UTV Wrenching: Chasing Down a Wiring Problem in a Polaris Ranger Crew
One of the most frustrating things to deal with on any ATV or SXS is the thought of a potential wiring problem. I cannot tell you how many times at the start of my mechanical career that I have searched over the harness of a machine to try and figure out where a short might be only to fail miserably in finding it. The entire time I was searching it was actually right in my hands!
During a recent engine overhaul in our Polaris Ranger 800 Crew we noticed some of the telltale signs of the start to future problems. We decided to proceed with the engine removal, yet once it was out, it was then and right then we decided to find and fix these wiring issues. We figured it was better done right away before forgetting what we had discovered.
The wiring in general and combined harness of an off-road vehicle takes an incredible beating as the machine ages. Some wires are subject to chaffing as they come out of the massive wire bundle, but some can actually wear inside the wire sheathing, believe it or not! As was the case on our 2012 Polaris Ranger 800 Crew. The engine would sometimes run erratic at idle, smell very rich from the exhaust (and I am not talking about money rich) and seemed to have minor issues directly linked to fueling including a couple of engine codes. We discovered through a little research that the T-Map sensor on the intake right past the throttle body was a common culprit of similar problems. Although many of these sensors rarely fail it was common for wires to do so.
It was not exactly clear to me at first just which wire was failing us, but with a general direction we had a good starting point anyway. I am very thankful that my grandfather was a thorough man and believed whole heartedly in using an OEM or equivalent service manual for referencing issues that he had not encountered before. Fortunately, I had a Clymer manual specific to Polaris Ranger 800 models and low and behold, in the rear of the book was the most concise wiring diagram. In COLOR! This one investment in this manual saved me hours of searching and I cannot stress enough how valuable it is. If you own an ATV or UTV, a manual like this is a must-have item.
For the life of me I could not figure out how or where the wiring could be broken. As I searched down the wiring route, also displayed in the Clymer Polaris Ranger 800 manual, I figured out that these harness wires are sometimes zip-tied to the side of the intake boot or throttle body in places. I’m assuming this is to keep the wires from falling into the other elements like hot exhaust or rouge trail debris. These were, in my mind, the first spots to check. I cut the zip tie that was holding the T-Map sensor harness and almost immediately I found what felt like a very soft portion of wiring. I also noticed that we might have had a mouse chewing on the wires at some point. The mouse had not gotten the actual wire to break, but inside the sheathing of one of the wires the copper or tinned wire had simply broken in half. It was so hard to believe that this could happen. The wire sheath was soft and pliable, bending very easily to the point that you could see where the wire was missing inside.
So, with this in hand it was time to search out a solution. The wire was actually broken very close to the connector and after getting my hands on some new crimp on spades I was back in business. I simply stripped all of the wires back a little and installed the new spades in place. After installing the original connector, I was back in business.
The rebuilt engine was installed and runs like a champ now with no sign of the previous problems related to the fueling. I did, however, find a problem with the rear control arms and I am off to search out the torque specs in the Clymer manual to see if I have a loose nut or a worn-out bushing there. Oh well. Fix one, find the next!