Why do my wipers suck?

[neohic]

This is a problem I’ve had for almost as long as I’ve had my truck. My wipers suck. Doesn’t seem to matter if the switch is on high, low, or anywhere along the delay… they’re slow. Fortunately (when it was actually driven) it never seemed to be in the rain. Now I was fiddling with some interior stuff so I put another wiper module in it out if my pile. Seems to me that I’ve tried putting a few of those in with the same awful result. 
 

Thoughts? Wiring? Wiper motor? Truck in question is an ‘88 Eliminator. 

[Big_Mark]

I've had the same experience and even replaced the wiper motor and those bushings.

I read somewhere that it might be the part of the wiper assembly where you attach the wiper arms to (the spindles?)

So today I pulled out the assembly, and hosed the spindles down with PB Blast, worked the oil in, made sure the new bushings had grease in them, and worked that all in.

When I put it all back in the truck there was improvement.

I wouldn't say vast improvement but I can tell the difference between high and low now so that is somewhat of an improvement over the barley moving at any speed I had previously.

try it!

[eaglescout526]

Have you done the ground improvements? I don't know how I improved mine but mine are pretty good. Not fast by todays standards. 

[JMO413]

I added the ground to mine along with new well greased bushings and they work. I can tell a difference between high and low but that's about all. They do their job but if it's down right pouring your pulling over. I just assumed 30 years ago it was good enough.

[eaglescout526]

I wonder if you were to measure resistance from both ground and power back to the battery, you can start there to start bringing down the resistance and send more power back to the wiper. 

[neohic]

41 minutes ago, eaglescout526 said:

Have you done the ground improvements? I don't know how I improved mine but mine are pretty good. Not fast by todays standards. 

Good point. I don’t recall if I did anything with the grounds in the cab. 
 

On the note of bushings, I put in new about ten years ago… I think.

[youngfred]

18 minutes ago, eaglescout526 said:

I wonder if you were to measure resistance from both ground and power back to the battery, you can start there to start bringing down the resistance and send more power back to the wiper. 

...

 

 

...with the Battery Cables, both-disconnected, of course.

 

 

youngfred

[eaglescout526]

1 hour ago, youngfred said:

...with the Battery Cables, both-disconnected, of course.

Yes of course. Safety first. 

[gogmorgo]

On almost any older vehicle I’ve been in the wipers struggle pretty hard on a dry windshield, but pick up pretty good with a little moisture on the glass. 
Checking for resistance in the wires likely won’t get you anywhere. You’d be looking for voltage drop under load. This would indicate one of two things, either there’s significant resistance somewhere, or else the motor is working real hard to overcome resistance in the linkage.

A brushed motor that doesn’t see much use also runs the risk of corrosion or dust accumulating on the commutator and not working so hot.

[eaglescout526]

Ooo that’s like really diving into the motor right there without going into complete tear down….

[scguy]

1 hour ago, gogmorgo said:

On almost any older vehicle I’ve been in the wipers struggle pretty hard on a dry windshield, but pick up pretty good with a little moisture on the glass. 
Checking for resistance in the wires likely won’t get you anywhere. You’d be looking for voltage drop under load. This would indicate one of two things, either there’s significant resistance somewhere, or else the motor is working real hard to overcome resistance in the linkage.

A brushed motor that doesn’t see much use also runs the risk of corrosion or dust accumulating on the commutator and not working so hot.

Yep, voltage drop is the way to go. 

[cruiser54]

Remember that wipers, turn signals, AC and radio all draw from that weak Brown wire at the ignition switch. 

 

[cruiser54]

I have removed the cover on the wiper motor and removed the dried up waxy grease and then put Moly grease in.

There's also a way to put the later XJ wiper motors in by changing the plug. I've not done that. 

[Minuit]

On 7/30/2022 at 8:22 AM, cruiser54 said:

I have removed the cover on the wiper motor and removed the dried up waxy grease and then put Moly grease in.

There's also a way to put the later XJ wiper motors in by changing the plug. I've not done that. 

I've noticed the wipers on my friend's 2000 XJ are FAR faster than my 91 or 89's ever have been, even after messing with grounds, bushings, and grease.

[cruiser54]

Well, this is right up your alley!! 

[Minuit]

7 hours ago, cruiser54 said:

Well, this is right up your alley!! 

Alright then, guess I'll acquire a 97+ wiper motor and see what happens.

[cruiser54]

I knew you'd take the bait!! LOL. 

[neohic]

2 hours ago, Minuit said:

Alright then, guess I'll acquire a 97+ wiper motor and see what happens.

Please do!