Wiper Motor Testing

[BFH 429]

Currently in process of installing wiper assembly to my project.  I was considering using the old wiper motor, but have no idea of condition, etc.  I figured that since it was always meant to work in the elements, these units should not really degrade over time, etc.  Does anyone know if these units are problematic or how to test them to see if they are on their way out the door? 

Marc

 

[cwalker509]

Do you plan to drive very often in the rain? I plan to check basic function on mine hopefully today. I have 2 that I pulled from cars in the 90s. I know one was working when pulled. I plan to just directly jumper to a battery. If it turns on then I am good to go but i do not plan to drive I n the rain but I could get caught off guard at some point. They ground thru the case I believe. I had to jumper from the wiper case to a bolt on the 72 Mex to get reliable operation on it. It uses a completely different motor and want to keep it as original as possible (see pic before jumper installed))

 

[Stanglover]

Marc, this might not help too much, but NPD list wiper motors (rebuilt and repops) for the 1970. Maybe check with them and Summit etc. if you feel you need a replacement, do some web surfing. Mine is 50 years old, single action, and still works fine........ or as fine as it can be on a Mach 1.

 

[BFH 429]

@ C Walker - Yeah, the plan with this car is to takeout on trips - hence the 6 speed.  I'll definitely avoid the rain, but I know I'll get caught in it at some point, so this system has to work.  I'd like to use an original piece if it's still ok.  Maybe I can call one of these remanufactures to see what they recommend for a test.  Do you have a wiring diagram for these motors?  I think they have four wires.  

Also, do all Mustangs use 2 speed wiper motors?

Marc

 

[BFH 429]

Hey Geoff...yeah, I priced out some replacements, If this unit seems questionable, I'll definitely go that route.  

Marc

 

[Bentworker]

There isn't much to them.

One common thing that gets gummed up is the cam / pushrod assembly inside that makes it so the wipers park in the lowered position.  If it isn't working properly the wipers will stop wherever you turn off the switch.  A little disassembly, cleaning and fresh grease works wonders.  As for how to test them I found it easiest to test it by plugging it into the car harness.

 

[BFH 429]

Bentworker - this is a good pointer, we'll be sure to take a look.  Do you know what kind of grease is needed for the insides of the case? 

 

[BFH 429]

Also to allow this thread...I took a look at the Ford shop manual, and it does tell how to actually test the motor for proper operation (current draws etc.).  I was a bit surprised about this...I didn't think the manual would get down in the weeds like that.  

 

[cwalker509]

Rockauto offers them sometimes (Cardone rebuilt i think). Not terribly affordable. I have one to use and one as a spare. They are pretty straightforward.  There are 3 brushes (mine were fine) and a couple of bearings (also looked fine).  Not much else to go wrong unless something breaks.  Motor is supposed to be grounded thru one of the attachment bolts and they often end up with bad grounding.  Break out an ohmmeter and check for resistance from motor body to a known good ground on car.  Is your motor seriously rusty?  Look at the wiki here on this website to decipher the wires (I tried but not familiar with what each of the 4 wires represents....looks like two of them are involved as a switch of some sort)

 

[Bentworker]

I don’t know for sure on the grease.  Probably something pretty thin like NLGI  0 or 1.  You don’t want something too thick that will gum up the “park” mechanism.

 

[giantpune]

Not to completely hijack the thread, but I have a similar situation.  I have a new wiper switch in my dash.  Turning it n does nothing.  The wiper motor was replaced in the car years ago, but has never worked.

Suspecting maybe the wiring that's to blame.  The wires at the wiper motor are the easiest to get to.  Does anybody know which ones to measure across to test for voltage when the wiper switch is turned on?

 

[Don C]

The shop manual volume 3, section 35-60 has the troubleshooting for the switch.

When the switch is in the Off position there should be power on the red wire, in Low there should be power on the red wire and white wire, in High there should be power on the red wire and the dark blue/orange stripe wire. The reason power is always on the red wire is because it is used to 'park' the motor and wiper arms.