Washer motor and ghost 12v

[Lolo256]

Hi everybody nice to meet you, 
I have a new washer pump (old one died) that works perfectly when directly connected to my bikes 12.4v batterie system (testing purpose), but when i connect it to the dedicated connector of the car it dont works (this one give 12.4v when i push the washer command as it is expected ). I checked polarities from the beggining and the motor fonction (rechecked on bikes). 

Note that i try the motor on the exact same condition for both tests (water not plugged to the car system but hanged on top of a "test bath").

How this could be???could not be amp related fpr me because the bike batterie is a lot smaller...

Thanks a lot for your help!

Edited by Lolo256 on Thursday 14th June 22:19

Edited by Lolo256 on Thursday 14th June 22:19

[Belle427]

The connectors at the pump end have probably corroded internally, you may be getting a voltage drop under load because of this.
It will appear fine when tested with a multimeter but not work as soon as a load is connected.

[Lolo256]

 Thx for the answer...i removed the connectors without any results....
I also tryed with a 12v led and a tester both are not functionning...i still have a 12.46 volt that dont power anything... 

i tried to put the negative directly to my battery and keep the positive plugged on the connector and nothing happen, at the opposite when i keep the negative pluged on the connector and i put the positive on the battery the pump will function... i presume i dont have a bad negative but the positive is problematic...

Do you have an idea to sort it out?? This car cant have wires change do you have an idea for a Ir or bluetouth remote system then i could power it up from the drivers seat ....

Thanks again!

[N7GTX]

Follow the positive back from the motor. You have proved the earth is good so look for a poor connection. If you cannot find a bad/corroded join then it may well be the switch itself.
As said above, you can easily have 12.5v on a multimeter which takes no load, but once the motor tries to turn it takes a load. If the wire was damaged and only one strand was making a join you would get 12.5v but the motor would not turn as the single strand will not carry the required current.

[Steve_D]

With the ignition on do the wipers give a couple of sweeps when you select 'Wash'? This would indicate there is something happening with the switch but still does not confirm it is passing plenty of current.
You could try applying +12v to Pin W at the wiper switch this is the Blue/Yellow wire. Or Pin 53c (also marked 41) at relay 9 on the fusebox.

Steve

[Lolo256]

thank for the last two answers that was very helpfull!!! Yes i just miss the fact that icould have some voltage but if there is no current that can make his way it will be problematic!! i found out that the wires where totally burned or corroded or both and where black... I just putted a new switch onboard and manually actionnate the washer fluid (only for technical inspection to tell the true).

Thx for your help!