255 electrical issue

[jmh1783]

Hi,
I went out yesterday to start my tractor and nothing. It clicked but wouldn't turn over. I charged the battery. The charger said it was 70%. When I turned the key to on, I hear this ticking from under the hood. I narrowed it down to one of the relays and pulled it. The ticking stopped. Looking at the service manuel it is labled "glow plug heater". I know, it doesn't have glow plugs. Right next to it is another relay for the inlet air heater. Not sure why two relays. The dealer is saying at least 5 weeks backlog. I need to try to diagnose this myself. Any help would be appreciated.

I was getting a check engine light. The two codes I'm getting are P1611 communcation error and P1804 ground control relay. These descriptions come from a generic OBD reader so no idea if they are accurate. I had a problem like this later winter. I think water got in somewhere. It is sitting outside again so I'm wondering if I have a short. Any idea where to look? Thanks for any suggestions.

John

 

[TractorNH]

Even though it doesn't have glow plugs everything still refers to them. Everthing related to glow plugs is really for the intake manifold heater. That doesn't really help diagnose your problem though....

 

[R134a]

This is a "no crank" condition so start simple. You need 12V + the amperage to spin the starter. Pop the battery caps and verify the electrolyte levels are correct. Make sure your terminals are CLEAN. Good batt should be 12.6V seen on a DVM. Battery has to be tested under load. Battery could have lost its capacity which means a trip to the parts store. *Codes are set when the motor is running. Forget the OBD stuff for now. Scanner is likely wrong as it doesn't have the HD protocol. Voltage spikes can be hazardous to the computer's health so I would avoid jumping it.

 

[jmh1783]

This is a "no crank" condition so start simple. You need 12V + the amperage to spin the starter. Pop the battery caps and verify the electrolyte levels are correct. Make sure your terminals are CLEAN. Good batt should be 12.6V seen on a DVM. Battery has to be tested under load. Battery could have lost its capacity which means a trip to the parts store. *Codes are set when the motor is running. Forget the OBD stuff for now. Scanner is likely wrong as it doesn't have the HD protocol. Voltage spikes can be hazardous to the computer's health so I would avoid jumping it.

The battery is the sealed type. Terminals are clean and tight. I'm getting weird noises in the ON position. A rapid ticking from the console area and of course the slow clicking from the relay I mentioned. I do get a tick when I turn the key to start but nothing happens. Any way to test without buying a new battery?

 

[R134a]

Sounds are your friend. Now do you have that digital voltmeter ? AutoZone might lend you a load tester but you could do some tests w/ the digital meter. & I wouldn't bet my life on a maintenance-free battery. Put the battery in the tractor and keep the meter hooked up right on the battery. With everything off, do you see 12.6 V or close to it ? Turn the headlights on. See a small voltage drop. Turn em off, voltage should quickly bounce back . Watch the meter and have somebody hit start. Does the voltage now take a nosedive? Does it bounce back near 12.6V when you let off the key? I bet it never makes it past 10.4V.... (dead cell). Also remember the glow heater wants to come on when you start. That drains amperage too. The relays chatter from insufficient power. This is a guess as I can't see anything from here buy my money says your battery is toast.

 

[jmh1783]

Sounds are your friend. Now do you have that digital voltmeter ? AutoZone might lend you a load tester but you could do some tests w/ the digital meter. & I wouldn't bet my life on a maintenance-free battery. Put the battery in the tractor and keep the meter hooked up right on the battery. With everything off, do you see 12.6 V or close to it ? Turn the headlights on. See a small voltage drop. Turn em off, voltage should quickly bounce back . Watch the meter and have somebody hit start. Does the voltage now take a nosedive? Does it bounce back near 12.6V when you let off the key? I bet it never makes it past 10.4V.... (dead cell). Also remember the glow heater wants to come on when you start. That drains amperage too. The relays chatter from insufficient power. This is a guess as I can't see anything from here buy my money says your battery is toast.

You are correct. I'm an idiot. I guess the design confused me. I added water to the cells and put it back on the charger. I'll bet I killed it though. I do have a digital meter. I'll try those tests. Anyone know what size battery to buy? The manual just says 12v 100ah. I think I need size, right? It's hard to see the top to get a look at the group size.

 

[Dave M7040]

You need to be looking for a part of a battery spec: CA or CCA.
Cranking amps or cold cranking amps.

Batteries of the same physical size can have substantially different CCA numbers.
Buy the one with the highest CCA which physically fits. Yes it will cost more but it will give you much better service.

Modern tractors with some electronics have to incorporate diodes around relays to protect the electronics.
Boosting and using a charger is an opportunity to momentarily mis-connect the cables and short the diode(s) leaving you with big trouble shooting issues.

John Deere is using so many diodes they are incorporating them into a block like a relay.

Simpler designs use this style

I am not suggesting you have diode issues now but rather trying to caution you on the risks of nursing along a battery which should be replaced.

Dave M7040

 

[R134a]

Dave is absolutely right. I replaced one on my Scag mower last month. Saw it on the schematic as it was hidden under the control panel. Don't panic as we're not there yet. Leave that for plan B.

 

[R134a]

Fixed ???