I believe the PO required the headlights to 12v based on the headlights in there now are General Electric with a 1C1 or 2C1 stamp. Best I can research these are 12v.
I remember the bus has always had real dim lights.
I received some lights from a guy dumping his MCI stuff and got these Wagner 4579 and 4814 headlights from him. They are a good physical match and are labeled 28v.
Wouldn't you know my maintenance manual has a section missing from page 7-31 through to the end of electrical is missing. I have found post 33 on the front panel for the headlights and will get a voltage test on the connectors if I can trace them. I remember it being 12v last time I checked.
If anyone has the page showing the headlight wiring it would help me out. Not sure where the section 7 through 11 went on this book.
Someone posted a wiring diagram a couple of months ago.
OEM MC-7 headlights were 24vdc.
MCI didn't switch to using 12vdc headlights until MC-9s, with a weird wiring set-up that actually works well, when folk take the time to thoroughly understand it.
IIRC, there's a technical bulletin on MCI's website for converting 24 to 12 operation, including the wiring schematics. Or give MCI Tech Support a call and ask them to send you a copy.
FWIW & HTH. . .
;)
Quote from: RJ on July 27, 2016, 07:09:28 PM
MCI didn't switch to using 12vdc headlights until MC-9s, with a weird wiring set-up that actually works well, when folk take the time to thoroughly understand it.
My 1978 MCI 8 has 12v but mine is a late 8 with some weird combinations. Probably between 8 and 9. I can't keep them from burning out too! HAHA
FWIW
It's a wild goose chase. I currently have no volts to the lights.
Looking underneath the driver seat there is a cobbled mess of disconnected wires and a physically broken fuse/breaker thing. Not sure what they are called but they seem to work like self healing breakers.
I will get back at it tomorrow and hopefully trace back to some voltage.
Anyone have thoughts on if the 12v setup will be more bright than the 28v?
Very possible the problem is a poor ground connection
The PO of my bus just put in a small 24v to 12v converter box to run the 12v headlights off of.
GOOD MORNING DAVE,I HAVE A 69 MC7. I WENT ALL THRU THE 24VOLT HEADLITE PROBLEMS. THEY ONLY PUT OUT 55 WATTS. NOT GREAT FOR DRIVING 70 MPH AT NITE.YOU OUTRUN THE LIGHTING . I CHANGED MY COACH OVER WITH JUST TWO SOLENOID'S & ABOUT 1 FOOT OF WIRE. HAS BEEN DONE 8-10 YEARS AGO WITH NO PROBLEM.NOW I USE HALIGEN HEADLITES. WHAT A DIFFERENCE. I ALSO HAVE THE PAGES IN MY BOOKS. SEND ME YOUR # & I CAN FAX YOU BOTH SHEETS. DOC 863-660 2477 OR RESTINN@TAMPABAY.RR.COM
I had a factory MCI conversion kit that had two little adaptor boxes, one for each side, that converted 24v to 12 v. Worked, but badly. I took that out and installed Cebie lights with 28 volt Halogen bulbs. I believe these are about as good as you get with the little 4" by 6" square bulbs that I have (there is a conversion from four round headlights installed).
If you just need to get the 24v lights working there is a junction on the floor under the "brights" foot button (you will have to remove the stainless panel to get at the wiring. Check the relay first (on the front junction panel) ...If it has been sitting in any sort of humidity they tend to get "the green growies" and clap out. If the relay ohms out then check under the panel...after that its a straight shot through the floor to the light ballasts. If they have been converted to 12v it is common to find a voltage drop box of some kind under the dash or near the fire extinguisher mount to the right of the defrost blower box, or even in the tool compartment. Hopefully you have a relay print on the backside of your junction cover. PM me if you need a wiring diagram...I have a 7 book laying around somewhere.