Stock Heater Troubleshooting

[Rengald]

Hey all,

We've only had our bus for just over two weeks so I'm still learning all there is to know about it. We are in the midst of demo at the moment but I realized recently that I simply cannot get the heaters to actually blow hot air.

We've got a 71 passenger Bluebird International. I removed the heater in the back and looped the hoses as can be seen in the photo below. I'm fairly certain that there is coolant moving through the system because after I completed the loop there was a steady leak out of one hose until I tightened a clamp. I bled the system of air after changing the lines.



There are three valves in the system; two under the hood and one under the steering wheel. As far as I can tell they are all open but this brings up the question, "If only one valve is closed will that completely shut off they coolant flow? If so... why are there three and not just one?"

As far as I can tell, my coolant moves in a big loop through the door heater/blower and the heater/blower by the driver's seat and then back.

Under the hood I can feel one hose that is warm when the bus has been running but once it get's inside the cab the hose goes cool. The blowers all work but are just pushing cool air.



So that's where I am at. I've tried just about every switch on the dash and every combination of open/close valve position I can but still no heat...

I'm wondering if there's just something obvious here that I am missing? Any input anyone might have would be appreciated otherwise I'll be back out working on it/troubleshooting tomorrow.



Thanks in advance!

[turf]

is it a blower problem or lack of heat?

the red valve in the first picture is turned off. find all of those and turn them on.

my bus has 2 of those valves. they both need to be open for fluid to make the loop. ones is on top of the engine block, one is underneath on the transmission cooler.

the engine cooling system runs no matter how those valves are turned. they are to turn on the interior heating loop.

[Rengald]

Thanks for the reply, turf! I appreciate the confirmation on the valve orientation. Knowing which way is open for certain will definitely make troubleshooting easier.

The blowers definitely work, they just blow cold air, not warm.

Thanks!

[Robin97396]

Sometimes I'd like the valve to be inside where it was easier to reach.

Are your three valves each controlling a seperate heater loop?

[Rengald]

The three valves are all in the same loop; One on each side of the engine and one by the driver. I can't for the life of me understand why there needs to be three but I'm sure there's a good reason.

At this point I'm assuming the problem boils down to me just having a valve closed or some such thing. (I'm not proud of that fact but it's probably true) so tomorrow I'll sort it out.

Thanks everyone for your consideration.

[Rengald]

Hose coming out of engine and into door heater. First valve is here.

hoses come inside, though heater, and back out. you can see the hose coming out in the first picture. it goes across the "nose" of the bus under the windshield.
.
after crossing across the bus, the heater lines go back inside to the driver's side heater.

this is the second valve by the driver. the lines go through this heater and would go back to the additional heater had I not removed it.They then return back outside and to the engine with one more valve along the way.

Just figured I'd share a few pictures in case that changes anything. At the very least it might clarify my system... and everyone likes pictures... right?

[Robin97396]

I think you're exactly right. At least one of the valves is closed. It's kind of comical in a way, you've got to admit. It's like playing an old slot machine to get heat. It's good to get the old bubble gum out of those heaters.

Of all the junk I cleaned out of my bus there was not one coin hidden anywhere. Just gum and wrappers.

[Rengald]

Haha well the humor of the situation is not lost on me. Of all the serious problems I could be having with the system... I just can't seem to find which way a valve needs to be for open/close. Its moments like these where I can only laugh at myself and be thankful it's nothing to serious (yet)...

Side note: is the button on my dash labeled "HTR PUMP" actually a heater pump? Because I've discovered that the "HTR MASTER" button has nothing to do with heater and now I'm questioning the alleigence of all my buttons...

[BlackJohn]

Originally Posted by Rengald

Haha well the humor of the situation is not lost on me. Of all the serious problems I could be having with the system... I just can't seem to find which way a valve needs to be for open/close. Its moments like these where I can only laugh at myself and be thankful it's nothing to serious (yet)...

Side note: is the button on my dash labeled "HTR PUMP" actually a heater pump? Because I've discovered that the "HTR MASTER" button has nothing to do with heater and now I'm questioning the alleigence of all my buttons...

Usually with a valve, the orientation of the handle tells whether it is open or closed, unless it's a wheel naturally. If the handles like you have on your bus heating are in line with the hoses they should be open and if at right angle to the hoses, they be closed.

The HTR PUMP is not always installed but a definite possibility, like an option. You have to physically locate it then check for power, valves open through it etc.

