new ECU last night and installed it with the battery disconnected. Afterwards, I hooked the battery up and ran the diagnostics (turn key 3 times within 5 seconds). Here's what I came up with (am guessing I need to have the unit taken to dealer and ECU flashed as mentioned by Old Polaris Tech):

- Code 3.4 as I turned key on initially
- Code 42 while running diagnostics
- Then code 25 while running diagnostics
- Code 42 after diagnostics complete

When I turn the key on with the new ECU installed, the fuel pump does not initiate, nor does the unit turnover, whatsoever. However, I do have power at the fuses, relays, etc.

If I reinstall the old ECU, I get the same codes, less the 25, but the fuel pump initializes and the unit turns over and starts.

I'm not sure if it's related or not, but the unit has always had the rear red lights (I replaced the work lights switch and they work fine) come on as soon as they key is turned, and prior to starting engine.

I do have a new ignition with keys coming tomorrow/Thurs but, again, am assuming at this point the new ECU needs flashed.

Any help you can give is greatly appreciated. Thanks, Kelly

 

Needs to be placed on Digital Wrench and set up for your atv.