1983 MCI-9 Executive Coach Corp. Conversion lv question

chrisj1226 · March 03, 2017, 08:38:06 PM

I have two switches side by side. One has the label 12 volt merge. The next has 24 volt merge. I have no clue what they are about, and I'd prefer not to cause myself expenses due to stupidity. Could someone please explain this to me. I know the chassis side is 24v and the house side is 12v. I don't know why I would need to merge them, and why there are two switches.
Also if anyone has a conversion by Executive Motor Coach Corp. I'd really like to be in touch with them.

blue_goose · March 04, 2017, 04:20:58 AM

Lowell Snyder has a Custom Coach conversion about the same year as yours. He may be able to help.
Jack

Answered to soon, you have and Executive and his is a Custom.

Rick 74 MC-8 · March 04, 2017, 07:24:11 PM

I have a 74 executive coach. I don't have merge switches but I do have I a switch marked battery charging relay. It Triggers a relay in the battery compartment that connects the 12 volt side of the Vanner equalizer to the 12-volt house Bank

Rick

bigred · March 05, 2017, 07:16:04 AM

I saw one of these advertised for sale some where.I figured you could contact the owner for some info ,but I've checked all my usual haunts and I can't find it so it must have already been sold or I blundered on to some site by accident .I don't even remember what model it was.

Geoff · March 05, 2017, 08:34:32 AM

Trucks that had 12v lights and a 12v alternator used to use a "series parallel switch" which powered a 24v starter off a 12v battery bank. I have one sitting around that I could hook up but I just jump the 24v off one side of the 12v house system if I have low 24v starting batteries. Do a Google search and you will find a SPW. It uses a lot of wires.

--Geoff

Oonrahnjay · March 05, 2017, 09:00:13 AM

Quote from: Geoff on March 05, 2017, 08:34:32 AMTrucks that had 12v lights and a 12v alternator used to use a "series parallel switch" which powered a 24v starter off a 12v battery bank. I have one sitting around that I could hook up but I just jump the 24v off one side of the 12v house system if I have low 24v starting batteries. Do a Google search and you will find a SPW. It uses a lot of wires.
--Geoff

Here's one. Yes, it uses lots of wires but -- my bigger question, does it work reliably?
http://www.texasindustrialelectric.com/relays_1119845.asp

I used to know a "party bus" operator who ran big-watt lighting and sound systems on his buses by just jumping off on 12V side of the 24V pair of 8Ds in series. I guess he liked being called at 1:30 in the morning "we're at the strip club and the bus won't start"; he would take his "start box" to the dead bus, put it on one of the 8Ds, and that would fire the bus starter off just fine. (I'm sure that the engine was at least warm, and at least one battery had a fair amount of charge still left, etc. so it's a pretty light-load situation, but without at least that jump box, those buses weren't going anywhere.)
What do you think of this procedure, Geoff?

Geoff · March 05, 2017, 09:31:13 AM

It is very reliable, however I do remember changing one or two. It was used for many years on trucks before technology developed a strong cranking 12v starter so 24v starters weren't needed anymore.
As far as buses go, they kept the 24v starters since that was the main power source for the air conditioning and heating systems. I don't know what the newer buses use, all the buses I work on are over 20-25 years old. I'm sure someone knows that answer.

--Geoff

luvrbus · March 05, 2017, 09:57:18 AM

The MCI D has a master switch that merges the 2 systems when flipped on through the Vanner the 24v side is for the engine components and Hvac system the 12v side is for the lights and other 12v items in the bus

Oonrahnjay · March 05, 2017, 05:48:09 PM

Quote from: luvrbus on March 05, 2017, 09:57:18 AMThe MCI D has a master switch that merges the 2 systems when flipped on through the Vanner the 24v side is for the engine components and Hvac system the 12v side is for the lights and other 12v items in the bus

The Low-Floor Gillig is similar.

Geoff · March 05, 2017, 06:26:16 PM

Well, my original 1982 RTS didn't have a Vanner equalizer (if they were even built then); it used some kind of 24v regulator that also produced just enough 12v amps to keep the center tap of 2 of the 4 batteries charged enough to keep all four batteries charged equally with the 270 amp hand grenade alternator. Damn, that was a mouthful. Add it to worthless information (unless you run an RTS).

--Geoff

eagle19952 · March 05, 2017, 06:56:23 PM

Quote from: Oonrahnjay on March 05, 2017, 09:00:13 AM
Here's one. Yes, it uses lots of wires but -- my bigger question, does it work reliably?
http://www.texasindustrialelectric.com/relays_1119845.asp

The only bad part about them was the people who called themselves mechanics but did not understand them...straightening out the wiring after the hacks hacked them, that could be a problemo......

