Abs brakes

[Zephod]

My bus has a 5A ABS fuse (which, oddly, seems to connect to the horn button). That fuse has a problem in that before I replaced the blown fuse, I had no current drain. Now I have a constant drain.

That drain could be either in the ABS system, about which I know nothing. All I know is I have electric assist hydraulic brakes. No electric wiring goes to the rear wheels. Or the drain could be in the horn system, about which I know nothing. Somebody has re wired the horn to a switch on the dashboard rather than via the horn button (which when pressed seems to fire a solenoid or relay).

I have an international 3800 from 1994. Has anybody any ideas?


Sent from my iPad using Tapatalk

[Geoff]

The electric brake booster should be hooked up to the key switch so it only works with the key in the "on/run" position.  The horn should be hooked up to a permanent "on" hot connection.  The clicking is the horn relay switch.  I am guessing the horn isn't working.  So trace the wires.

--Geoff

[Zephod]

I'm hoping the culprit is going to be in the horn wiring and is going to be easy to trace.

Somebody wired in badly an external speed sensor that doesn't work and I'm going to have to find out why it's there. Already removed most of the dangling wires. I have a gps speedometer right now. Mind, governed to 55 on the flat, I don't have too much to worry about!

Now I've completed the living quarters, I'm working on the bus systems that need work. Totally different thought process!


Sent from my iPad using Tapatalk

[Jim Eh.]

The electric brake booster should be hooked up to the key switch so it only works with the key in the "on/run" position.  The horn should be hooked up to a permanent "on" hot connection.  The clicking is the horn relay switch.  I am guessing the horn isn't working.  So trace the wires.

--Geoff

Actually this is not quite correct. The electric brake booster should NOT be connected to a keyed power source. It should have constant power and be controlled by a self resetting breaker NOT a fuse. And it should be run on a 25+ amp breaker certainly not a 5 amp.

Given that it is possible for someone, lets say unknown reason, were to turn off the ignition thinking it throttle is stuck and turning the key off will save them, they would no longer have any power assist for their brake system.

It is possible the electric motor could be the cause of your current drain. There should be a pressure switch connection in the master cylinder area. You could try disconnecting that for a day or two to see if you batteries go dead.

If that does not show anything try disconnecting the horn circuit at the horn(s) and do the same test.

[Geoff]

I guess the people with hydraulic and vacuum brake boosters​ are SOL.

--Geoff

[Jim Eh.]

How so?