Here's a wierd one, My windshield washer pump isnt working at all so I
checked the voltage with a meter at the conector that plugs in the pump and
I get 11-12V when I push the fluid switch. Then I take the pump out and
bench test it with 8-11V from a power supply I have and it works fine. I
checked the connector and Im 100% positive that the leads are making a
connection to the pump but it still doesnt work. I think that some how it is
dropping the voltage when power is suplied and it detects a load, anyone
know why this is happening?
You need to make sure your measuring BOTH wires at the motor plug. If
you have a bad or intermittent ground (on the pumps negative wire) and
were grounding your meters negative lead on the car chassis, you would
get a false reading. I assume your plugs connection are clean and not
You probably have a high resistance connection somewhere in the path of
those two wires. The meter deals with micro amps, so the voltage drop
would not be seen. When the pump is attached, the increased current
across the high resistance connection would result in a voltage that is
too low at the pump.
Try to measure the voltage at the pump with the wires attached. This
can be done by inserting a sewing needle into the insulation of the
wires and attaching the meter to the needles. When the needles are
removed, there will be no exposed wires.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.