help with wiring short

[white-eagle]

The gremlins have disconnected something again.  We parked our Eagle which is running fine.  2 days later, my wife says buzzing sound.  i check and the air warning buzzer is sounding, and lit up.  also, the "no charge" lite is lit up.  i check and the switch is off, so why would this suddenly start happening with the switch off??  also, i noticed the driver side wiper doesn't move at all, even with air up.  i turned off the disconnect on the main batteries in the back, so it's not really hurting anything.  i just turn the batteries back on, flip the switch and start the engine.  all seems to run ok, but of course, no wiper.  the warning buzzers and light turn off right away when air up.  what do i check first??  i took the dash apart and no wires seem to be loose.

help (again) with some hints, please.

[Nick Badame Refrig/ACC]

Hi Tom,

If you inspected all the fuses and breakers, I would look for bad ground connections next.


It's possible that you have some corrosion.

Good Luck
Nick-

[prevost82]

are your wipers air or electric. ... the wiper could be a separate issue
Ron

[JackConrad]

Tom,
   Sounds like it might be a poor ground connection.  Do you have the wiring schematics for the bus?  Jack
PS: You and Fran need to come down to Ray & Ann's, we will be here until the middle of July.

[Tony LEE]

Can't see that a bad ground can make power available when there shouldn't be any. More likely to be a key switch contact or master relay contact  that is not opening when the key switch is off, or maybe a wire shorting out on a power bus/live stud and allowing  power through to that circuit.

I would have thought that the low oil pressure light would also be on though as they are normally on the same circuit. Maybe not in your rig.

[white-eagle]

the wipers are air operated and i don't see or hear any air leaks.  the right side works fine, just not the left.
jack, you both should have warned me.  i would have made some special effort to get down there to see both of you at the same time with Ray and Anne.  unfortunately, we're only gonna get as close as Cumberland gap on July 9.  no time for a second trip.

no wires loose that i can see on the buzzer.  also, if a breaker was blown, wouldn't it not buzz??  same with bad ground?

[Dallas]

Tom,
I would try recreating the conditions in which this happens then using a voltmeter and a continuity tester follow the connections back to where there is no more voltage on those wires.
The place that was checked just prior to that is the culprit.
Now follow that circuit back to where there is no voltage.
And so on until you find the wire or relay that has undergone a serious smoke release.
That will be your problem spot most likely.
With a caveat....
If it's a relay, it could have a hot wire that shouldn't be and must be followed back to it's source also.

Good Luck!

Dallas

[Sojourner]

i check and the air warning buzzer is sounding, and lit up.  also, the "no charge" lite is lit up.  i check and the switch is off, so why would this suddenly start happening with the switch off??  ......  the warning buzzers and light turn off right away when air up.  what do i check first??  i took the dash apart and no wires seem to be loose.

help (again) with some hints, please.

My concern is why buzzer & gen lite is on after turn off master switch? Could be (if Eagle has them) rear engine control may have by-pass switch???  Does it still repeat problem after each run?
Do have Eagle wiring schematic? Can you attach a photos of schematics from rear engine control panel to front dash?

FWIW

Sojourn for Christ, Jerry

[Sammy]

Sounds like the low air buzzer and gen light are controlled by a relay - it might be defective - stuck
There is probably a low air pressure switch that controls this relay - something else to check?
I have some Eagle schematics for a Model15, I'll try to dig them out tonite.
What kind of Eagle do you have?
Sammy 

[white-eagle]

sammy and others,

let me make sure i explain this right. 
when the air pressure goes down, the low air light comes on and buzzer sounds.  that used to only happen when the air was low, below 70, and the ignition switch was on.  i also noticed that the no charge lite is on and didn't used to be.  of course, the no charge light goes out as soon as i start the engine and charging starts, just like the air buzzer quits buzzing as soon as the air comes up.
if i turn off the main battery switch, then all switches, buzzers, lights go off also.  Mr Conrad had told me to shut off the main switch all the time anyway, just to keep some switch like this air buzzer thing, from killing the batteries.  i never did before because it was too much trouble and what does Conrad know anyways .  Now i know, again, why he told me that.

not all the lights come on.  i notice that the "park brake on" light doesn't come on until i flip the ignition switch on.

the ignition switch has four connectors, 2 white and 2 red.  there is also a remote switch in the back that will stop the engine if its running and has air enough, or let it run.  it will not let the engine start (if there is air) if the front switch is off, but if the front switch is on, then the start button will start it up until i hit the stop button in the back or the fron switch.

just adding that in case that may also be a problem someone has seen.

i should have time to read my own manual (from coach info) and get my voltmeter out on thursday.  any hints as to where to start other than what you all have already provided are welcome also.  i think i've got plenty to get me started on this. aalong with the air wiper that also seems to have quit.

thanks for the help so far.  i'm sure i'll need more and i'll post the fix, if and when i get to one.

[Nick Badame Refrig/ACC]

Hi Tom,

Now I understand much clearer now...

This could be as simple as a faulty ignition switch. Try wiggleing it and see if the problem reappears or disappeares.

Good Luck
Nick-

[NJT 5573]

Build up the air, turn on the wiper motor and start the wiper motor by moving the arm with your hand. It needs to run for several hours and some air brake additive would also help if you can get it into the wiper lines and let it circulate. Mine stick once in a while too, but I always use Rain X if there is a cloud in the sky, then I don't need wipers anyway. Exercise it. I live in Seattle and motors last forever here, probably because they get used alot. Power Service fuel additive is very slippery and I'm going to try some on my sticky wiper guts someday soon. I'll let you know if it makes a difference one way or the other. If the O rings are dead, the motor will usually just lock up.

[white-eagle]

i promised to post our status, so here goes.
as i said, i thought i'd get time today to check and correct stuff.  Grabbed the voltmeter and tool bag and went to the rear to turn batteries on so i could start checking voltage on the switch.  Walked back into the bus.  Hmmm, no buzzer. Nuts, the batteries went dead somehow.  Turned the switch on and all the lights and buzzers came on.  Not the batteries.  i wiggled wires, pushed buttons, moved levers, but i could not get anything to malfunction.  Well, as long as i already have the dashboard open, let me work on the wipers and get them going.  Turned the knob and the wipers started!!!

I'm now even more of a believer.  This Eagle knew i wanted to go somewhere and tomorrow is Friday.  It just wanted some attention in between trips.  Obviously, she is a lady and TLC works.  Maybe i'll rename it "The Magic Bus" and paint stars on the sides.

Or did one of you swing by and fix all this stuff last nite??  Next time, please show me what you did or direct my efforts.

Since none of the problems seems to be a critical issue, i'm going to wait for it to crop up again, i guess.

[DrivingMissLazy]

Tom, I did not find it unusual for my wipers to not start sometimes. Especially if they had not been run for a period of time. Occasionally I had to go outside and push it to get it started. After that it would be OK.
Richard

[Len Silva]

Betcha a buck that these gremlins come back and it will ultimately turn out to be a bad ground somewhere.  They can be a bear to find but sooner or later will become less intermittant and easier to track down.

The problem with the wipers is completely unrelated to the electricals.

Good luck,

Len