Washer Electrics Driving me Nutts!!

[Pacman1972]

Assumed my washer motor was duff until I took it out and put 12V's over it to find it works perfectly

So using a volt meter I measured the wires connected to the washer motor and sure enough when I pull the washer switch/stalk I get a "-12v" reading. So why oh why is it not #@#!ing working

So here's where I'm a bit confused.
1. it's reading "minus" 12v (Pretty sure the leads are the right way around)
2. I have continuity between the live (Yellow/Blue) and engine/earth.

Obviously something wired wrong, but really not sure where to look next! Anyone?

[taylormj4]

As already said, probably poor contact between the connectors - they're right down there at the front of the car aren't they (pump integral to washer bottle?).
Clean or replace.
If you're connections were the wrong way around, the motor may run anyway but backwards (depends what type of motor it is).
Another check is to plug the positive feed onto the pump motor as normal but leave the negative feed off. Then connect your voltmeter between the negative wire and the negative terminal of the pump. When you activate the washers, you should see 12V appear on your meter. Then reverse the setup so that the voltmeter is between the positive feed and the positive pump terminal (negative feed replaced onto pump). This proves that the connectors are making contact and that the circuit through the pump is healthy.
Cheers, Matt

[TJC46]

Once you have sorted the electrics out also check the non return valve is fitted the right way around. Its a tiny inline item usually close to the pump.

[PRTVR]

when you say its working do you mean it is making a noise ?
mine was doing the same thing and all I did was use a elastic band on the washer stalk to the steering wheel to keep it running and tapped the pump with a screw driver handle and it started working, it might just have dried out, make sure the water container is topped up before you start.

Phil

[Pacman1972]

Thanks for the tips all

The bit that threw me is the continuity between the live and the earth. i.e. if I take the wire reading 12v (yellow/blue) and then have the meter check the continuity with the engine case I get a connection whereas the other wire with a zero reading (black) has no continuity with the engine case. I'm no electrician as you've probably guessed but logically this seems wrong to me.

I'll try out your suggestions this week and report back.

Cheers

[taylormj4]

Pacman1972 said:

Thanks for the tips all

The bit that threw me is the continuity between the live and the earth. i.e. if I take the wire reading 12v (yellow/blue) and then have the meter check the continuity with the engine case I get a connection whereas the other wire with a zero reading (black) has no continuity with the engine case. I'm no electrician as you've probably guessed but logically this seems wrong to me.

I'll try out your suggestions this week and report back.

Cheers

When you say "continuity" do you mean you are using an ohmmeter or a multimeter on ohms setting ? You need to be careful with either of these as they can cause a short. A voltmeter, or multimeter set to volts is the safest way to test things as it has a high internal impedance and will not cause shorts.
If you were using an ohmmeter, then yes, there should be low resistance between the black lead and an earth point (e.g. engine case). Note that dependent upon design, the washer switch may be in the negative side of the circuit, so you should make sure the switch is ON during testing.
Cheers, Matt