The HTR MASTER switch may provide power to the pump as well as the fans when in the "ON" position. Could be that it is just in the dash to fill that space or hole in the dash panel. You would have to open the panel and do some investigating and testing. Maybe disconnect the batteries first because the chance of shorting something out is high with so many wires to the back of that panel. Just check for 12v to ground on the master and pump connections once you can connect the batteries back up after opening the panel and letting it rest so you can see the wiring without disturbing anything. Post some pics if you are able.

[Robin97396]

I've heard the larger buses often have auxilary pumps for their rear heaters. It makes sense that there would be a switch so when the heating loop is shut off, during the summer months, the pump isn't automatically running all the time.

[SimplyUs]

Hey Regald, my name is Nate. So about a little over a month ago we went to a place called the voyageur bus company in Duluth MN to look at school buses for our conversion. We spoke with a guy named Ryan. when we first showed up, asking to look at their school buses to do a conversion, the front desk guy and Ryan both looked at each with kind of a smile. I asked them both, what's up? Is it unusual for people to come here to ask if you sell buses? Ryan said no, your just the second couple this week to come look at a bus for a conversion. He said it was a couple that are living in Duluth. If I'm not mistaken you are the couple he was talking about. We are currently in the process of purchasing our bus from there and would love to meet up and exchange ideas and tips. Contact me if you are interested. Thanks! Also this is my first time using this forum so I don't really know how it works.

[theHappinessBus]

Hello Rengald and others,
Currently working on removing my rear heater lines and also troubleshooting the drivers control panel. Gonna take everything apart soon and discover what is or isnt still connected. So far, i dont seem to have power to heaters or radio, and there are about 20 other switches that seem to have no function and only cryptic letters to describe their original purpose.
Any idea where the electric lines to the rear lights are running? Im guessing the ceiling, but there are also two skinny orange wires running alongside the rear heater hoses. Want to remove these, but not sure what they are yet!

May post some more specific questions soon,
I would like to remove the drivers side heater entirely if possible, especially if i cant get it to work at all... Any foreseeable problems with this plan? And any advice on looping those hoses? Have never done anything with bus heating/electrical system...

Thanks

[kazetsukai]

I had to reinstall the heater in my RE rig.


For engine heat you need two things: Hot coolant flowing and a working liquid-to-air heat exchanger. If the heater isn't getting warm you have no flow, maybe no coolant.There can be two valves- one to shut off flow in the engine compartment and one to regulate flow as to control the temperature, the latter being cable-driven. I swapped out the temperature control valve for PWM motor control.

If you open coolant lines again make sure you do not deplete your coolant reservoir running afterwards. Also, booster pumps are a thing, especially for bigger rigs. Usually a switch on the dash, make sure it is getting power and working.

If the heater is warming up but not blowing hot air its likely a fan/electrical issue.

[theHappinessBus]

Thank You, that is helpful in understanding the system as a whole... Now, if i were to remove the rear lines to my system, I can cut the hoses at some reasonable length and just loop them into each other? Is there some sort of fitting for this? And do i have to be worried about coolant flowing everywhere... bleeding the air out of the system?

All new to me. Will be doing some research elsewhere i suppose, but any advice appreciated...

Just for reference, my system is almost identical to the one in Rengalds pictures.

[kazetsukai]

Originally Posted by theHappinessBus

Thank You, that is helpful in understanding the system as a whole... Now, if i were to remove the rear lines to my system, I can cut the hoses at some reasonable length and just loop them into each other?

Brass barb fittings of the same ID should work with hose clamps.


As for air, just make sure your reservoir doesn't deplete below minimum, the air will be pushed through by the coolant pump into the reservoir. Happened to me when I reinstalled my lines.


If you really want to be safe, take the rig in for a coolant flush somewhere.

[Booyah45828]

Originally Posted by theHappinessBus

So far, i dont seem to have power to heaters or radio, and there are about 20 other switches that seem to have no function and only cryptic letters to describe their original purpose.

Check for blown fuses. If none are, use a test light to see if you have power into and out of any switch. Describe the cryptic letters that you're referring to, or take a picture of them for us to figure out. Buses have a lot of switch to control various lights in the bus that you'll no longer need or use.

Originally Posted by theHappinessBus

Any idea where the electric lines to the rear lights are running? Im guessing the ceiling, but there are also two skinny orange wires running alongside the rear heater hoses. Want to remove these, but not sure what they are yet!

In the ceiling is correct, typically a little above the left/drivers side windows.

Those wires running along the hoses are probably for the high and low speed
power wires for the heater fan. The fan will ground through the seat it was attached under. If you removed the seat, make sure it's electrically grounded to the body/frame properly, or it won't operate.