Oonrahnjay · March 06, 2017, 03:13:39 AM

Quote from: eagle19952 on March 05, 2017, 06:56:23 PMThe only bad part about them was the people who called themselves mechanics but did not understand them...straightening out the wiring after the hacks hacked them, that could be a problemo......

Thanks, Don (and Geoff). I have the issue of putting my charging system together after I finish installing the Cummins ISC in my bus. I have the Vanner (I'm pretty sure it's 100 Amps from the 12V side) from the donor Gillig. I'll be running 8 or 10 surplus AGM 12V batteries from a cell tower (written off as surplus but still taking a charge and holding it very well) as my house battery bank; my interior lights are 12V LED, my fridge is 12V Novacool. I'm guessing that the Vanner is all I need but with the 250 Amp oil-cooled (belt driven) alternator on the Cummins, I'll have plenty of juice from the engine. I've been running a 12V - 2000 watt Outback inverter but I'm feeling that (as I look at my real life loads) that that might have been a mistake -- a larger watt 24V inverter might work better for what I need, but it's a question as to whether it's worth the financial hit to change it.
I don't quite know how the 24V - 12V series parallel switch might work for me yet, but it's good to know that it's available if I need it.
Thanks for the help as I work through my questions.

Geoff · March 06, 2017, 07:56:59 AM

Quote from: Oonrahnjay on March 06, 2017, 03:13:39 AM
Thanks, Don (and Geoff). I have the issue of putting my charging system together after I finish installing the Cummins ISC in my bus. I have the Vanner (I'm pretty sure it's 100 Amps from the 12V side) from the donor Gillig. I'll be running 8 or 10 surplus AGM 12V batteries from a cell tower (written off as surplus but still taking a charge and holding it very well) as my house battery bank; my interior lights are 12V LED, my fridge is 12V Novacool. I'm guessing that the Vanner is all I need but with the 250 Amp oil-cooled (belt driven) alternator on the Cummins, I'll have plenty of juice from the engine. I've been running a 12V - 2000 watt Outback inverter but I'm feeling that (as I look at my real life loads) that that might have been a mistake -- a larger watt 24V inverter might work better for what I need, but it's a question as to whether it's worth the financial hit to change it.
I don't quite know how the 24V - 12V series parallel switch might work for me yet, but it's good to know that it's available if I need it.
Thanks for the help as I work through my questions.

With your donor electrical system you have the typical setup to run the factory over the road heating and air conditioning (HVAC) system. The RV world uses everything 12v and 120v (air conditioners) so the donor 24v system is way overkill unless you want a huge 24v inverter. My choice was to remove the D50 24v alternator and use a 160 amp 12v alternator and 40 amp 24v alternator. I use a 12v inverter that can run one roof air, and a 8kW genset if I need to run 2-3 roof airs. When parked, the inverter uses shore power or the genset to run everything plus charge the batteries. I have a very good system that has served me well for 12+ years.

You could use a SP switch and have only house batteries. I am thinking of doing this so I could have four more golf cart batteries in my house system. I only have four golf cart batteries now and it is not enough to keep my Webasto running all night. What has held me back is the price of replacing 8 golf cart batteries every 5-7 years at a cost of $800.

--Geoff

buswarrior · March 06, 2017, 09:47:36 AM

FWIW, Vanner equalizers were used in the 1990 Flyer D40-90 models.

That's where I found my pair.

happy coaching!
buswarrior

Oonrahnjay · March 06, 2017, 10:15:26 AM

Quote from: Geoff on March 06, 2017, 07:56:59 AM
With your donor electrical system you have the typical setup to run the factory over the road heating and air conditioning (HVAC) system. The RV world uses everything 12v and 120v (air conditioners) so the donor 24v system is way overkill unless you want a huge 24v inverter. My choice was to remove the D50 24v alternator and use a 160 amp 12v alternator and 40 amp 24v alternator. I use a 12v inverter that can run one roof air, and a 8kW genset if I need to run 2-3 roof airs. When parked, the inverter uses shore power or the genset to run everything plus charge the batteries. I have a very good system that has served me well for 12+ years.

You could use a SP switch and have only house batteries. I am thinking of doing this so I could have four more golf cart batteries in my house system. I only have four golf cart batteries now and it is not enough to keep my Webasto running all night. What has held me back is the price of replacing 8 golf cart batteries every 5-7 years at a cost of $800.

--Geoff

Thanks, Geoff. I had been looking at the idea of "changing down" on the big alternator, too. There is lots of space for a second alternator and a pretty easy bracket setup. Thanks for the info.