1987 Silverado Wipers Slow

[bcbbabtexas]

87 Silverado with some slow wipers and windows. I can put the wipers in any speed and they stay slow. Wiggled wires..nothing. I tried grounding the case, no improvement. Any ideas?

 

[89Suburban]

What's your volt meter read?

 

[bcbbabtexas]

slow wipers

I noticed there are two plugs that plug into the motor. I checked voltage on one of them and it was 12.25 ish

 

[89Suburban]

Yeah but what is the voltage when the load is applied and the wipers are running?

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[chengny]

More details will help. For example:

Have the wipers and doors always been slow?
Did they get slow at the same time?
How slow are the windows - how many seconds from full down to full up?
When you say the wipers are always slow, do you mean they only operate in the slow speed mode - but not in high speed? Or do you mean that they move slower than if they were at the normal slow speed.
If you do have a volt meter, does it go up considerably if you rev the engine?
How is your heat/AC fan - does it seem to run at full speed? Or is it slow too?
Did one day, the wipers just go slow when you turned them on - and they have never worked right since?
Did they gradually keep getting slower and slower?

As 89Sub asks, what does your dash volt meter read (if you have one)?
If you do have a volt meter, does it go up considerably if you rev the engine?
I think what he was trying to determine is whether you have a system wide electrical problem or just a wiper issue.

 

[bcbbabtexas]

slow wipers

More details will help. For example:

Have the wipers and doors always been slow?
Did they get slow at the same time?
How slow are the windows - how many seconds from full down to full up?
When you say the wipers are always slow, do you mean they only operate in the slow speed mode - but not in high speed? Or do you mean that they move slower than if they were at the normal slow speed.
If you do have a volt meter, does it go up considerably if you rev the engine?
How is your heat/AC fan - does it seem to run at full speed? Or is it slow too?
Did one day, the wipers just go slow when you turned them on - and they have never worked right since?
Did they gradually keep getting slower and slower?

As 89Sub asks, what does your dash volt meter read (if you have one)?
If you do have a volt meter, does it go up considerably if you rev the engine?
I think what he was trying to determine is whether you have a system wide electrical problem or just a wiper issue.

Thank you for the help but.. As far as the post from sub89, the wipers run slow when in "lo" and run the same speed when in "hi". I don't see that on the diagnostics. I do own a shop manual (the fat one) and it wasn't much help either. As far as Chengny's questions:

Have the wipers and doors always been slow? I just got the truck. It's been this way since I bought it a month ago.

When you say the wipers are always slow, do you mean they only operate in the slow speed mode - but not in high speed? Or do you mean that they move slower than if they were at the normal slow speed.

Slow both.

If you do have a volt meter, does it go up considerably if you rev the engine?
How is your heat/AC fan - does it seem to run at full speed? Seems ok, the blower stays on all the time when ignition is on.

Did one day, the wipers just go slow when you turned them on - and they have never worked right since? Since I bought truck, they have done this.



Did they gradually keep getting slower and slower? No

The power windows are also slow.

 

[bcbbabtexas]

As far as reading the voltage when the wiper motor is running, where do I need to read it? Rookie HERE! Also, I see some of the diagnostics referring to control module, I assume that is the rectangle device under the steering wheel? By the way, I just put this motor in from Advanced auto.. and there is no ground strap. Are the bolts/grommets the ground?

 

[chengny]

The grounding is through the bolt in the upper RH corner.

But that isn't the main motor ground.

The motor is continuoulsy supplied with power at terminal 19. The grounding leg is fed through the switch on the column and makes contact with the frame/body at the main ground bus (under the dash over by the parking brake).

Here is a simple little diagram that shows how the wiper motor is wired:

 

[bcbbabtexas]

Yes thats correct. You can put it in lo or hi and its always SLOW!

 

[chengny]

Yes thats correct. You can put it in lo or hi and its always SLOW!

Sorry, I deleted that question. Seemed a bit sarcastic.

So, your wipers are so slow.... that they are not even able to maintain normal low speed - correct?

And a new motor is installed - correct?

I know it's a pain in the ssa but you really should disco the motor from the wiper arm linkage and see if it runs at normal speed. If so, look closely at the linkage for binding problems..

If that does not get the motor speed up to normal, I think you are looking at a new wiper switch. It's not expensive, but that R & R can be a pain - it's inside the steering column.


Before anything else; are you absolutely POSITIVE that your overall electrical system voltage is running at the normal voltage of about 13?

And why does your heater fan run whenever the key is turned on - is that regardless of swtch position?

BTW; these power windows do not exactly shoot up - IIRC even under the best circumstances, full stroke from down to up takes almost 5 seconds.

 

[89Suburban]

As far as reading the voltage when the wiper motor is running, where do I need to read it? Rookie HERE! Also, I see some of the diagnostics referring to control module, I assume that is the rectangle device under the steering wheel? By the way, I just put this motor in from Advanced auto.. and there is no ground strap. Are the bolts/grommets the ground?

The wiper motor does not traditionally ground through the housing. The ground wire of the wiper motor is part of the harness and is controlled and grounded though the module, which is the rectangular device under your steering column. If that is a new motor and it only works on one speed follow the troubleshooting chart. I find the wiper switch itself wears out more often than the module.


Sorry about that Jerry we were posting the same time LOL

 

[bcbbabtexas]

The chart didnt show my scenario. How would I go about removing the switch? Take off steering wheel then it comes out of column?

 

[ScottyB]

This may be a stupid thought but what kind of fuses are used on an 87? If they are glass fuses could you have a loose fuse? Tight enough to carry voltage but not tight enough to carry the amperage. Just a thought and I may be way off base.

 

[89Suburban]

The chart didnt show my scenario. How would I go about removing the switch? Take off steering wheel then it comes out of column?

The whole turn signal switch pulls out of a socket. You have to have everything turned to the off position and give it a good yank and it will pop out. The wire on it feeds through the column and is a real bitch to feed through it. The connector for it is in the same area as the module. White connector. When I put my new one in I just ran the wire outside the column and phuckit. New switches on eBay are 25 bucks shipped.

 

[89Suburban]

This may be a stupid thought but what kind of fuses are used on an 87? If they are glass fuses could you have a loose fuse? Tight enough to carry voltage but not tight enough to carry the amperage. Just a thought and I may be way off base.

They are blade fuses