400 ISL - Faulty Intake Manifold Temperature Sensor?

[96 EVO]

This morning with cloudy skies, the outside temp is reading bang on, and within 0.2F of basement temp.

It's definitely mounted somewhere that retains heat from the sun! 

[DennisZ]

I did some digging for the diode P/N that I used for the replacement, best I can figure, it’s a 1N4148, about $3.00 for a lifetime supply on Ebay.

[Bill R]

Repaired and Success!!

First the Aladdin Outside Air Temp Sensor.  If it were the proverbial snake, I would have been bitten.  The sensor was hanging in the propane tank bay on the wire harness for the propane tank level indicator, passenger side.  See pic below.  When I went to inspect it, the two wires came out of the thermocouple bi metal tip.  I reinserted. crimped a bit, and taped.  Getting a good reading now.

Second, I bought a new Intake Air Manifold Temp Sensor.  Installed, started engine and got a good reading.  Took the coach for a spin and the temp stayed steady at around 30F above outside temp.  See pic below.  So I am very satisfied with these results.  An interesting adder to this, while I was researching the Intake Temp Sensor, I decided to look at recently downloaded Insight ECM data.  (Thanks to @Frank McElroy for formatting for me)  What I discovered was that the reading was normal at the time of the download, but there was a history of 5 High Intake Temp faults from this sensor over the past 200 engine hours.  Each fault only lasted for 1 second.  I guess the Intake temp Sensor finally gave out.  

Thank you to all who commented on this post.

 

[Frank McElroy]

1 hour ago, Bill R said:

Repaired and Success!!

First the Aladdin Outside Air Temp Sensor.  If it were the proverbial snake, I would have been bitten.  The sensor was hanging in the propane tank bay on the wire harness for the propane tank level indicator, passenger side.  See pic below.  When I went to inspect it, the two wires came out of the thermocouple bi metal tip.  I reinserted. crimped a bit, and taped.  Getting a good reading now.

Second, I bought a new Intake Air Manifold Temp Sensor.  Installed, started engine and got a good reading.  Took the coach for a spin and the temp stayed steady at around 30F above outside temp.  See pic below.  So I am very satisfied with these results.  An interesting adder to this, while I was researching the Intake Temp Sensor, I decided to look at recently downloaded Insight ECM data.  (Thanks to @Frank McElroy for formatting for me)  What I discovered was that the reading was normal at the time of the download, but there was a history of 5 High Intake Temp faults from this sensor over the past 200 engine hours.  Each fault only lasted for 1 second.  I guess the Intake temp Sensor finally gave out.  

Thank you to all who commented on this post.

 

Thanks for posting this update.  I'm sure it will help others in solving similar issues.

[96 EVO]

I know I'm going to have a better look in there!

I have a wire harness coil that looks a lot like that!

[welleking]

I fear a temperature sensor in my system is screwed up. My 06 windsor is new to me but suspect that the previous owners may have been on this site too. Anyway the scan guage shows a voltage reading light the grid heaters are cycling while driving down the road.  This would drive the alternator and its installed regulator nuts..the aladdin jr is showing an almost constant 13.5 to 13.7.. neither is high enough to suit this retired electrician/ mechanic. 

Any help or input welcomed.

Wayne E 06windsor 

[Bill R]

@welleking What is your Aladdin Jr showing as your intake manifold temp when this happens?  This reading is coming straight from the ECM input of the temp sensor.  So if it is faulty reading low causing your grid heater to come on then that would show on the Aladdin Jr.  When my intake temp sensor failed is was showing high temp.

 

[welleking]

I am just learning the system in this new to me coach. right now I am more worried why my genset starts while I am driving.. It happened twice this morning. The first  time I questioned my memory, the second I was sure.

 

WAYNE E

[Bill R]

@welleking Sounds like your AGS (automatic generator start) is engaging.  I have attached the manual for the Magnum AGS.  Read through it and on page 12 it goes through how to turn the AGS off.  This is the unit I have on my '06 Windsor.  If you need more help, feel free to PM with your phone number.

