Headlights: Dumb Question

[PP]

My running lights and headlights quit working today, luckily while it was still light out. When I opened up the buss box to check for blown fuses, I couldn't find any typical little glass fuses like I have in my car. What should I be looking for? Please, help. I didn't realize how stupid I was! Thanks

[pete81eaglefanasty]

 What kind of bus do you have, And what model ? It will help a lot.

           Pete & Jean
             FANTASY

[tekebird]

I would guess a Prevost my his ID......

 might have resetable circuit breakers....they do go bad from time to time

[PP]

I thought I would recognize circuit breakers and fuses, but I'm not recognizing anything in the front electrical panel except a whole lot of connectors. I have 2 panels of breakers for the coach inside (1-AC & 1 DC).

[buswarrior]

a self resetting circuit breaker is just a little metal box with two connectors.

Or you might have a broken or disconnected wire.

If you have the wiring diagrams, start tracing the lighting circuit, and confirm power at every junction point along the way.

Check the inside of the electric panel door for a diagram, or your maintenance manuals

a multi-meter is a busnuts good friend!

Let us know!

happy coaching!
buswarrior

[gumpy]

I'm not trying to be a wiseass or anything, but how long have you owned this bus? 

I'm going to guess you didn't convert it yourself?

Do you have manuals and wiring diagrams?

Do you have a volt meter?  Do you have any experience with automotive electricals?

We're gonna need a bit more background on you and your coach to help. There are many possible gremlins that could
cause this. Most likely are switches, and breakers, and relays.

craig
 

[Hi yo silver]

I suggest you check the headlight switch first.  If you can access the back of the switch, just take a look to make sure you don't have a wire loose or broken.  The HL switch probably turns the marker lights on along with the headlights.  Also, I would think the headlights will be on an automatic resetting circuit breaker, while the marker lights are more likely to be on a fuse.  Just winging it here; whaddya think, guys?  Good luck, let us know what u find.
Dennis

[gumpy]

I suggest you check the headlight switch first.  If you can access the back of the switch, just take a look to make sure you don't have a wire loose or broken.  The HL switch probably turns the marker lights on along with the headlights.  Also, I would think the headlights will be on an automatic resetting circuit breaker, while the marker lights are more likely to be on a fuse.  Just winging it here; whaddya think, guys?  Good luck, let us know what u find.
Dennis

Yeah, sounds good to me. I'm not a Prevost guy, but that's the way the MCI works. Headlights turn on the markers, too, although there is a separate switch for markers, also.

This, of course, will be spelled out in a wiring diagram.

So, if you lost both, it could very easily be the switch or wiring to it.

[rv_safetyman]

PremiumPrevost, this thread has morphed into a pretty good thread on headlights.  Would you mind changing the title to include the word headlight so that it can be searched? Done. DML

I am not sure what the original Eagle headlight switch looked like, but I recall having problems with it.  I changed it over to an after-market switch.  I was recently installing relays on the headlights and must have momentarily shorted one of the leads.  In any case when I went to turn on the headlights, they would not work.  I did a lot of trouble shooting and nothing logical was found.  I then went to the switch and it had an old type fuse built into the top.  It had blown.  As others have said, that is a logical place to start looking.

The Eagle has fuses that are mounted like the old glass fuses, but they are larger with a black body.  The headlights have four of these and I have had a lot of problems getting good contact with the fuse tabs.  Nothing seems to improve that contact.  This caused a significant problem with the headlights, since they are relatively high current circuits (makes the problem worse).  At one time all four had bad contacts and that was a ton of fun to trouble shoot .  That is the reason I went to relays.  The old circuit only needs to pass enough current to trigger the relay.  I ran a heavy circuit to the relays from the main power supply (protected by a resetting circuit breaker).  It really seems to have improved the headlights (which were not much better than a candle previously).  The test will come later this week when we hit the road.

