lights seem to be shorting - diagnosis?

[monahowell]

Hi everyone -- I've got an 86 Carpenter (yeah, I know -- hopefully not rolling over any time soon). Anyway, my problem is that all of a sudden the headlights have decided to operate sporadically -- the high beams are fine, but the low beams go off without rhyme or reason. Even weirder, the low beams somewhat consistently blink off when the brakes are applied. What on earth could create such a collaboration? My husband finally resorted to driving with the high beams on but what a bummer for the oncoming traffic!

Does anyone have any idea where I should look first to track down the problem? I am a complete newbie and have no clue on most things electrical -- but I catch on pretty fast, if you can explain with plenty of detail.

Bought our bus August 7th, 2006 to take a single trip and resell -- now we love it so much, we can't give it up. Just WAY too much fun!!

Thanks so much for being here!!

Mona

[wtd]

I'd take a look at the dimmer relay, I'd think that everything else in the headlight system, hot connection, bulb grounds, switch connections, etc. would be common to both high and low beams and any problem would affect both high and low lights.

[monahowell]

Thanks so much -- I'll try to check into the dimmer relay. Is that the button on the floor that you stomp on to change from high to low beams?

I really wish I knew more about all this. I am learning, slowly but surely, but not fast enough for my taste.

Anyway, I'll climb around down at that button and see if I can see anything that looks loose or broken. Otherwise I'll ask my husband to open the hood and try to see where the relay wires are. He is the only one who knows how to open the hood (at the moment)!

Thanks again!
Mona

[the_experience03]

Follow the wires from that switch on the floor and you'll find the relay. A relay is baically just a big electro-mechanical switch designed to carry high amounts of current. The switch carries a small amount of current and activates the relay which carries the heavy current.

[lapeer20m]

my dimmer switch (i call it the bright light switch) on the floor was actually bad in my bus, giving me a similiar problem. I'd be driving along and the lights would just go out. I found that stomping on the switch would usually make them come back on.

the switch lives in a pretty harsh enviroment, especially if the bus came from land where it snows. Every day it snows, the driver sits down and his/her snow covered boots create water on the floor right where the switch is. After 10 or 15 years of this abuse it's not suprising that the switch would go bad.

dont rule out the relay that the previous post was suggesting. on my bus, the relay was under the hood not too far from where the drivers feet would be, just on the opposite side of the fire wall. I have a thomas body.

[monahowell]

You guys are so helpful! If I can find the problem and fix it I will be so proud of myself!

My buzzer on the back door went into always-on mode for some unknown reason and I actually figured out what part it was, found a site where I could order a new one, and kinda-sorta fixed it. Now it's always off - with an occasional buzz when the door is opened. I know it's supposed to buzz every time the door is opened, but I guess I didn't quite fix it all the way. At least it's not buzzing all day long.

Thanks so much everyone!

Mona

[wmah]

My door buzzer quit working on me after I disconnected it. I figured I didn't really need it since it is not being used as a school bus anymore.

[lapeer20m]

cutting the wires to that annoying buzzer is one of the first things i do when i get a new bus

[monahowell]

Ha Ha Ha -- yes, that was my FIRST thought. However, when I removed the offending buzzer at the door it was STILL buzzing up by the driver's seat and I had no idea where those wires were. So the next best thing was to fix the dang buzzer and at least I'd only have to hear it when the door was opened.

Crazy!