Electric over hydraulic brakes

[dan t.]

I have a HydraStar hba 12 electric over hydraulic brake actuator on my Roadrunner trailer.
All was working good then just quit, it still works on
the break away circuit (yellow wire)
I ran all the tests in the service manual, then disconected it and ran the tests directly off a fully
charged battery,no change.
It acts like there is no power to the black wire which is not the case
If anyone has any ideas I sure would like some feedback
Thanks, Dan

 

[bruceb58]

You apply power to the yellow wire and it works? What if you manually apply 12v to the blue wire which is normally driven by your brake controller? BYW...that is one of the tests.

 

[dan t.]

You apply power to the yellow wire and it works? What if you manually apply 12v to the blue wire which is normally driven by your brake controller? BYW...that is one of the tests.

Still nothing, the test is white to negative blue and black to positive, it should run and pump, all I get is a click.

 

[dingbat]

Given what you say to this point…your brake controller is suspect

 

[dan t.]

Yes definetly an internal problem, I was hoping someone had experiance fixing these things. $2800 here in Canada.
I will be taking it to the shop where I work and strip it down, see if I can find the problem. Then there is finding parts, that could be a planned event.

 

[dingbat]

Still nothing, the test is white to negative blue and black to positive, it should run and pump, all I get is a click.

This makes no sense.

If the diagram up above is correct.....

Black is power (+12 VDC)
White is ground (-)
Yellow is alternative power (+12 VDC)
Blue (Control Voltage) - variable....X to 12 VDC depending on gain setting of controller

What happen if you put +12 VDC on the blue wire?

Set brake controller gain to 50% and test for voltage between white and blue wire

 

[dan t.]

Well I found the problem, i took off the cover where the wires enter, this uncovers the motor, the relief solinoid and a circuit board, nasty greenies all over the circuit board.
I checked with all the local dealers, total waste of time, called Roadrunner ,the circuit boards have been on back order for 6 months
Bought a complete new unit $1600+freight+tax , yikes.
Problem is solved
Thanks for the replys
Dan

 

[bruceb58]

Well I found the problem, i took off the cover where the wires enter, this uncovers the motor, the relief solinoid and a circuit board, nasty greenies all over the circuit board.
I checked with all the local dealers, total waste of time, called Roadrunner ,the circuit boards have been on back order for 6 months
Bought a complete new unit $1600+freight+tax , yikes.
Problem is solved
Thanks for the replys
Dan

When I used to store my trailer outside, I put a plastic bag over the EOH unit throughout the rainy season. It was open at the bottom so it could breathe but kept the rain from hitting it.