My ac compressor and engine won't shut off riddle. Anybody solve it?

MN170

Member
2007 Freightliner Sprinter.

Here is the timeline of events that is currently happening:

New AC compressor installed. Worked great.

Two weeks later on the beginning of our trip through South Dakota, the AC will not turn off. You can press the button to turn it off, but it will continue to blow cold for hours.

Later this same day after climbing elevation, the RPM"s at 70mph were constantly at 3700. Seemed really high. We pulled off to get diesel and the van wouldn't shut off and the coolant must have been getting too hot because the coolant started to overflow and drip from above the ac compressor.
I had to pull fuse #16 next to the obd2 port to get the engine to shut off.

After hours of trying to figure out what was going on, I unplugged the ac compressor wiring clip, so it wouldn't get power.

Since doing that everything has been back to normal except the engine still won't turn off and I have to remove fuse 16 to get the engine to shut off. It will not restart unless I unplug the negative battery connection by the accelerator. Only then will the engine start.

Any ideas what the hell is happening?
 
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4wheeldog

2018 144" Tall Revel
I would examine the wiring harness near the exhaust system. Since it was hot, any exhaust leakage could toast the harness.
Anytime multiple electrical problems show up together, a harness problem is a definite possibility.
 

showkey

Well-known member
Sprinter wont shut off..........Power back feeding is the cause,

Others have reported Root cause as........ climate control panel shorted or failed, tail light assembly shorted or corrode, brake pedal switch failure, bad ground various locations, ABS/EPS issue back feed ( brake systems error lights on) , trailer wiring issues. After market backup cam issues.

Since yours is AC related .......climate control Panel would be a prime suspect. Is that AC compressor a MB part or aftermarket part ?? Coolant over flow ......engine over heating fans not working ? All could be Related to AC system and compressor and climate control panel failure.
 
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autostaretx

Erratic Member
In the T1N simply mis-inserting the license plate light bulb could cause failure-to-stop engine issues.
I don't *recall* hearing similar in the NCV3, but that's just my memory.

I fully agree with 4wheeldog and showkey about inspecting the wiring (also look for rodent chewing damage anywhere on the under-van harness)

--dick
 

elemental

Wherever you go, there you are.
In the T1N simply mis-inserting the license plate light bulb could cause failure-to-stop engine issues.
And the engineers who crafted it would probably say "No matter; if you maintain the vehicle properly this won't be a problem." The idea of avoiding failures through design rather than maintenance appears rather lost on some people, including German automotive engineers. The Japanese automotive engineers appear to heartily accept the concept, though.
 

220817a

Independent & Self Reliant - From Chattanooga TN
2007 Freightliner Sprinter.

Here is the timeline of events that is currently happening:

New AC compressor installed. Worked great.

Two weeks later on the beginning of our trip through South Dakota, the AC will not turn off. You can press the button to turn it off, but it will continue to blow cold for hours.

Later this same day after climbing elevation, the RPM"s at 70mph were constantly at 3700. Seemed really high. We pulled off to get diesel and the van wouldn't shut off and the coolant must have been getting too hot because the coolant started to overflow and drip from above the ac compressor.
I had to pull fuse #16 next to the obd2 port to get the engine to shut off.

After hours of trying to figure out what was going on, I unplugged the ac compressor wiring clip, so it wouldn't get power.

Since doing that everything has been back to normal except the engine still won't turn off and I have to remove fuse 16 to get the engine to shut off. It will not restart unless I unplug the negative battery connection by the accelerator. Only then will the engine start.

Any ideas what the hell is happening?
I had a condition similar to yours happening on a 2008 Dodge Sprinter where the engine would not turn off by switching off the ignition. In my case the culprit was the GPS tracker that the finance company installed prior me getting the van from the dealer that sold the van to me. After I completly removed the GPS tracker that was connected directly to the ignition switch and cleared all the EZS fault codes, never had a problem again.

You need to look at the EZS fault codes to see understand what's triggering the condition.
 

MN170

Member
Sprinter wont shut off..........Power back feeding is the cause,

Others have reported Root cause as........ climate control panel shorted or failed, tail light assembly shorted or corrode, brake pedal switch failure, bad ground various locations, ABS/EPS issue back feed ( brake systems error lights on) , trailer wiring issues. After market backup cam issues.

Since yours is AC related .......climate control Panel would be a prime suspect. Is that AC compressor a MB part or aftermarket part ?? Coolant over flow ......engine over heating fans not working ? All could be Related to AC system and compressor and climate control panel failure.

The ac compressor doesn't look to be oem:
20200717_173352.jpg
 

MN170

Member
Well, the verdict is in.

That issue with the engine not shutting off when key is removed: Relay k7 was bad and the 10pin connector had corrosion from water ingress. We found a missing grommet in the firewall that may have been the culprit.

The slight over heating of the engine with the brand new AC compressor turned on and running: The water pump was starting to go. Got that fixed and all is well.

I guess it was coincidence that these two issues came on at the same time...?
 

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