troubleshooting windshield washer pump

[heftylefty58]

I bought a used 2003 Yukon w/ 50k miles on it, and just realized that the front washer pump doesn't work--it doesn't even make any noise when I try to trigger it. (The wipers work fine, and the rear washer pump/wipers work fine, too.)

I'm not terribly experienced with working on cars, but I figured I could at least check the easiest thing first: The fuse box.

According to the owners manual, the fuses for the pump relay and the pump are located at the underhood fuse block. I confirmed that the actual fuse for the pump is fine.

However, I'm not familiar with the fuse for the pump relay. It's much bigger than any fuse I've seen before, and I'm hesitant to yank it out because it looks like it is locked in there pretty good. Is there a tool I should use for pulling this sucker out, or is it not meant to be pulled off the block? In the diagram, this particular fuse has the numbers 86, 30, 87, and 65 on each corner. Any idea what these numbers mean?

Any other troubleshooting tips you can offer before I just buy a new washer pump and try to replace it myself?

Thanks in advance!

 

[Rollin Thunder]

i think its one pump for both, enless im getting that confused with one fluid tank, but its common for the pipes to come off and your just spraying it all over and not where its supposed to go. the pump is really quiet (atleast on mine) so it may be hard to hear it, if it is infact working. My 2 cents. :thumbsup:

 

[JKmotorsports]

In the diagram, this particular fuse has the numbers 86, 30, 87, and 65 on each corner. Any idea what these numbers mean?

Any other troubleshooting tips you can offer before I just buy a new washer pump and try to replace it myself?

Thanks in advance!

Sounds like what you are referring to is the relay itself. The numbers are the contacts on the relay, 86 and 85 being the contacts to energize the coil and 30 and 87 for the high current contacts. You just pull it straight out to remove.
If you have a meter, you can test to see if the pump is getting voltage while activating the pump. If you have voltage at the pump, then the pump is suspect. If not, then you could have a bad relay, fuse, switch, or wiring issue.

 

[GTO2050]

Check to see if the holes are plugged. Use the end of a paper clip. If the rear works, it is pulling from the same reservoir so you know that is okay. There is a different pump for the windshield but you should be able to hear it with some sort of stethoscope device (handle end of a screwdriver?)

 

[slamkeys]

Definitely Two Pumps Down There

I just replaced both of my pumps due to a leaking battery that corroded the pump housings and tubing. Both of the pumps are basically the same, but you have to specifiy front or rear when you buy a new one because the connector sockets are different (this ensures that when you turn on the front wiper you don't squirt the rear window. :smilielol:

I had a heck of a time finding any information on this when I was troubleshooting mine, and neither of my shop manuals even had any pictures of the pumps.

Incidentally, I bought mine at the dealer to the tune of about 40 bucks each, but you can get generic equivalents at the auto parts stores for less than 20 bucks.

One common problem with these pumps is that the retaining pin on the top of the pump gets brittle and breaks off, so be careful when snapping a new one into place - the pins have grooves in them that allow them to flex inward when you push them into the retaining notch, but the grooves also make them fairly weak.

 

[heftylefty58]

Thanks all!

At this point, I have another set of lamebrain questions since this will be my first time dealing with automobile electronics in my profoundly non-eventful life:

I want to perform a test where someone hits the washer switch while I check for power at the connector. Instead of using a $2 test light (since I don't have one), I want to use my multimeter at the connector.

Assuming my multimeter looks like the attached drawing, where should I set the dial? Also, what value(s) should I hope for in the reading when the switch is on vs off?

I'm embarrassed to admit that I don't even know if I should be testing for voltage, current, or resistance. However, if this is any consolation, I do know this much:

• Volts = Current * Resistance
• Power = Volts * Amps
• My read multimeter lead must be plugged into different holes depending on
  whether I want to test for current, voltage, or resistance. The black lead always goes into the COM hole.

That pretty much sums up the extent of my electrical knowledge...despite almost 2 decades of schooling.

Any advice is greatly appreciated--thanks in advance!

P.S. Just thought of another question: Is it safe to test the pump by connecting jumper wires directly from the pump to the battery? If so, how exactly should I connect the wires?

 

[JKmotorsports]

You'll be testing for voltage, so your DMM dial should be set exactly like the picture shows, at 20 on the DC setting. You'll want roughly around 12-14 volts with the washer switch pressed, depending on if engine is running or not.
And yes, you can directly test the pump by sending +12 volts to the red wire on the pump harness. Try that out and let us know how you're doing.

 

[heftylefty58]

Sorry fellas--I didn't see your responses until after I worked on the car and then called it a day.

Here's what I did, as well as my findings:

1) Tested the pump connector's voltage while the wife triggered the pump. Result: Zero volts.

2) Tested the pump's voltage at the fuse box while the wife triggered the pump. Result: Zero volts.

3) Tested the radio's voltage at the fuse box. Result: ~12 V. (Dammit!)

I was hoping that my multimeter wasn't working properly, or that I was misinterpreting the results. So, I proceeded with the following tasks:

4) Removed battery.

5) Siphoned out washer fluid tank; then uninstalled it.

6) Bought new replacement pump from local auto parts store; then replaced the pump.

7) Put everything back together. Result: The pump still don't pump. (Dammit!) The wiper blades still work, so at least I didn't worsen the situation.

Apparently, steps 4-7 were a waste of time and money.

