Onan 4000 Code 38

[Selmahotrod]

My Onan 4000 runs great until I turn on A/C. After about 3 minites of running it shuts off and gives code 38. That is an overload code and the AC is all I got on. I dont know where to start. Any ideas?

 

[macdaddy1111]

You check oil level?

 

[Selmahotrod]

Yes, I made sure it was not overfilled. It is on the center off stick. I just bought the motor home so I dont know the history of any problems.

 

[macdaddy1111]

Yes, I made sure it was not overfilled. It is on the center off stick. I just bought the motor home so I dont know the history of any

Plenty of gas in tank?

When last time filters and plug change?

Have u tried something besides AC that doesn't draw as much load as AC?

 

[16ACE27]

Code 38 is overcurrent. Have you checked your output voltage and frequency since it had the head gasket replaced? Being low on either will cause the A/C to draw too much current. And there is more than the A/C running, The converter/charger is always running when 120 VAC is available. Did you check the electric switch on your water heater?

 

[Selmahotrod]

Heater is off. Have not checked voltage or fequency since I dont know how.

 

[Selmahotrod]

How do you adjust voltage and frequency?

 

[Selmahotrod]

Plenty of gas in tank?

When last time filters and plug change?

Have u tried something besides AC that doesn't draw as much load as AC?

Everything elese works good.

 

[Chateau_Nomad]

The dipstick on my Onan 4k generator is notoriously inaccurate. I forget the specified oil quantity, but I carefully measured mine a couple times... both in an out. Going by the book, full on mine with motorhome perfectly level is just touching the edge of the fill tube... right at overflowing. I think measuring the oil is far more accurate.

Regardless, I don't really think that's your issue... you could have an excess resistance problem (loose corroded cables) or something else related.

 

[PreCambrian]

Check voltage and frequency as suggested previously. Check voltage both at the generator and the AC. Then measure the current output by the generator and also used by the AC. This will determine if you have an actual overcurrent or it is the generator sensor.

I always carry a clamp on AC/DC current meter (Amprobe) because it is very useful in troubleshooting. I also carry a Fluke multimeter. Saves a lot of guesswork.

 

[Beau388]

How do you adjust voltage and frequency?

Frequency is adjusted by engine RPM (there a screw on the linkage). Voltage is not adjustable on a J spec 4000 generator. If it is a H spec, it is adjustable (see the operator manual)