2002 S60 2.4T AWD No washer MVSolved, bad ground

Post by **kdaide** » 22 Jul 2014, 20:56

Hello Volvo Experts:

I need your assistance with a strange problem that has me perplexed.

One day, out of the blue, my windshield washer stopped spraying washer fluid. There is no sound coming from the pump so I figured the pump was gone. I checked all fuses before hand.

I took the bumper off and located the washer pump. I checked for power at the wiring harness and recorded 11V when calling for washer fluid. The headlamp wipers activate at the same time and operate normally. but nothing from the pump. This would make you think that my suspicion of the pump failing was correct; however, but when I manually power the pump from a fresh 9V battery, the pump works find.

Why can I make the pump work with a 9V battery but when I attach the wiring harness which is delivering 11v the pump does not work. I am out of ideas and I really need this fixed!

Could it be that the wiring harness is not delivering enough current? How would I check for this?

Any suggestions for further things to test is GREATLY APPRECIATED.

Kind regards.

Kevin
2002 S60 AWD, 2.4T, 304,000kms

Post by **precopster** » 23 Jul 2014, 00:42

Some electrical systems work this way: they hold both terminals at the supply voltage then drop one of them down to ground to create a potential difference.

Are you certain that you weren't measuring just one of the terminals while having your black lead of the multimeter on chassis ground?

To put it simply were both leads at the wiring harness when you were switching the squirters on?

Post by **abscate** » 23 Jul 2014, 05:12

Poor connections are the usual cause of electrical problems. My guess is you are getting voltage to the connector, but it isn't passing through to the motor. Take a good look for corrosion on the motor electrical connections

draser · Post by **draser** » 23 Jul 2014, 05:32

Like Mike's suggesting, if you measure voltage at connector between connector and chassis you'll see the 12v on one pin. But you may have an open ground wire. Try measuring with both leads at connector. The other issue is a bad switch-even though you see the 12v when you flip the switch it makes poor contact and can not carry the current required by pump.

mf70 · Post by **mf70** » 23 Jul 2014, 06:31

Corrosion at any junction in the system can raise the resistance. The motor needs high current: the VOM does not. If you could check the voltage with the pump in the circuit, I'll bet it doesn't get to 11V.
Check connections.

Post by **kdaide** » 23 Jul 2014, 07:15

All - Thanks for the help. Below is some more information and a question

1. the contact points look clean. I actually bought a new washer pump because they're cheap so I know its contacts are good. The wiring harness is a little harder to inspect because it's the female end so I can't see inside of the contacts but from the outside, they look clean. how do I clean the inside of these contacts?

2. When I measure the voltage I did so across the two contacts on the wiring harness and my voltmeter showed 11V. I did not measure from one side to the chassis.

3. I was able to get the motor to spin using a 9V battery so i'd think 11V should work as well. Not sure about the current levels. I'm not sure how to measure amps in a DC system.

Not sure what VOM is? (Voltmeter maybe?) MF70. How do I check the voltage with the pump in the circuit? Where do I put my voltmeter leads?

I really appreciate the help. Please keep it coming.

Post by **regent** » 23 Jul 2014, 07:27

VOM=Volt Ohm Meter

When you read the 11 V across contacts, was the pump attached or not?
I suggest that you use some small gage pins attached to the meter probes to read at the connector from the back while the pump is attached so the circuit will be complete (hopefully). I bet you will read next to zero which will indicate loss of ground. There is a harness behind the bumper that may have been pinched.

Post by **kdaide** » 23 Jul 2014, 07:52

Regent: Thanks for the response.

I read the 11V across wiring harness while it was disconnected from the motor. To do this, I simply stuck the ends of the Red and Black probe into the female end on the wiring harness.

Are you suggesting the I try and read the voltage from the other harness that is attached to the bottom of the washer bottle. This harness feeds both the washer level sensor and the pump? I tried to disconnect this harness but could not figure out how to get it apart. Since I don't have a hoist, it's hard to get under the car to get a good look at the connector to see how it comes apart.

Post by **regent** » 23 Jul 2014, 08:01

Whatever way you can measure with the washer pump connected in the circuit will work. Without the pump you had battery voltage, and with it connected you will read no voltage across its pins to prove you have a ground fault.

But I suggest you find a pair of jack stands or ramps first because you will still need to inspect some wiring under there and repair the issue.
It could be as simple as a poor ground terminal to chassis but it may be a broken wire as well.

Check this out for the '02S60 schematics: http://www.volvowiringdiagrams.com/volv ... agrams.pdf
The Windshield Washer Pump circuitry is on page 60.
The possible suspect wiring problem is somewhere from (and inclusive of) the grounding point 31/1 (see page # 171 for location) to the gounding pin 4 in the connector to the washer pump.
Cheers!

Post by **kdaide** » 24 Jul 2014, 07:16

All -

PROBLEM SOLVED. I so appreciate everyone who gives of their time and expertise to helped me fix this problem and learn a little more about my car along the way.

The issue was with the ground wire, it was broken down below the washer bottle. A quick splice and everything is back in order.

With much appreciation, Kevin