It's getting hot.

     There's nothing like some good old fashioned summer heat!

     Frankly the heat here in Texas is not quite my idea of fun particularity after the wettest spring season the state has seen in a long time.  Suffice it to say I'm not a big fan of the humidity down here. The last few years Texas has been in a drought so it hasn't been so bad for me but this ol' mountain boy can feel it this year.

     The upside has been full lakes, with a little flooding, to play in.  The downside of the heat besides that its uncomfortable is that it's not playing nice with the bus.  When I drove the bus home from Missouri I noticed that when running it full open at 65 and climbing hills it would heat up a bit and since then it has been consistently show more symptoms.  Now that the summer heat is running 100 degrees its more prevalent.

     I have read as much as I can on overheating issues with the DT466 engine and talked with a number of service people and others along with using my knowledge to try and isolate the issue.  The general consensuses was to start with the clutch fan.  It was leaking a little fluid at the seal and never engaged at any temp.  Replaced it with a nice new $400 unit.  Ouch!  Unfortunately that has not resolved the issue. The new fan clutch does kick on but its very sporadic.  It seems that the air getting to the sensor coil on the front of the clutch is not consistent with the engine temp.  In fact when the bus gets to 210 degrees the fan won't come on unless I slow down below 35 mph then it will kick right in.  As soon as I get over 35 mph it goes off.

    I started temp testing the radiator, I have previously checked to see if it was dirty and clogged up on the outside preventing airflow, and the radiator temps were mid 180's on top and about 167-172 at the bottom about a 10 to 15 degree temp drop.  However I noticed that there was a cool spot that seemed to be about 145 degrees.  I figured that I'd better run it down and have the radiator guys check it out.

     I set up an appointment with Miller Radiator, the local radiator shop that a few people had mentioned.  I arrived early at 7:30 am to meet their top radiator tech.  He however had not arrived  as of 10:30 am and they were not sure when he would be in.  Someone else ran a pressure test and said it appeared good.  They suggested I look into the thermostat.  At this point I figured I'd run down to Southwest International and see what they would say.

     I  met with Bobby at Southwest International and gave him a quick rundown of the issues.  Based on that information he agreed that the next step was the thermostat.  I spent the rest of the day down at the shop while they got things arranged to have a tech replace the thermostat for me.  Something that I would normally do myself however I don't currently have anywhere I can drain out the coolant and do the work.  I didn't mind waiting as I had a vital door repair to work on and I had the radio project to keep me busy.

     While I waited for a service tech to become available I started looking in to that dang door. I couldn't imagine what caused it to go wacko like that all of a sudden.  So I started by testing all the air solenoids that operated the air cylinder and the all seemed to be in order.  Then I checked to make sure that the cylinder itself was operating properly when pressurized from each end.  That all looks good.  Which left two possibilities the air regulator and the electrical to run the solenoids.  I could already tell that the regulator has the signs of leaking and its possible that if it went bad that the higher pressure could cause the cylinder to stay in the extended position keeping the doors open.  The problem is that I don't really have a way to test the out put pressure to tell if its working or not.  So the electrical system would have to come first.  I tested the wiring coming to the solenoids and it wasn't making sense, I had the same voltages weather the switch was on or off, so I was assuming the issue was at the switch.  After I unscrewed the dash panel and puled it I had a good look at the back of the switch.  It all seemed to be in order with wires secured in each terminal.  I did a quick scan of the other wiring in the dash section and again thought to myself why is there so much wiring in here it seems half of it isn't even connected.  While I was scanning I saw a little wire that looked bright and fresh like it had just been disconnected and it didn't have the dusty aged look about it.  I examined further at the back of my door switch.  I pulled a little on each connection and looked closely to see if it possibly had pulled loose from on of the ports.  The very last port at the top of the switch had a bright clean spot where it obviously had another wire siting next to the wire still in the port and the terminal wasn't completely tight.  I secured the loose wire and made sure all the terminals were tight and check the door operation.  It was fixed.  Yahoo.  Thankfully no expense required and now I could move on to the radio.

     The tech got to me about 3 pm and got right to changing out the thermostat. Once he had it  replaced I chatted quick with the tech about if the issues did not resolve and he mentioned that the system looked good and that he would look at the radiator itself and the possibility of too much airflow over the clutch fan.  I packed up and headed out a couple hundred dollars lighter.