Changing the subject slightly, once you get the headlights working, you will probably find that they leave a lot to be desired (seems to be a common complaint on buses).  The Eagle has four round 5 3/4 headlights and I like the look.  Those headlights were not really good to begin with (with the fuse problem, they made driving at night a real white knuckle adventure!).  I have ordered some special European style units (not the obnoxious blue ones!!! ) from Daniel Stern (http://www.danielsternlighting.com/).  I ordered the CSR units (pricey), but they are out-of-stock, so I can't report on their performance.  I highly recommend this website.  Daniel appears to be an expert on headlights and his website is filled with good information.

Jim

[ChuckMC8]

PremiumPrevost- I have a set of manuals for your bus that will answer many questions that you either have or will have. If you are interested, email me at 14bama@bellsouth.net

[Reddog]

I don't know if this applies on a Prevost, but on the older Bluebirds, it is common to have headlight switches go out because they were forced to carry too may amps, especially if you had gone to Halogen headlights. A popular upgrade is to install a relay system so the switch carries very little amperage and the lines that actually fire the headlights are heavier than originally designed. This cures the switch problem and really lights the headlights much brighter. Here is a link to the wiring:
http://www.pbase.com/iamflagman/image/59743927
Good Luck and Happy New Year,
Doug Engel, Gunnison, CO

[Hi yo silver]

While we're on the subject of lights, the best auxilliary driving lights I have ever used are actually aircraft landing lights, intended for small private planes.  They are 12 volt sealed beam lamps, about 4 inches or so in diameter.  They fit "Unity" lights that we used to attach to bumpers back in the 50s and 60s.  I still have mine; I'm saving them for my bus!  I think all the hardware and replacement lamps are still available.  If anybody really, really, really wants particulars, send me a p.m. and I'll take one apart and give you part numbers. I think they are rated at about 100,000 candlepower.  They might not be any better than some modern stuff that's available out there, but they are the best I've had.  They do draw a pretty good load electrically, so relays work best for powering them. 

The fused headlight switches someone mentioned above might be mounted so the fuse is on the top, and the d##% switch is bound to be where you can't get your big head under it to see.  Might have to use a mirror.  Good luck.
Dennis   

[gumpy]

While we're on the subject of lights, the best auxilliary driving lights I have ever used are actually aircraft landing lights, intended for small private planes.  They are 12 volt sealed beam lamps, about 4 inches or so in diameter.  They fit "Unity" lights that we used to attach to bumpers back in the 50s and 60s. 

Hear! Hear!

You must be from deer country!

I've used aircraft landing lights on the front of my vehicles since my first one in the late 70s. I mount them in black rubber tractor/utility housings. Makes it easy to get in and out, and if you hit something, it won't ruin the housing. Might break the bulb, but you just install a new on in the rubber housing and you're good again.  I like to mount 4 on the front. The outside two are pointed towards the fences on either side of the road. The inner two are pointed down the road. Good for a mile or so of illumination. I miss them, because I live where there is too much traffic now, and you can't use high beams let alone aircraft lights!

I have intentions of putting 4 of them on the MC9. Maybe this spring I'll get that done.

[PP]

Wow, I wish I had found this site a long time ago! You're the first bunch of people that aren't only helpful, but you know what you're talking about. The minute you mentioned the little metal boxes, I realized I was looking at about 100 of them. The trusty ohm/voltmeter told me they were working. I have upgraded 4-light Halogens that work great. The headlight switch is a 3-position toggle. The back toggle position triggers a solenoid that powers the running lights. The forward position turns on all the lights. Center is off. Following the wires back (Yes, I do have a complete schematic on the bus-thank God) I found the problem in the tightest of places, in the housing with all the switches and too much wire to get your fingers in. A simple crimped connector let a wire from the switch loose, and all the lights quit. Laying on my back with a flashlight and feeling thankful that I'm near-sighted, I finally got the switch free and put on a new connector. Switched the batteries back on and everything is working fine. PS- I had a jeep back in the 70's that we used for offroading down in Tx and we all swore by aircraft landing lights, especially the army surplus type. I'm not sure if anything else was even available back then. Thanks again for everyone's help, you got me on the right track.

[buswarrior]

Thanks for the closure, PremiumPrevost!

Glad you've found a new home!

happy coaching!
buswarrior