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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: busmanted on June 07, 2007, 06:16:15 PM

Title: Headlights in series and my confused brain!
Post by: busmanted on June 07, 2007, 06:16:15 PM
MC8 with R & M kits, 4 headlight system w/12v rectangular headlights. If you are not familiar w/4 lamp system...the inside lights are High Beam only and the outside lights are Low/High Beam, all sealed beam bulbs. I am trying to figure out how to wire these headlights in series. Since the High and Low Beam share a common ground on the outside lights, I cannot summon enough brain power to come up with a plan... other than leaving the High Beam on the outside light disconnected. Then it's easy. Thanks in advance for any help. Busmanted
Title: Re: Headlights in series and my confused brain!
Post by: gumpy on June 07, 2007, 06:27:12 PM
Look at the MC9 schematic. It will show you exactly how it should be wired.

If you 8 hasn't been upgraded to MC9 headlight wiring, now is the time. There's a bulletin on how to do it from MCI. Don't have the link, but someone will have it, I'm sure, and will post it here soon.

Title: Re: Headlights in series and my confused brain!
Post by: Ncbob on June 11, 2007, 04:43:55 AM
Just a casual question....will the 12V Halogen sealed beams be brighter in a 24V series connection than they would be in a 12V configuration?

I normally don't do much night driving in the bus but my square 12V sealed beam Halogens are like someone holding two candles.

Just thought I'd ask.....

NCbob
Title: Re: Headlights in series and my confused brain!
Post by: Jerry32 on June 11, 2007, 04:55:49 AM
I think it's all relative to the voltage at the lights. have you checked it?? a bad ground or loss in the wiring can cause this. There should be no difference between 12 an 24 volts. Jerry
Title: Re: Headlights in series and my confused brain!
Post by: Len Silva on June 11, 2007, 07:08:40 AM
Here is some info from MCI
http://www.mcicoach.com/parts-service-support/serinfo/serinfo07G.htm

Here is the bulletin 1930
http://www.mcicoach.com/parts-service-support/serinfo/serbull/1930.pdf

Len
Title: Re: Headlights in series and my confused brain!
Post by: Stan on June 11, 2007, 07:28:43 AM
LEN: A couple of problems with your circuit. Without a diode in the 12 volt tap. all the lights are on all the time without any way to turn them off. The second problem is that the right hand lights (on your drawing) have all filaments in parallel and then in series to the left hand filaments. This will give you a dim left hand light and a very bright high and low (at the same time) on the right hand side. Your drawing needs more work.  Have a look at the MCI 12 volt headlamp system on 24 volts.
Title: Re: Headlights in series and my confused brain!
Post by: Len Silva on June 11, 2007, 08:31:12 AM
Stan,

You are quick.  I only had that circuit posted for about 30 seconds before I realized it was wrong.  I posted the MCI bulletin instead.

Len