wipers not working properly

[scrappyk5]

the wipers on my 1978 gmc truck are not working properly. sometimes they will work , then they wont. when i am saying they dont work, when i first turn them on, whether it be slow speed or fast , they will move about 6" to 12" then stop. and thats it. now if i try later it might do the same thing or it might work. I have tapped on the wiper motor, wiggle the switch, with no change. I am thinking its the motor , what do you guys think?
is there a way to test ?

thanks,
mike

 

[lectric80]

This is most likely worn brushes in the motor. It should be possible to remove the plug at the motor and run power in to get the motor to cycle. I would recommend pulling the wiper arms off while testing, just a protection for damage to the windshield.

 

[scrappyk5]

This is most likely worn brushes in the motor. It should be possible to remove the plug at the motor and run power in to get the motor to cycle. I would recommend pulling the wiper arms off while testing, just a protection for damage to the windshield.

Great idea ! I will run a hot from the battery to the motor itself. i am not
sure which wire would be the hot though. I know the plug is a 4 wire. which color should be the hot?.

 

[lectric80]

I don't have my Blazer here at work with me, so I can't remember off hand. There should be a High speed, Low Speed and Park wires, but I don't remember which is which. It should be possible to get a multi-meter and test which wires have power in the different switch positions, or someone else may jump in with a wiring guide that can tell you for sure.

 

[dhcomp]

not to hijack this thread, but are all the old body style wipers really slow?
My 91 burb wipers are horribly slow compared to my 94. Is this normal?

 

[scrappyk5]

not to hijack this thread, but are all the old body style wipers really slow?
My 91 burb wipers are horribly slow compared to my 94. Is this normal?

My wipers are actually stopping after they move 6-12" and do not work after that till the next day i try them. then they might work or they might not.

To answer your question though, My 1978 when it works is slow on low but work pretty fast on high. Now my 1984, works good in all speeds.

now lets get back to my problem

 

[dremu]

IIRC, the motor is switched on the negative side, i.e. one side is always hot and then the other goes to minus to energize it.

Sounds to me like the motor unit needs to be replaced, and they're not expensive, so I'd just go to your local parts house and get a new (reman) one.

-- A

 

[scrappyk5]

IIRC, the motor is switched on the negative side, i.e. one side is always hot and then the other goes to minus to energize it.

Sounds to me like the motor unit needs to be replaced, and they're not expensive, so I'd just go to your local parts house and get a new (reman) one.

-- A

I can get a reman for about $50, so i will go that route unless someone has one for cheaper

 

[habitatxskate]

i got mine for 30 with a core, it was my first time doing it, and remember to set where it stops or it will bother you until you take the thing apart, for the second time.

 

[scrappyk5]

My wife picked one up for me at the auto parts store on her way home, such a good wife. I will install tomorrow.
thanks all for the info.
i will write back when installed to let you know the outcome.

mike

 

[86dieselburb]

Where you guys finding them so cheap? Checked Vatozone and they want $68 + $30 core.