98 FLD120 Wipers

[cowdoc]

My wipers take forever to start. I'm talking like 45 mins.. How can I check to see if it's the motor or the switch??? I use to be able to push the switch in and start them but that won't work now. Elementary I know but I'm an elementary mechanic . Any help will be appreciated.

[Larry227]

Turn the wiper switch on and check for power and ground at the motor. If you have both it's a bad motor. If you don't have power or ground you have a bad switch or an open or short in your wiring or a bad relay.

[cowdoc]

Thanks.

[YerDaddy]

Air or electric?

I just had to disassemble and clean and lube my Sprague HP135. Wipers were getting lazy.

[cowdoc]

Air. 2 lines coming out thru red button (trailer supply) bundle back of firewall.

[Larry227]

So much for my first suggestion. Take a line off at a motor and see if it's getting a good amount of air with the switch in the On position. If it is then you've eliminated the switch.

[YerDaddy]

Not sure why trailer supply would be hooked up to wipers.

Try what I did. Mine works alot smoother and easier.

I had to heat up the nut on the wiper arm to get it off.
Took motor all apart and cleaned every little hole with mineral spirits. Used O-ring lube for re-assembly. Manual says to use Dow Corning 200 (200wt). Vaseline would work in a pinch but will dry up in a year.

I checked my dash control knob too but it was fine.

I hope your air dryer is properly maintained because a contaminated air system will mess up more than your wipers. I hear trucks everyday where their air dryer is spitting every 20 seconds, meaning they have a major air leak and the compressor is cycling 100% of the time. That's messed up.