Originally Posted by theHappinessBus

I would like to remove the drivers side heater entirely if possible, especially if i cant get it to work at all... Any foreseeable problems with this plan? And any advice on looping those hoses? Have never done anything with bus heating/electrical system...

Many people do that. It frees up space in the bus floor plan. The only time you'll have issues is if it's cold and need the heat back there.

What isn't working with the heater? You can loop the hoses, but I would remove them altogether and hook your return right to the front heater, eliminating the hoses to the rear heater altogether. That way you'd have fewer leak points.

[theHappinessBus]

Originally Posted by Booyah45828

What isn't working with the heater? You can loop the hoses, but I would remove them altogether and hook your return right to the front heater, eliminating the hoses to the rear heater altogether. That way you'd have fewer leak points.

Nothing wrong with the Driver's side heater, but the rear heater unit was removed in the previous owners conversion, though i cant get to the end of the rear hoses, because of the framing and flooring already installed. I would guess they looped them in the back and then left the hose and worked around it. Hope so...
In an effort to gain a little more floorspace and less space for little critters to dwell,
(Ive already cleaned out a few mousey apartments in the walls and behind the front heater blower motor ) id like to cut out a large section of the hoses, and loop them at the main heater.
Before i cut them open, how do i ensure the least amount of coolant leakage... and how to determine the direction of coolant flow? Does it start at the engine block (top hose) and then return in the bottom hose to the coolant tank? or vice versa...

[Booyah45828]

Originally Posted by theHappinessBus

Before i cut them open, how do i ensure the least amount of coolant leakage... and how to determine the direction of coolant flow? Does it start at the engine block (top hose) and then return in the bottom hose to the coolant tank? or vice versa...

If you have a large wet/dry shop vac, you can disconnect the hoses outside the bus in your picture right here at those copper elbows
and then use the shop vac to suck as much coolant from those elbows as possible. The more you remove outside, the less there will be to clean up inside.

You'll have to trace/follow hoses to determine coolant flow. From your pictures, it looks like hot coolant flows out of the cylinder head into the blue hose. That hose goes to the top valve, to a black hose, and then across the top of the engine to the top elbow on the driver's side. It then goes inside the bus, past the valve whose handle is missing, and through the driver's floor/defrost heater. After that it looks to go into the hoses for the rear floor heater, and then back up front, out the firewall and into the lower elbow. From the lower elbow, it looks to go across the the top of the engine and to the top elbow on the passenger side. From there, it goes into the firewall, through the passenger side defroster, and back out the firewall to the lower elbow on the passenger side. From that lower elbow, it then goes to your lower valve, where it returns to the engine, likely somewhere near the water pump.

If you're looking to remove the rear heater coolant hoses. Follow my picture here


Loosen the orange circled hose clamp, and remove the elbow from the hose. Then loosen the yellow circled hose clamp, and remove the hose from that elbow. Then, if they'll reach, connect the elbow at the yellow circle to the hose at the orange circle. If they won't reach, loosen the green circled hose clamp and replace that short section of hose with a longer piece and try again. After that's looped, you should be able to remove the rear heater hoses.

You might have to remove the flooring in the back where the rear heater was to get access to the heater loop they made. They might not pull through together with the flooring over it, or they might be fastened by the factory to the steel floor.

[theHappinessBus]

Thanks for the help. Seems like success with the heater lines. I cut, drained and removed the excess and looped the lines back to the system. Ran the bus for 10 minutes or so and it seemed to be heating well. Unfortunately, i then left the bus for a couple hours, came back and it wouldnt start...

Seemed like signs of low battery. The "wait to start" light comes on and a red "oil/water" light comes on briefly, and by the time i turn the key, there is only the slightest click, then nothing. I tried jumping from my GMC 3500 Van, but after 45 minutes, checking and trying to start every 10 or 15, i couldnt seem to get enough power to get more than a click at turnkey... hoping that this is just a seperate electrical issue, but also worried a little by the red Oil/water warning light and how quickly this followed my work on the coolant lines... checked all fluids, seem fine, though the coolant looks pretty grimy... dont know if thats normal.

[Booyah45828]

Red oil/water light is because there is no oil pressure with the engine not running.

I'd remove your batteries, charge them, and then have them tested, most auto parts stores will do it for free.

Grimy coolant isn't normal. You should probably flush it with a detergent based cleaner, and then install new. If the coolant has oil in it, you might need to replace the oil cooler o-rings and seals.