Magnum ME AGS Operator's Manual.pdf

[Tom Cherry]

14 hours ago, Bill R said:

@welleking Sounds like your AGS (automatic generator start) is engaging.  I have attached the manual for the Magnum AGS.  Read through it and on page 12 it goes through how to turn the AGS off.  This is the unit I have on my '06 Windsor.  If you need more help, feel free to PM with your phone number.

Magnum ME AGS Operator's Manual.pdf 274.55 kB · 1 download

I doubt (memory?) that the OEM Inverter was a Magnum.  NOW, if he has a replacement...it MAY be a Magnum.  OTHERWISE...maybe the Heart/Trace/Xantrex/Freedom variety.  @welleking...  If you get the PN or the Model or the brand, and it is NOT Magnum, use the search box at the top right.

Put in Heart or Trace or Xantrex or Freedom and then click on the EVERYWHERE for a Drop Down.  Click on FILES.  That is where all the "Manuals and Drawings" are located.  I did if to verify....here are the LINKS for each key word....I also found a few more references. 

NOW....IF your Genny is STARTING....and you DO have an Automatic Generator Start (AGS) and it is ENABLED....then there is only ONE reason.  ASSUMING it is set for LOW VOLTAGE....you have lost or are loosing your House Bank.  When they become discharged, and in your model and year, there was no "AUTOMATIC" way to charge them as you drove....then you need to "check that".

NOW, if you do NOT have the AGS or it is not "ENABLED", you have a "short" as in a wire that is hitting the CHASSIS.  MOST of the Onan Generators that Monaco installed (more recent...YES....older...Probably), use a NEGATIVE START SIGNAL.  So, if one of the wires in the harness from the dash or any OTHER Generator Start Switch location is chafed or nicked or has lost the insulation....and that eventually touches the metal of the chassis....BINGO....that tells the Genny to start...  Just like pushing the button.

 

 

https://www.monacoers.org/search/?&q=trace&type=downloads_file&quick=1&search_and_or=and&sortby=relevancy

 

[Bill R]

@Tom Cherry His issue is with his "new to him" '06 Windsor.  His signature is not updated with the Windsor.

[Tom Cherry]

6 hours ago, Bill R said:

@Tom Cherry His issue is with his "new to him" '06 Windsor.  His signature is not updated with the Windsor.

Thanks for the “FIND”.  It is VERY Confusing and leads to faulty or incorrect recommendations.  I took his signature as correct.  I have edited his profile for clarity as well as revising his profile signature.

@welleking.  If you want to revise anything, then click on your “icon”.  That takes you to your Info & Profile screen.  Then click on edit or my profile.  Fix as needed….this is very important…..obviously….  

Second “housekeeping” item.  Please do NOT use a post pertaining or related to “Apples” and then wander off and start asking questions about “Oranges”.  That creates a problem for the users or members and the moderating site.  The proper process is to start a new topic.  BUT SEARCH FIRST.  Then if nothing has been posted, start a new topic…...maybe titled…. “Generator starts mysteriously….new owner….suggestions?”.  Then state the issue.  As it is, the AGS issue (hopefully) cannot be searched so that folks having the same issue can learn and NOT post s new topic.  We are trying to keep the site organized.  We all learn.  Thanks in advance for following the instructions for staying focused or on the same issue and also posting in the future.

Thanks.

[welleking]

The AGS was my thought exactly, but the why has me perplexed. 

My inverter is indeed a magnum and the low volt start is set at 11 volts. The voltage reading there was 12.5 when I started the generator and turned on the block heat. An hour or near that I shut off the block heat after starting the engine the alternator light flashed and i shut down the generator..I  THINK. I stopped at a rest area 70 miles later and it was running. shut it off for sure this time drove another 2 hrs and it was running. At this time I had the POs by pass switch was open. This was built 6 years after I tried to retire from RV repair and I had never heard about  VADIL  nor ALADDIN. I installed HEART  units and had 2 in my executive. The major question in my mind is what could be using the power at that rate.. I can believe my big boy combiner IS BAD. That will change soon. should I add an ammeter shunt to help find the problem since I can only read my clamp on really close....

WAYNE K 06 WINDSOR

[welleking]

I think I have found the reason for the generator starting when I don't think it should... after running an AC refer for so many years I had forgotten to check its MODE  and it was using nearly 400 watts almost constantly.  22 years ago I was warning RVers about exactly this.