Hi, I have a 2013 Ram 1500 sport. Last week, the wipers stopped working on my way to work. I unfortunately assumed that it was the motor and just went ahead and picked up a motor from the wreckers and changed it. They still didn't work. I then talked to a my mechanic and he said that it was probably a switch issue. I used a test light on the 4 pin plug and with the switch off, the center 2 pins will light up but the outer 2 do not. I turned the switch to all three positions (intermittent, low and high) and only one of the center pins lights up. I changed out the switch and nothing changed. I am assuming that there is a ground wire issue. Problem is, I have no idea which wire is the ground wire. One wire looks brown or black with a red stripe and the other wire is brown. (these are the outer 2 wires) center wires are black with white stripe and a black wire. Can anyone tell me which is the ground?

I also changed out the 30amp F25 fuse...I believe that this is the only fuse there is...let me know if I am wrong.

 

You're correct, fuse 25 is the only fuse for the wiper motor directly. It provides power through the Wiper On/Off Relay and the Wiper High/Low Relay, then to the wiper motor. Terminal A of the wiper motor (Brown/Orange tracer) wire is the High Speed feed wire. Terminal B is the Low Speed feed (Brown/White tracer), terminal C (Black) is the ground, and Terminal D (Brown/Gray tracer) is the wiper park wire.

The Body Control Module controls the relays and gets the signal via the CAN Bus as to what mode is selected and when the wipers should swipe as well as when the washer pump should pump. If you happen to have access to a professional grade scan tool or AlfaOBD, you should be able to use the tool to tell the BCM to activate the wipers and/or washers. That would help determine if you need to be looking in the direction of the switch or in the direction of the BCM/relays/pump. But if you don't have access to such a tool, then using a test light or multimeter you can still make some voltage checks to see what's going on. For example, providing power and ground at the wiper motor to terminals B and C respectively would tell you if the low speed wiper motor function works. If the wiper motor works, then you can use the meter or test light to confirm your ground to connector terminal C is good. Assuming it is, then you could move to testing the relays and wires between the relays and the wiper motor. That's a bit more involved and will require a bit more time to type up than I have time for at the moment.

If you confirm the pump is okay using the steps above, reply back and I can type up how to check out the relays and wiring between the relays and the pump. Or if I get some time through the day I'll try to write it up as well.

-Rod

 

Several of the following checks can be made with either a multimeter or test light. Checking for continuity is a bit more challenging with a test light, so I’ll type this up as if you have access to a multimeter. If you do not, you’ll need to get creative with using the test light, or possibly skip some of the continuity measurements and just make the voltage measurements. That most likely will work fine, until you get to a point where you don’t have voltage, then you may need to confirm continuity.

Using the multimeter or test light, confirm you have power to and through fuse 25 (30A). This circuit should be hot at all times, so no need to have the key in the Run position. If so, pull the “Wiper On/Off Relay” (WOOR), the “Wiper High/Low Relay” (WHLR), and unplug the wiper motor. With these relays removed, use you multimeter to check for continuity between relay socket terminal 86 for both sockets to ground. You should have good continuity for both of these to ground. Also confirm continuity from the WOOR socket terminal 87a to ground.

While still set to measure continuity, confirm continuity from the WOOR socket terminal 30 to WHLR socket terminal 30. If that all checks out good, now check for continuity from the WHLR socket terminal 87a to wiper motor connector terminal B (Brown/White tracer). Also confirm continuity from WHLR socket terminal 87 to wiper motor connector terminal A (Brown/Orange tracer). These should both have continuity.

If this all checked out so far, the next step will be to perform some voltage checks and the test the relays. For all of these measurements I’m going to assume your wiring does not have corroded connections. If everything checks out in the steps listed, then you may have a corroded connection somewhere and you’ll want to repeat many of the steps using a test light to load the circuits. Switch your multimeter to measure DC voltage and check for battery voltage at WOOR socket terminal 87. This is the power feed from Fuse 25. If that voltage is good, next turn the key to the Run position and turn the wipers on to Low speed. Now check for voltage as the WOOR socket terminal 85. If you have voltage here, next measure for voltage to WHLR socket terminal 85. At this point you should NOT have battery voltage. If that’s correct, next switch the wipers to High speed. Now you should have voltage to WHLR socket terminal 85, and still have power at WOOR socket terminal 85. Turn the wiper switch back to the Off position. If you don’t get battery voltage to either of the relay socket terminals 85, that would point to an issue with the Body Control Module, CAN Bus, or switch.

If that’s all good so we, we can next use the WOOR and WHLR sockets to test the relays one at a time. Pick one of the relays and install it in the WOOR socket. With the wipers still off, confirm you have a good ground reading at WHLR socket terminal 30. If so, next turn the wiper switch to the Low speed setting and now you should have battery voltage at WHLR socket terminal 30. If so, that relay under test is good. Swap it with the other relay and repeat the same checks to confirm the other relay is good.

The last thing to do would be to test the wiring from the relays to the wiper motor. Since above you checked continuity from the relay sockets to the motor connector, this shouldn’t really be necessary, but this will be easy to check with a test light in case you don’t have a multimeter. If both relays are not already reinstalled, install them now. With the ground lead of your test light or meter grounded, switch the wiper speed to Low. You should measure battery voltage at terminal B (Brown/White tracer). Next, switch the wiper speed to High and you should have battery voltage on terminal A (Brown/Orange tracer). I’m not real confident on the Wiper Park voltages of terminal D (Brown/Gray). I suspect that when the wipers are Off this will measure ground, and when the wipers are On this will measure battery voltage, but the vehicle wiring diagram doesn’t make that terribly clear. It would seem to agree with you getting the test light to light when the wipers were turned on at the switch though.

Good luck, and report back please with what you discover!

-Rod

 

Sorry it has taken so long for me to update this thread. It turned out that I needed to change the TIPM. Hard to believe that with all of the fuses and relays in it, it only takes 1 small cell to go bad and you have to replace the whole darn thing. Thankfully I was able to pick one up from the auto wreckers for $225. Thank you again for all of your help.

 

I'm glad you found the issue. $225 for a used part seems high, but I'm sure that's well under what a new one would cost, if you could even find one.

-Rod

 

Rod,

To me that is a lot for a used one too but just a reminder, that is $225 Canadian dollars not US dollars haha. I was quoted $795 Canadian for a new one.