2003 Chevrolet Avalanche windshield washer

Tiny
AARONIMMUNO
  • MEMBER
  • 2003 CHEVROLET AVALANCHE
  • 5.7L
  • V8
  • 4WD
  • AUTOMATIC
  • 95,000 MILES
The windshield washer pump doesn't appear to be working. When I go to spray the windshield the wipers turn on but there is no fluid coming out. The reservoir is full, I don't hear the pump motor running but I'm not sure if the relay is bad, the wire is bad, pump is bad or if there is a problem with the wiper circuit that prevents the relay from energizing.
Monday, December 15th, 2014 AT 3:52 PM

8 Replies

Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
You're going to have to do some testing to find the problem here. First you have to test to see if power and ground is arriving at the pump. If not you will have to test the inputs to the relay. Two pins are powered by the W/S WASH fuse (15 amp). The switch triggers the relay by applying trigger ground.

https://www.2carpros.com/images/external/104206448.gif
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Monday, December 15th, 2014 AT 4:12 PM
Tiny
AARONIMMUNO
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Thank you, The pump is very difficult to get to and involves removing the wheel well cover. Can we first test all the circuits leading up to the pump? If so, I'm guessing the relay is the first area, do I use an meter testing voltage first? And how? Thank you
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Monday, December 15th, 2014 AT 4:48 PM
Tiny
WRENCHTECH
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What you need is a computer safe (LED) test light that reads both power and ground. In the relay socket you should have power on 2 pins, a reading of continuous ground on the pin that goes to the pump and a switched ground on the other pin that grounds when the switch is turned on.
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+1
Monday, December 15th, 2014 AT 4:54 PM
Tiny
AARONIMMUNO
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Thank you, Can you tell me where I can pick one up? I have a digital multimeter but from your answer that would not work for me. I'm also guessing that I will need to have someone assist me to turn the switch to the washer on while I perform some of the tests. I may be able to tape it to the on position for testing.

Thank you for your help, I'm unemployed at the moment and cannot afford to bring the vehicle in for repair. I do have experience with electronics and auto repair and hope that I can get this repaired.
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Monday, December 15th, 2014 AT 5:09 PM
Tiny
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I don't know what you have available in your area but most any place that specializes in tools should have one.

Here's a couple links to show you what it looks like. The key thing it it will have 2 wires to clip onto both positive and ground to make it work. Some have a cigarette lighter plug too.

http://www.tooltopia.com/equus-3420.aspx
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Monday, December 15th, 2014 AT 5:21 PM
Tiny
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Ok, I found it at Autozone. there is the one you show with both pos and neg connection to the battery and another that just has the ground connection and the probe http://www.autozone.com/test-scan-and-specialty-tools/test-light/innova-transparent-handle-test-light-circuit-tester/186543_0_0/. I'm assuming that I need to get the one you show and connect to ground and positive terminal of battery. Both at autozone say they are for testing the same thing so I don't understand why the one needs both positive and ground connection. Sorry for all the questions, just want to make sure I'm doing this correctly.

Thank you
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Monday, December 15th, 2014 AT 5:42 PM
Tiny
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If it only has one wire, then it's not capable of showing you a ground signal, only power. It needs to be connected to a power source also to be able to read ground.
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Monday, December 15th, 2014 AT 5:48 PM
Tiny
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I see the light you are referring to with only one wire that says it can read ground. It has to have a built in battery or something to be able to do that. I've never seen a single wire tester that can do that.
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Monday, December 15th, 2014 AT 5:52 PM

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