This happened a year ago too. When it is cold the wipers malfunction. I put the switch to intermittent, slow or fast and the wiper does not work and then it will move a bit. The only mode it works on is the manusl mode where you pull the swich toward you.


I would think it was the switch, but they work fine when it is warm out.

 

It is a bad switch.
When it gets cold the contacts shrink, when they are worn out they shrink to the point of not making contact anymore, if you crank the heater in the truck and get it nice and warm inside the cabin the wipers will work normal.
You need a new wiper switch, keep a eye on the forum, as winter approaches you will see lots of DII owners posting this same question

 

Heres a drawing to look at. The "flick wipe" function bypasses everything and always puts volts to the high speed side of the motor. If motor does not work in any other position, switch is certainly prime suspect. You could confirm this by parking with window cracked, to be sure inside temp is low as possible. Turn on key, don't crank, and run wipers. If they don't run (as you expect if cold) - use hair dryer to warm up the switch area and retest. Maybe connector on switch needs to be re-seated, but probably need the switch like Spike says.

 

Another odd wiper issue - my wipers only work on low or high - the delay and "flick wipe" function do not work. would this be the switch or the delay fuse?

 

Power for the wiper motor come from fuse 19 inside the truck, and goes to high, lo, and flick wipe. If flick wipe does not work, but high and low do, would indicate switch.

The variable delay adjust drives the BCU, which commands the wiper relay in the fuse box. Might be that relay,

So I would vote for switch.

 

anyone know how to disable the rear wiper when you are backing up in reverse "feature"? short of a hammer?

 

Controlled by BCU, not much chance. Same signal probably makes reverse lights get switched on. Drawing attached.

 

Turn the wipers off.

That is a safety feature so I dont know why you would want to disable it, I wish my truck had it.

 

How hard is it to replace I hope I don't have to remove the steering wheel

 

I am afraid that the RAVE indicates otherwise. See attached. You will also be moving the mobilization coil, and having to worry about air bag deployment. READ the Rave procedures indicated. Whe working around air bags usually good idea to disconnect battery.

Now all of that said, I have seen posts on other sites for other vehicle models about people taking the switch apart and cleaning the metal bands inside, etc. Don't know if squirting in some contact cleaner (rag below to catch spray and drips) would buy you anything. If problem is a build up of oily dirt from donut eating Alaskan previous owner, who knows?