Looking for ABS help

[waltmail]

Still sorting through A B S problem. I replaced accumulator and relays. Pump will not turn on at all anymore. Anyone know how to test for pressure switch?

[Ronnie]

Still sorting through A B S problem. I replaced accumulator and relays. Pump will not turn on at all anymore. Anyone know how to test for pressure switch?

I'm assuming you have 12 volts going to the pressure switch.

First unplug the pressure switch and look for brake fluid in the connector. If fluid is there replace the pressure switch. Then unplug the connection to the motor and jump 12 volts directly to the motor. If it runs then the odds are good that the pressure switch is the problem.

[Barney Eaton]

Ronnie has the answer. With a new relay you have eliminated that. (assuming the new one is good). 12V directly to the motor to verify that is is OK then points directly to the pressure switch.

Attached is a photo of the pressure switch for those that don't know what to look for (notice the green tint on the aluminum cover)

Also is shown a cheap plumbing wrench that works for removing them.

Edited May 23, 2010 by Barney Eaton (see edit history)

[waltmail]

Ronnie has the answer. With a new relay you have eliminated that. (assuming the new one is good). 12V directly to the motor to verify that is is OK then points directly to the pressure switch.

Attached is a photo of the pressure switch for those that don't know what to look for (notice the green tint on the aluminum cover)

Also is shown a cheap plumbing wrench that works for removing them.

Where would one source the 12 volts from and where would it be applied on the pump connector. Which pins? Thanks. Got a reference diagram?

[Barney Eaton]

I am pretty sure the pump only has 2 pins. being a DC motor it will run either direction depending on which pin has the 12v applied. For a test I would not worry about polarity.

You can get the 12V from the battery or a battery charger.

[Jim]

Polarity is important as the pump will run backwards if the polarity is not right and will not pump. Before taking the connector off the pump connection note which wire is red and which is black. Hook up your 12V source to the terminals on the pump + to where the red was and - to where the black was.

I am pretty sure the pump only has 2 pins. being a DC motor it will run either direction depending on which pin has the 12v applied. For a test I would not worry about polarity.

You can get the 12V from the battery or a battery charger.

[Guest Richard D]

I am pretty sure the pump only has 2 pins. being a DC motor it will run either direction depending on which pin has the 12v applied. For a test I would not worry about polarity.

You can get the 12V from the battery or a battery charger.

You will need a charger that will put out at least 10 amps to turn over the motor. Some new chargers will not supply voltage unless they detect voltage on the clamps, those would not work for you. Easy way is jumper cables from the battery

[waltmail]

I plan on trying it this weekend. Thank you crew.

[Jim]

I do have good used pumps and good used pressure switches available and can be reached at jfinn@cpinternet.com

[padgett]

I have a little Coleman PMJ8960 10 Amp/Hour Jumpstart System With Work Light that is lightweight & small (important when junqueing) but has enough power for anything I have tried (particularly nice for power seat motors. Is now about four years old and I replaced the plastic clamps but otherwise is still handy.

500 peak amps / 250 cold cranking amps * Reverse polarity indicator light and alarm for added protection * Booster cable ON/OFF switch for added safety * Built-in fluorescent worklight * Dual 12-volt power ports for operating 12-volt accessories