553 likely has a short and won't start

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Mimu

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Jul 11, 2010
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I am trying to remotely help my dad diagnose and fix a 2004 Bobcat 553 that appears to have a short and is now dead. I'm looking for any ideas and suggestions that I can forward on to him. I have never seen this machine myself. He's located far from any dealers, so calling someone else over is not a realistic option. He's going to have to fix this himself. One night last week he parked it and the next morning it wouldn't start. When he tried to start it, it momentarily made clicking noises (but the engine did not turn) and then immediately electrically shut down (dashboard and headlights stopped working). (thermal shut-off?) I'm not sure where the clicks came from (starter solenoid, starter relay, or something else). After a while (perhaps hours or overnight) the electricals would start working again. Sometimes (when he was doing something else, not trying to start it or fix it) he noticed that the headlights were suddenly on (without the key in the ignition). But if he tried to start it again, it again electrically shut down and stayed shut down until some random time later. Unfortunately he has not been able to even turn the lights on in the past few days (possibly due to repair attempts?). Prior to shutdown he thinks that he remembers all of the lights on the BICS being on solid. Even without the key in the ignition, the black ground cable connected to the battery gets warm and if left connected the battery discharges. When the battery runs low, he charges it. He now keeps the battery disconnected when not trying to fix it. We guessed that it might be the starter motor, but it works great when connected directly to the battery. The starter solenoid *appears* to be working also. He has also cleaned several of the electrical connectors. What other possible problem could it be, and how would one go about debuging and fixing this problem? I see people with other models reporting error codes here, but since this model has an analog hourmeter I don't think that we can get an error code. If there is a way to get any error codes (other than lights flashing on the BICS)?
 

Tazza

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So the battery is known to be good as you can start it with jumping the starter solenoid? +12v to the terminal should make the starter spring to life. If you hold the fuel shut off solenoid the engine should continue to run, does it do this?
 

mrfixitpaul

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Mar 28, 2009
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So the battery is known to be good as you can start it with jumping the starter solenoid? +12v to the terminal should make the starter spring to life. If you hold the fuel shut off solenoid the engine should continue to run, does it do this?
The only 'brain' in the 553 is for the bics. no other system that would give trouble codes. To try and locate the short, remove the fuses and disconnect the relays, put a test light inline with one of the battery cables and see if it lights....if yes, keep disconnecting things until it goes out.....if no, start connecting things until it comes on.....that should help pinpoint the problem area. Obviously you'll need to check the wiring harness for chafed or worn spots that could be shorting out, too
 
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Mimu

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Jul 11, 2010
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The only 'brain' in the 553 is for the bics. no other system that would give trouble codes. To try and locate the short, remove the fuses and disconnect the relays, put a test light inline with one of the battery cables and see if it lights....if yes, keep disconnecting things until it goes out.....if no, start connecting things until it comes on.....that should help pinpoint the problem area. Obviously you'll need to check the wiring harness for chafed or worn spots that could be shorting out, too
It's fixed! Thanks mrfixitpaul for your help! Your suggestions led us to finding the problem, even though the problem wasn't a short. I'm shocked that we didn't catch this sooner. I told my dad to do as you said - he started by putting a test light inline between the battery and the ground cable - only it didn't light up, indicating that there was no short. He tested further to determine that the ground battery cable wasn't even conducting - it turned out that it was badly manufactured. The plastic shielding was not stripped at the cable end - the battery clamp was connected directly over plastic shielding instead of to the bare copper of the cable. I guess that a small bit of the cable was touching the clamp until now, but finally burned up, corroded, or separated causing a fairly complete disconnect, and probably making it somehow warm up when there was any electical load (like the headlight switch being on) - fooling us into thinking that there was a short. The cable was fixed and then everything started working perfectly! -- On a separate note related to Tazza's comments: my dad partially pulled out the starter when he tested it by jumping it. I guess that testing it in place would have been easier and better. I think I read somewhere that some people just use a screwdriver to jump it? And when the time comes to one day do this (since this is new to me): what do you have to do to "hold the fuel shut off solenoid"? Thanks for the help!
 

Tazza

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Dec 7, 2004
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It's fixed! Thanks mrfixitpaul for your help! Your suggestions led us to finding the problem, even though the problem wasn't a short. I'm shocked that we didn't catch this sooner. I told my dad to do as you said - he started by putting a test light inline between the battery and the ground cable - only it didn't light up, indicating that there was no short. He tested further to determine that the ground battery cable wasn't even conducting - it turned out that it was badly manufactured. The plastic shielding was not stripped at the cable end - the battery clamp was connected directly over plastic shielding instead of to the bare copper of the cable. I guess that a small bit of the cable was touching the clamp until now, but finally burned up, corroded, or separated causing a fairly complete disconnect, and probably making it somehow warm up when there was any electical load (like the headlight switch being on) - fooling us into thinking that there was a short. The cable was fixed and then everything started working perfectly! -- On a separate note related to Tazza's comments: my dad partially pulled out the starter when he tested it by jumping it. I guess that testing it in place would have been easier and better. I think I read somewhere that some people just use a screwdriver to jump it? And when the time comes to one day do this (since this is new to me): what do you have to do to "hold the fuel shut off solenoid"? Thanks for the help!
A screwdriver would have worked to jump it too.
There is a fuel shut off solenoid that pulls an arm. If its not pulled back, the engine will not start as it turns the fuel off to the pump. Look for a cylinder with three wires attached near the injector pump, this is the solenoid.
If he tried to jump it with the starter in place, it would have narrowed it to a bad batery, starter motor or cable. I have seen issues with bad leads like this before. My dad has a crane on his truck, it stopped working, the terminal has corrosion causing it to simply click like you mentioned it did too. Something so simple can cause so many issues.
 

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