753 Not cranking...electrical issue?

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ddlaz

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Joined
May 14, 2014
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Hi all, I've got a 90's 753 that is refusing to turn over today. I've read of some good help on here so I thought I'd join and ask my own question(s). This bobcat has never given me any issues, I usually just jump in, turn the key, crank for a couple secs and it's going. First question, when I turn the key to run, I hear a solenoid click -- glow plugs? Second, there are two red lights near the key -- one has a picture of a light bulb i'm guessing is the glow plug circuit, the other is a gear with a drop inside. Both the lights stay lit when the key is in the run position. Is it supposed to? Does it mean that the glow plugs are on? It was my understanding that the glow plugs only came on when I held down the pre-heat button. I ask these questions first because for some reason, I decided to try the pre-heat button and see if it would crank in 1 second instead of 2. Stupid of me. According to the diagram/table, I should preheat for 10 seconds at 50-70*(or something like that). I turned the key to run and held the preheat button for 10 seconds. Then I tried to start. All I heard was the click of the starter solenoid. I visually verified that it was the starter solenoid kicking the gear out. The problem is that it doesn't engage or crank over at all. I checked battery voltage and it was 12.6, but I checked it when I took it out of storage last month and it was 12.6 as well so I don't think battery voltage is an issue. I've got it on a charger right now just in case. One thing to note is that the two red lights come on slowly when I turn the key to the run position. It's dim at first then brightens up, meanwhile the battery voltage gauge slowly increases until the red lights brighten up. All this leads me to believe that the glow plugs are stuck 'on' and draining power from the battery, even while cranking. How can I test this or disable the glow plugs? If any extra info is needed to help understand my problem, feel free to ask. Not sure of the engine make, it doesn't say kubota or otherwise anywhere that I can see. Thanks in advance for your help!
 
Cheak you battery fluid and connections
Had auto one test the battery and it's good. Posts are clean and so are the wires. I had just used it the day before without issues until I decided to try the same preheat function.
 
Had auto one test the battery and it's good. Posts are clean and so are the wires. I had just used it the day before without issues until I decided to try the same preheat function.
Did you check the fluid in the battery
 
Had auto one test the battery and it's good. Posts are clean and so are the wires. I had just used it the day before without issues until I decided to try the same preheat function.
Yes. It was full so I brought it to autozone after charging last night.
 
Turn the key on then jump the big wire to the little wire on the starter and see if it cranks be careful you will jump lol
I was going to try that next. Anyone have an idea on disabling/disconnecting the glow plug circuit ? Is it as simple as disconnecting the wires from the glow plugs? I want to see if it stops the current draw.
 
I was going to try that next. Anyone have an idea on disabling/disconnecting the glow plug circuit ? Is it as simple as disconnecting the wires from the glow plugs? I want to see if it stops the current draw.
Yes but I would take it off the lead side of the solinoid in case it is sticking some where
 
You could unplug the glow plug relay to disable the glow plugs, but I don't think that is your problem. If the glow plugs relay was stuck on, it would drain your battery. You could remove a battery cable from the battery and then lightly touch the cable to the battery terminal and watch for a small spark, or use a test light from the cable to the terminal. I may be your starter, give it a tap with a hammer and see if it starts. Bill B
 
You could unplug the glow plug relay to disable the glow plugs, but I don't think that is your problem. If the glow plugs relay was stuck on, it would drain your battery. You could remove a battery cable from the battery and then lightly touch the cable to the battery terminal and watch for a small spark, or use a test light from the cable to the terminal. I may be your starter, give it a tap with a hammer and see if it starts. Bill B
I didn't take a hammer to it, but I did give it a few kicks. No difference. When I first thought it was the battery, I tried to jump start it from my truck. It cranked over a couple times which made me think it was the battery so I had it tested. Unfortunately the test came back positive. I checked voltage drops between the terminals and their respective cables, and from the cable to the starter. All checked out which lead me to believe it was the glow plugs pulling juice away from the starter...as farfetched as it is.
 
I didn't take a hammer to it, but I did give it a few kicks. No difference. When I first thought it was the battery, I tried to jump start it from my truck. It cranked over a couple times which made me think it was the battery so I had it tested. Unfortunately the test came back positive. I checked voltage drops between the terminals and their respective cables, and from the cable to the starter. All checked out which lead me to believe it was the glow plugs pulling juice away from the starter...as farfetched as it is.
Did it crank jumping the solinoid?........and I don't trust kids at part stores it could just be you battery
 
Did it crank jumping the solinoid?........and I don't trust kids at part stores it could just be you battery
While your in there make sure your connections are good on the starter and the mounting bolts are tight I have seen a loose starter not groud good enough also check your grounds
 
Did it crank jumping the solinoid?........and I don't trust kids at part stores it could just be you battery
Have not tried that yet Ant. I'll try when I get home tonight. I'm going to hook up my truck battery and see if it makes a difference, although jumping it should have helped.
 
Have not tried that yet Ant. I'll try when I get home tonight. I'm going to hook up my truck battery and see if it makes a difference, although jumping it should have helped.
Wish you luck hope it is cheap and easy
 
cheap and easy rarely occur in the same sentence when it comes to a solution.
Make sure you check the ground cable and connections as well. Just had that issue on mine. Had to replace the ground cable.
 
Make sure you check the ground cable and connections as well. Just had that issue on mine. Had to replace the ground cable.
sounds like the starter. definitely try hitting it with a hammer while someone turns the key. kicking it will not do the same thing
 
sounds like the starter. definitely try hitting it with a hammer while someone turns the key. kicking it will not do the same thing
I find the easiest way to work it out is to use a screw driver or pliers to jump from the small wire to the starter to +ve, if it spins, the problem is further back to the key. If it doesn't spin, it's the battery, battery cable or the starter its self.
If it cranks, but slowly, carefully feel around for hot spots, hot spots are areas of high resistance. My S250 had a slow crack, i found a bad connection to the starter, cleaned it and it works much better.
 
I find the easiest way to work it out is to use a screw driver or pliers to jump from the small wire to the starter to +ve, if it spins, the problem is further back to the key. If it doesn't spin, it's the battery, battery cable or the starter its self.
If it cranks, but slowly, carefully feel around for hot spots, hot spots are areas of high resistance. My S250 had a slow crack, i found a bad connection to the starter, cleaned it and it works much better.
Fixed it last night. Jumping it didn't work, it was the same slow whirring. On a whim, I checked the fuse boxes that seemed to just be hanging there. A lot of cloudy water came gushing out as I opened the fuse boxes. All the fuses had light corrosion deposits on them but one of the fuses blades were flimsy and seemed to have rusted away. I cleaned up the box and replaced fuses. Starts right up as usual! Thanks for all your help everyone. On to the next problem....
 
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