The rear wiper in my Suburban was going very slow if working at all, tried new wiper motor with no change. It seems to be tied in with rear window defogger, does not work if wiper on.
rear wiper inoperable on 2002 Chevrolet Suburban 1500
I had this same issue a few years ago with my Suburban, The issue stems from an overheating wiring harness plug. The location will be where the wiring harness from the rear gate passes through the upper body roof panel into the flex rubber tubing that goes into the top of the lift gate door. Through this harness and plug assembly passes all the wiring for powering the rear wiper, defrosters, locks etc. The wiper motor running as slow as it does draws quite a bit of current and over time with the connection becoming even a bit corroded the current draw gets even higher which in my case actually caused the plug to melt where the hot and ground wires for the wiper motor melted through the plug housing shorting out and blowing the fuse. When I took it apart it was pretty evident that replacing the skimpy little pin connectors they used for the connection wasn't an option so my fix was the following: First you have to remove the rubber boot that covers the plug which as I said before is on the upper right corner of the door frame for the lift gate. Carefully pull the rubber boot clear of both surfaces (door lift gate frame and lift gate itself. You should also have the trim panel off on the lift gate to make life easier and get more slack. Next check the plug for discoloration and melting. If memory serves its towards one corner of the plug not sure which one. The plug on the vehicle side is anchored to the body of the vehicle via the plastic plug housing. You will have to un-clip this and pull what little slack you can towards you. Be careful not to cut or nick any of the wires on the vehicle side of the plug where it passes over the sharp sheet metal edge of the plug hole. You may have to pry the plug apart if it is melted together as mine was. Once apart visually inspect both sides of the plug male and female. Make sure that no other wire feeds to other accessories such as the defrost or door lock is involved or in danger of shorting out. Remove both the male and female connector from the plug. You will need a small slot screw driver to push the pin tab in on the female side of the plug and allow you to back out the wire connectors. If this doesn't allow easy removal then you will have to get a bit more innovative to remove it. In my case the plug case was so severely melted I had to drill them out using a very small drill bit so as not to drill into adjoining plug connectors. I next used a pair of needle nose pliers to remove the male pins from the male side of the plug. Once I had them out it was clear that I could not reuse either side of these connectors and in my mind they were too flimsy anyway. I took a drill bit the same size as the connector channels that the connector pins are located in and gently and carefully cleared all the melted debris and wire from both the male and female sides of the plug. In doing this you will most likely drill out the little protrusions the connector clip is supposed to catch on when the pins were installed at the factory thus it will not allow you to reconnect these two wires in the way it came from the factory.. This isn't really a big deal and here was my solution. On the back side of each plug cut the pair of wires where there is no remaining signs of melting or charring. By wires of course I mean both the power and ground wires on both sides of the connector plug. Next I used solder connectors rather than crimp connectors. This location is subject to lots of vibration through repeated opening and closing of the lift gate and rattle and shake just traveling down the road...I am a firm believer in an ounce of prevention is worth a ton of headaches later. Before soldering these connectors on I slide a short piece of heat shrink tubing over the wires to slide back up against the connector when I finish soldering it. It makes the installation look cleaner and will prevent corrosion or shorting out of the connectors should the connector itself or where the wire enters the back of the connector touch a bare metal surface. Next we will begin on the lift gate side of the plug. Solder the two male connectors on the lift gate side (un-powered side of the harness). Make sure you put these directly onto the ends of the factory wires on this side of the wire harness. This is especially important if you ever have to unplug these connections again and will save you from having to first remove the rear wiper fuse for work on the lift gate side of things. It is now time to reconnect the male and female sides of the factory plug. I know you are wondering how you will complete the connection:) But wait, you will see there is a method to my madness. Make sure you have enough slack on the vehicle side of the wire harness to allow you to solder two wires on the back side of the vehicle plug.. These wires should be the same gauge or larger and preferably the same color to avoid confusion down the road. If the same color isn't available just be sure to mark which wire is hot and which is ground. You will thank yourself down the road or the next owner of the vehicle will. Slide the heat shrink tubing over the now soldered wires on the vehicle side of the wire harness plug (hot side). I guess I should have said to make sure fuse is pulled before soldering or baring these wires. Use a heat gun to shrink the heat shrink tubing over the soldered wires making sure that the tubing is firmly shrunk down in place with no gaps or burns in the tubing jacket. Next take the free end of one of the wires and route it back through the factory plug extending it past the plug as far as it will go on the lift gate side. Do the same thing with the remaining wire. With the wires hanging take the connected factory plug and reattach it to the body of the door frame (upper right corner) and make sure it is seated in its original position. Now take the free ends of the wires you just passed through the plug and slide a piece of heat shrink tubing over each one and move it away from the area you are about to solder. If the heat shrink gets hot before its in its proper location it will shrink around the wire and you won't be able to use it. Now solder two female connectors that will mate to the male connectors you had previously soldered in place. Once soldering is complete, heat shrink as described before. Once connectors have cooled enough to handle then plug them in hot to hot and ground to ground. Once the connection has been made replace the fuse for the wiper motor (rear) and turn the ignition in the vehicle to on and activate the rear wiper. It should be running as good as factory new again. If not there may be a ground issue on the motor housing. Much hunch though is that this will fix it. Once operation is checked and verified, tape over the connection where the male and female connectors for the wiper power and ground wires are joined. Now slide everything back into the wire harness chase and reconnect the boot on the vehicle body side ot the harness and on the lift gate side. I did this repair on mine 4 years ago and its still working! Helped a friend who had a 2005 with the same problem. It sure beats the unbelievable amount they want for a new wire harness or to have the dealership do it:) Hope this helps
Thank you very much for your response to my question, you were right on, was the problem and fixed it myself. Thanks again and Merry Christmas!!!
Thank you so much for the trouble shooting and fix. Before reading your inputs, I replaced the wiper motor, checked the fuses, checked the switch and was out of ideas for my 2003 suburban. Once I had your information, the wiper was working within an hour.
My rear window wiper motor was making a clicking sound when turned on and would work intermittently. No blown fuse. Using your input, I took the connector apart and put them back together again and everything works fine. Mine was probably just a high resistance connection on the ground wire in the plug. Just unplugging and re-plugging made the contact clean again. If it goes bad again, I may just remove the connector and solder the connections. Thanks for getting me started in the right direction.
It sounds like you may have a high resistance electrical ground for your rear wiper and defogger. They both use the same ground circuit and I would suspect that the wire is damaged where it passes from the door to the body or the electrical connector just inside the body is damaged.
I put my question on this website and within 2 days I received an answer that was right on. Thanks so much, the site is awesome!!!!!!!!!!!!!!!!!!!!!!
My 2002 suburban also has the same problem I checked all wire connector and the door to body connector could not find anything wrong clue less in KC