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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: gm4106 on November 11, 2007, 10:17:05 AM

Title: towdolly wiring connections
Post by: gm4106 on November 11, 2007, 10:17:05 AM
I'm trying to wire my tow dolly. My setup for the toydolly is a 4 plug set up; white is ground, brown for tail lights, yellow for left turn/stop and green for right turn\stop.

My bus brake lights are separate from my bus turn signals, how should my connections be wired?  Do I need to purchase any kind of adapters?
Title: Re: towdolly wiring connections
Post by: white-eagle on November 11, 2007, 10:48:56 AM
i did.  i bought an adaptor at NAPA for about $25.  it also adds power to the lights in case your switches don't or won't handle it.

Title: Re: towdolly wiring connections
Post by: Utahclaimjumper on November 11, 2007, 12:13:33 PM
GM, pick up the power at each lite from each individual lite plug at the back of your tail gate, run down to the plug and plug in at that point, ( left,right, brake,and tail.)>>>Dan
Title: Re: towdolly wiring connections
Post by: TomC on November 11, 2007, 01:17:54 PM
I changed to 5 wire so I could have ground, running, stop, right, left.  I use two sets of LED magnetic lights which are extremely bright, and am very satisfied with the performance.  May not look as neat as the lights on the car, but it gets everyone's attention.  Good Luck, TomC
Title: Re: towdolly wiring connections
Post by: Sam 4106 on November 11, 2007, 01:26:58 PM
Hi gm4106,
Unless your 4106 is wired differently than mine, you do NOT need an adapter. On mine, the tail lights are seperate from the brake/turn signals. The two small red lenses are for the tail lights and the two large red lenses are for the brake/turn signals.
Good luck, Sam 4106
Title: Re: towdolly wiring connections
Post by: gm4106 on November 11, 2007, 03:07:48 PM
I'm just thinking that the brake and trun's are septerate.
If I add a brake line to the left trun and right turn will that work right
Title: Re: towdolly wiring connections
Post by: baker4106 on November 12, 2007, 06:28:37 AM
You will have to add an adapter or run wires and add another light on each side for brake or turn signal.   I added a light on each side for brakes after trying an adapter and it only worked for a couple months.    Larry 4106-038
Title: Re: towdolly wiring connections
Post by: Sam 4106 on November 12, 2007, 10:04:55 AM
Hi gm4106,
Do you have the original engine cover with original lights or do you have an aftermarket engine cover and non-original lights? If you have an aftermarket engine cover and non-original lights with red stop light lenses and orange turn signal lenses, which would have seperate brake and turn signal bulbs, then you need an adapter.
Good luck, Sam 4106
Title: Re: towdolly wiring connections
Post by: gm4106 on November 12, 2007, 02:45:39 PM
OK thanks for all the input. Looks like I needed the adapter for the lights to work right.
Title: Re: towdolly wiring connections
Post by: Jerry Liebler on November 12, 2007, 07:09:23 PM
Since the bus has separate brake lights and turn signal lights and the towed or trailer has a single light that must serve both as a brake light and a turn signal you will need an adapter.  The adapter cannot be made of just diodes!  It must contain at least 3 SPDT relays.  If the bus is 24 volt, using 24 volt coiled relays and a source of 12 volt power with the same converter also handles 24 volt to 12 volt conversion.   From the bus the left turn bulb is paralleled with a relay, similarly the right turn signal bulb is paralleled with another relay and the brake bulb is paralleled with the third.  The common contacts of each of the turn signal relays go to the respective bulb on the towed.  The common contact of the brake relay is connected to 12 volt power.  The normally closed contacts of the turn signal relays are connected to each other and the normally open contact of the brake relay.  And the normally open contacts of the turn signal relays are connected to each other and the normally closed contact of the brake relay.
Regards
Jerry 4107 1120
Title: Re: towdolly wiring connections
Post by: DrivingMissLazy on November 13, 2007, 05:42:54 AM
Most auto parts houses sell an adapter that permits connecting a trailer wired for connection to an American wired trailer to connect to a foreign wired automobile, like a Japanese car. In other words a three wire trailer to a four wire automobile.

These are only available for 12 volt vehicles. Cost was about ten dollars the last time I bought one. Extremely simple to hook up and very reliable. I used on in my Eagle for at least 15 years with no problem.

These are for use when towing an American vehicle behind a 12 volt bus. An American vehicle is described as using the same bulb for brake and turn signal light. You can never have a left turn signal and drivers side brake light on at the same time.

Most, if not all, buses are wired like foreign automobiles and have turn signal bulbs separate from the brake signal bulbs. In this case you can have a left turn signal on and at the same time have a drivers side brake light on at the same time.

Richard