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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: edwin b on February 03, 2009, 04:37:21 PM

Title: 04 trailer lights
Post by: edwin b on February 03, 2009, 04:37:21 PM
Getting ready for daytona bike and having touble with the trailer lights.  I thought i saw posted here once of a certain way you have to wire to trailer on the gmc 4104.  Can anyone help?
Thanks
edwin b
4104-230
Title: Re: 04 trailer lights
Post by: JackConrad on February 04, 2009, 06:12:38 AM
Quote from: edwin b on February 03, 2009, 04:37:21 PM
Getting ready for daytona bike and having touble with the trailer lights.  I thought i saw posted here once of a certain way you have to wire to trailer on the gmc 4104.  Can anyone help?
Thanks
edwin b
4104-230

If your bus has separate brake and turn signal lights, you will have to install relays to allow both turn and brake lights to feed a single bulb on the traier without backfeeding or add an additional bulb on each side of the trailer.  Jack

PS: you would only need 3 relays (left turn, right turn, and brake) The marker relay is to convert MC-8s 24 volt to 12 volt.
Title: Re: 04 trailer lights
Post by: uncle ned on February 04, 2009, 07:18:11 AM


On my 04 the brake and tail light are togather   just ran a wire from the left brake and the right brake and the tail light  to a four wire plug.

Where in daytona are you planning on parking. We usualy park in the west parking lot at the speedway bu t last year they wanted $300 for the bus and $300 for the trailer. Seems like they are getting to greedy and the new tunnel sends the night traffic right through the lot.

uncle ned
huggy bear.

ps Pat Mcneil has a personal parking place for his big red bus. Might want to talk to him and get close
Title: Re: 04 trailer lights
Post by: edwin b on February 04, 2009, 10:20:55 AM
Thanks Guys.
I'm staying in Ormand Beach at the encore camp ground.  Haven't stayed there before. They quoted me at 57 bucks a night with trailer.  Hope to be there friday night the 27th. Looking forward to it after this winter!  10 degrees and snowing right now!
thanks again for the help.
edwin b
4104-230
Title: Re: 04 trailer lights
Post by: edwin b on February 05, 2009, 10:36:54 AM
jack
do you have the voltage and amps for the relays? maybe the manufacturer also? 
Thanks
edwin b
4104-230
Title: Re: 04 trailer lights
Post by: JackConrad on February 05, 2009, 02:02:08 PM
They are standard 30 amp cube relays. I buy them on Ebay, but any local car audio place should have, probably also available at NAPA, Discount, PepBoys, etc. as well as Radio Shack.  For a 4104, you would need 12 volt version. For a bus with a 24 volt systems, you will need the 24 volt version.  Here is a wiring schematic. The marker light relay is not neccessary unless you coach is 24 volt.  Jack
Title: Re: 04 trailer lights
Post by: Charles in SC on February 05, 2009, 06:17:17 PM
I do not see why you could not use one of the converter boxes made for that purpose. They are available at places like Advance Auto. They have diodes that do the work of the relays and are very easy to install. I have one on my 5303 that converts 4 wire system to a 3 wire.
Title: Re: 04 trailer lights
Post by: belfert on February 06, 2009, 05:01:38 AM
I used a powered converter for my trailer lights.  It will combine the brake and tail lights plus it takes power from a 12 volt source so you aren't pulling power for the trailer lights through your lighting circuits.

My brake lights are already marginal as far as the wiring goes and I didn't want to add two more brake lights.
Title: Re: 04 trailer lights
Post by: JackConrad on February 06, 2009, 05:43:56 AM
Quote from: Charles in SC on February 05, 2009, 06:17:17 PM
I do not see why you could not use one of the converter boxes made for that purpose. They are available at places like Advance Auto. They have diodes that do the work of the relays and are very easy to install. I have one on my 5303 that converts 4 wire system to a 3 wire.

Those converters work OK as long as your bus is not 24 volt.  Jack
Title: Re: 04 trailer lights
Post by: rv_safetyman on February 06, 2009, 10:02:39 AM
I just submitted an article to BC magazine on this subject.  The system is exactly like Jack posted. 

I will paste below the part that discusses the relays:

>>>>>>>paste from BC article submission>>>>

Before we talk about the relay based converter system, let's talk about the Bosch-type automotive-type relay.  It is a standard relay used extensively in the bus and heavy truck market.  Several manufacturers make this relay and most rate them for a one million mechanical cycle life, minimum.  The relay is typically described as an ISO standard automotive relay.  They are very inexpensive and readily available.  These relays come in many versions including weatherproof, with diodes across the coil, with/without mounting tabs, etc.  Some sources are:

Digi-Key (www.digikey.com)
Tyco, part number PB682-ND (12V with diode)
Tyco, part number PB684-ND (24V with diode)

Del City (www.delcity.net)
73986 (12V with diode)
73570 wired socket only

I have listed relays that have built-in diodes connected to the coil terminals.  The diodes prevent voltage spikes when the relay coil is de-energized.  For this application, that would probably not be an issue, but the added cost is negligible.  Relays with diodes are polarity sensitive.  The coil connections must be wired so that terminal 85 is the ground terminal and terminal 86 is the signal.  These relays are not weatherproof, so they should be mounted in an enclosure or an area not subjected to significant amounts of fluids.  The relays are less than $5.

>>>>>>>>>>>end paste>>>>>>>>

The system works for either 24V or 12V.  You just need to have the correct voltage relay.

Jim
Title: Re: 04 trailer lights
Post by: edwin b on February 13, 2009, 11:28:14 AM
Thanks guys.  I just got the relays. 
belfert
what kind of powered converter did you use?
i would like  an alternate power source for the trailer.
edwin b
4104-230