So I am having trouble determining which unit is the sending unit for my dash water temp gauge...
I am seeing two, almost identical sending units on the right side of the engine/Passenger side but MCI only shows one...
I know there is one for the engine compartment gauge, I will worry about that one later.
Is there a way to confirm what engine I have? I THINk its an 8v71...
(https://i.imgur.com/gCawYrd.jpg)
https://www.detroitdieselpartsdirect.com/documents/detroit-diesel-specs/detroit-diesel-model-number-high-res.jpg (https://www.detroitdieselpartsdirect.com/documents/detroit-diesel-specs/detroit-diesel-model-number-high-res.jpg)
https://www.detroitdieselpartsdirect.com/finding-your-detroit-diesel-engine-serial-number (https://www.detroitdieselpartsdirect.com/finding-your-detroit-diesel-engine-serial-number)
Key on, engine off...disconnect wire from sendi g unit, one at a time. Have someone watch dash for light or gage movement.
The auto shut down use its own sender or does it share?
Damned things...
Happy coaching!
Buswarrior
I have a 6v92 so it's different, but maybe this can help.
I was having mine shutdown at odd times. Turns out I had a loose wire on the temp sensing gauge that manages the shutdown.
For me that was the far right wire. If I grounded that wire it would shutdown.
Look on the face of the lower pulley it will be embossed there. Looks like an 8v71 but should say.
The water temps if like mine there is one on each side so you get an even reading and it is the one nearest to the rear doors. you might only have one on the passenger side.
This is as close as my short little arms can get but Detriot says it's not a valid number. I'm guessing it 8va192239...did they use paranthesis?
(https://i.imgur.com/Vopq390.jpg)
Should say 708x then the serial number the 7 stands for 71 series you are missing some numbers
You have an 8V71NA engine.
It appears from the photo you have a safety system tempstat in both sides, and a temperature guage sending unit on the right side. This is how it should be.
It also appears you have a mechanical temperature sender in the bottom of the right side. Maybe that's for the rear guage?
There should be two "senders" (one is a sender, the other is a switch) in the right hand thermostat housing, and one switch in the left hand thermostat housing. The switches on my MCI 8V-71 have red domes under the terminal, and an ohm-meter reads open to ground. They (Gumpy calls them Tempstats) switch and ground out the terminal when they get too hot. The sender has no dome, and should read around 150 ohms to ground.
Brian
Thanks guys. Detroit still cannot confirm my engine serial number so they cant get me parts. Or the parts guy was too lazy too try. Luckily MCI had everything I needed so far.
I replaced the BLUE Sending unit on the right side, ordered the Alarmstat for the left.
Here is the Right side, I replaced the far right top one today, no clue what the left one is yet. The bottom one is for the gauge in the engine bay.
(https://i.imgur.com/rCDZ6s5.jpg?1)
Here is the left side, the top is the Alarmstat and the bottom is....
(https://i.imgur.com/3kUJEGH.jpg)
Serial numbers are really not that important since those old engines have been changed and rebuilt over the years,that is a good serial number but not for a 1978 MCI that is a 1972 engine ,the 72 year model was from 164953 to 212755 the 1st 8v71 in 1973,your engine should have a serial number of 35xxxx or above if it was original in a 1978 MCI HTH
@gumpy
Any idea what the RED sensor is for? MCI doesnt list 2 of them and Detroit is useless.
Correction, the employee at the Detroit outlet you tried to deal with wasn't able to help a new guy looking for parts and answers...
Try a different dealer? One more likely to have an interest in 2 strokes? Marine, agricultural water pumps, the oil patch, still lots of 2 strokes in pockets...
Happy coaching!
Buswarrior
Quote from: PNWorBUST72 on April 05, 2018, 02:16:34 PM
@gumpy
Any idea what the RED sensor is for? MCI doesnt list 2 of them and Detroit is useless.
I believe that is your alarmstat switch. The left one in the photo of the right side with the red dome under the terminal. The right one in that photo is the guage sender unit, I believe.
The one in the left side head is also an alarmstat switch.
Call C&J Bus Repair in Bloomington, MN. They'll have those in stock. cjbusrepair.com
Quote from: bevans6 on April 04, 2018, 10:16:50 AM
There should be two "senders" (one is a sender, the other is a switch) in the right hand thermostat housing, and one switch in the left hand thermostat housing. The switches on my MCI 8V-71 have red domes under the terminal, and an ohm-meter reads open to ground. They (Gumpy calls them Tempstats) switch and ground out the terminal when they get too hot. The sender has no dome, and should read around 150 ohms to ground.
Brian
Brian wrote about the red domes above?
MCI told me yesterday that the red one is supposed to be an Alarmstat, one on each side. The part is the same as the one on the other side but it looks completely different then the one in that space now. I am not sure
Here is what the original one on the driver side looks like...
(https://i.imgur.com/7YnYegM.jpg)
The Maintenance Manual shows a very similar part on both sides too...
(https://i.imgur.com/xaMju2O.png)
Yeah, there should be one on each side.
You also need to figure out where the wire went to it.
And I'm wondering what that aftermarket sensor is with two wires going to it that looks like it's in the water pump outlet.
The one with two wires on the drivers side I am told is the fan controller, feed it power and both fans turn on. Not sure if thats a stock unit or process...
I got the "alarmstat" from MCI and it looks just like the red covered one...but now the one I pulled out and I thought was an alarmstat is much different so...what the hell is that 4in long "Cadillac" part I showed a pic of?
Always a struggle to do things right I guess...I will keep chuggin.
Thanks for your help all...
good possibility that the larger one is older and Kysor shrunk the package size at some time.
Quote from: PNWorBUST72 on April 12, 2018, 02:58:02 PM
The one with two wires on the drivers side I am told is the fan controller, feed it power and both fans turn on. Not sure if thats a stock unit or process...
What? Your bus has electric fans? Post some photos of that setup.
Quote
I got the "alarmstat" from MCI and it looks just like the red covered one...but now the one I pulled out and I thought was an alarmstat is much different so...what the hell is that 4in long "Cadillac" part I showed a pic of?
Probably aftermarket replacement. They typically are the same part. They're just a switch which turns on at a certain temperature and triggers the safety shutdown wiring system.