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hi i just bought a 6x4 diesel unknown to me someone by passed the auto thermostat for the radiator fan with a manual switch. (the switch didnt work when i tried it until i tore it apart and learned what it actually did) After running the unit on some hot days in PA it began to over heat, I thought it was a blown hose or leaking radiator but came to find out about the manual fan switch. Now when I run the gator both the red glow plug light and the amber light next to it both come on intermittently now when I run the machine for 5 or 10 minutes then they go out but will come back on again after awhile. The dealer over the phone thought I had a blown head gasket. Does this sound right to anyone, because I surely dont want to tear it apart for no reason at all. Thanks in advance Phil
 

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without a little more info you could have some issues that are easily fixed OR the head gasket theory "may" be right. It sounds like you're in the same boat I was last year, inherited at 97 6x4 diesel gator that I was close to giving away because I thought the repairs would be more than I was willing to spend. To shorten your quest for information, click on xcopterdoc, click his statistics tab and then click on his posts. There are over 100 but most are short and you can skip issues you don't need. When you see posts related to your issue, around page 3 for the radiator/core temp switches open them up to follow the string. Somewhere in there is good information on how to insure your radiator fluid is properly filled. You can also click on gatorvirgin and look up my posts but most of mine at that time was responding to xcopterdocs info. Lastly, go online to download the manual, it's about $10 for 260ish pages that cover both gas and diesel. Go online to find "signs" of a blown head gasket to prove or disprove the theory. Here's a copy of one post that may get you enough info to get you going
01-22-2014, 09:44 PM #2 xcopterdoc
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Join Date: Nov 2013
Location: NC
Posts: 122



The fan and light are 2 seperate systems.
The radiator core temp switch, when closed will complete the ground for the radiator fan. The hot wire to the fan is always hot and fan may run even with key switch off until rad core temps falls enough for switch to open. SOME LATER SERIAL NUMBERS USE A FAN RELAY. > 039741
The engine coolant switch, located at the thermostat housing, its only job is to tun on the coolant indicator light.
HOWEVER.. the coolant light also lights up when the glow plugs are on.
So it seems you have 2 different problems.
First the indicator light.. Does it ever go out? Even after running for more than 30 seconds? If it stays on, disconnect the orange/white wire at the engine temp switch. If it goes out, theres your problem. If it stays on for more than 30 seconds, chances are the glow plug timer module has gone bad. To check it, use a meter or test light and see if the glow plugs are staying on. If they stay on you have a bad module.
The fan running all the time is most likely the core switch. To check it, disconnect both black wires and using a meter, check to see if the switch is open (no continuity) or closed ( near 0 ohms ) If its closed, replace. If its open, then the ground wire to fan is grounded when it isnt supposed to be. UNLESS your serial number falls above 039741, then you may have a bad fan relay.
 

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Reply to both fixes on my gator

Before, when it was cool outside neither light went on at all, it was hard starting like a lot of them are even when you would leave the key on for 30 second intervals but eventually it would start. When it got hotter outside it started right up and neither light was on or would go on. On one ride around the farm it began to over heat and when it did both lights came on and stayed on until I got home on this first hot day run. After checking things out I did fill the radiator up and kept the coolant filled (it didnt leak but I didnt take a chance either) when I filled it up it took very little water, maybe a cup at most. After that time I found the hot wire switch that turned on the fan and ran that constantly (no more over heating) but this is when the two light began to come on and would go off periodically, when they come on it is for a short time then they stay on for a short time then go off. It appears they cycle maybe two minutes or less on then off for 5 minutes or so then they go on again. I cant detect any leakage in the head gasket area but the one time that it did overheat fluid was coming out somewhere around the radiator. At that time I thought I had a bad hose or leaking radiator but neither was the case it was I believe it was just that some Mo ron put that manual fan switch in place of the automatic one. Like it think I said in my original post with the seat cover in place I didnt know what that switch did initially (the wires were not making contact so who knew what it did). I really dont think I have a blown head gasket but short of tearing it apart its hard to tell one way or the other and based on the dealer who knows if they know or not either. Just odd that both lights come on like they are doing. Thanks for your help. Phil in Pittsburgh PA
 

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I was new to how a Diesel engine worked and I'll assume you may be too, so here are things to check; Diesels fire on compression of the fuel not a spark plug so its important to have a fully charged battery and clean electrical connections. Don't assume your battery cables are good because you cleaned the connections, any corrosive buildup within the cable will drop the cranking power to compress the fuel for a start. I've replaced my radiator temp switch and glow plug relay just to find out they were working but had poor connections due to corrosive/dirt build up on the connectors. You said it's hard to start in the cold but starts better when the weather is warm, my "guess" would be the glow plug relay may be the first thing to check but read the post I attached from xcopterdoc again. It pretty much covers your possible problem. As for a head gasket leaking, check for coolant/foaming in your oil. One more thing, any air in the cooling system may cause low or improper flow of the coolant. xcopterdoc told me to place a broom stick under the hose by the fill cap to insure it's higher than the engine/radiator. this will allow all the air to purge.
 
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