Based on my results from steps 1-3, what would you say the problem could be, and what should I do from here? Should I replace the connector? Do I have to visually inspect the entire wire circuit between the battery and the connector? If so, how do I do this considering everything's so friggin crowded in there?

Thanks again for your help.

P.S. Tomorrow, I'll try the test where I use a jumper wire to connect the positive terminal of the battery to the red wire on the pump harness. I'm a little skeptical that I'll be able to pull this off considering what I said above: Everything's so friggin crowded in there. Do you have any tips? (I have a some leftover 14-2 romex cable laying around in the garage that I plan to use as a jumper wire.)

 

[Getwired]

Sounds like it could be that the control stalk (multi-switch) is at fault...

 

[brodg]

check the 15amp w\s washer fuse in underhood fuse box should be hot at all times. swap the w\s wash relay in underhood fuse box with another relay from box like horn see if that works if not you are going to have to pull the cowl to get to the wiper motor module and check voltage on the pink wire at the module while activating the switch if you have power there then you have a faulty wiper motor module if no power then you have a faulty switch.

 

[heftylefty58]

check the 15amp w\s washer fuse in underhood fuse box should be hot at all times. swap the w\s wash relay in underhood fuse box with another relay from box like horn see if that works if not you are going to have to pull the cowl to get to the wiper motor module and check voltage on the pink wire at the module while activating the switch if you have power there then you have a faulty wiper motor module if no power then you have a faulty switch.

Thanks for the suggestions.
I checked the 15amp w\s washer fuse in underhood fuse box: no voltage.
I swapped the w\s wash relay in underhood fuse box with the horn relay: Washer still didn't pump (but wiper blades still worked).
I confirmed the horn did work with it's own relay.
Yesterday, I already confirmed that there was no voltage at the pump connector while activating the switch.
Could my switch be faulty even if it successfully triggers the wiper blades?

 

[brodg]

if you have no voltage at the 15 amp w\s washer fuse then that is your problem it should have voltage at all times. i will look at a shematic and get back to you.

 

[brodg]

ok looked at the schematic if you have no voltage on the 15amp fuse you have an open in the underhood fuse box. a simple test would be to jump another hot fuse to the dead 15amp fuse and see if the washers work.

 

[heftylefty58]

***Please delete this particular post. (My question in this post is now irrelevant because I found out that "w/s washer" exclusively refers to the FRONT washer.... It does NOT include the REAR washer.)***

 

[brodg]

take a jumper wire from the positive cable stud on the underhood fuse box and use a safety pin and touch it to the top of the dead 15amp fuse have someone try the washers if it works the bus bar in the fusebox is faulty or you have an open connection under the box.

 

[heftylefty58]

take a jumper wire from the positive cable stud on the underhood fuse box and use a safety pin and touch it to the top of the dead 15amp fuse have someone try the washers if it works the bus bar in the fusebox is faulty or you have an open connection under the box.

Thanks brodg. Believe it or not, I have a set of questions for this:

1) Does it matter which side of the dead fuse I touch with the safety pin?
2) If so, do I risk damaging anything if I touch the wrong side first? And how do I figure out which side is the correct side?
3) Instead of taking a jumper wire from the positive cable stud on the underhood fuse box, can I just connect directly from the positive terminal of the battery?

 

[brodg]

it doesn't matter what side of the fuse you jump to. and yes you can come from the battery voltage is voltage.

 

[heftylefty58]

I just bought a GM service manual (as well as a test lamp), and I can't believe I attempted to troubleshoot my problem without it. It's shocking to see how grossly I oversimplified things--the schematics and other diagrams are very helpful.

The manual instructs to perform this test:

Test the resistance from the windshield wiper switch supply voltage circuit terminal to the windshield wiper switch signal circuit terminal in the windshield wiper motor harness connector.

Does anyone have any tips on how to do this?

Do I need to buy special long-a$$ multimeter leads so that I can stick one of lead somewhere on the turn signal lever (where the wiper switch is), and the other multimeter lead on the windshield wiper motor (which is at the bottom of the windshield)?

Also, has anyone removed/installed the windshield wiper motor? Seems like a pain in the buttocks--do I really need a battery terminal puller to remove the wiper arm from the drive shaft? Were you able to separate the wiper motor from the transmission assembly without buying these special tools:
-J 39232 Wiper Transmission Separator
-J 39529 Wiper Transmission Installer

If I have to buy those tools for this job, I'm wondering if it'd be more cost-effective to simply have my local mechanic (or the dealership) try to fix the problem.

What do you guys think?

 

[heftylefty58]

I've attached a screenshot of the bottom portion of my underhood fuse box. You can see that the W/S WASH relay is just to the left of the W/S WASH fuse. Couple more questions regarding 2 more tests I need to perform....

Connect a test lamp test from each of the windshield washer relay battery positive voltage supply circuit terminals in the underhood fuse block to ground.

As you know, there are 4 terminals for the washer relay. How can I tell which 2 terminals are supposed to have the positive voltages?

Connect a test lamp from battery positive voltage to the windshield washer relay control circuit terminal in the underhood fuse block.

...and how can I tell which 2 are supposed to be the control terminals?

 

[heftylefty58]

Quick update for anyone who's patient enough to follow along....

I can finally can narrow down where the problem lies: I jumped my 30/87 terminals in the washer relay, and the washer activated!

So, according to the manual, it looks like the problem lies somewhere at the turn signal lever (ie, windshield washer switch) or the windshield wiper motor module. Hopefully, the problem is the wiper motor circuit board, as that is only a ~$30 part.