7520 preheater not working, EMERGENCY!

   / 7520 preheater not working, EMERGENCY! #1  

jrchafin

Silver Member
Joined
Apr 10, 2008
Messages
132
Tractor
Mahinda 7520
Hey folks,
My 7520 is 1.5 years old, and works great but has trouble starting cold. The light on the dash that looks like a heater coil only comes on for a few seconds when I turn the key to on position, then it goes out and the green healthy light comes on. I try to start and it chugs white smoke if the temp is below 30. Runs fine otherwise.
I believe the preheater is thermostatically controlled, and the coil light should come on and stay lit for 30 seconds or so, when it's cold out. So first question, how can I trouble shoot this?
More important question is how can I get this thing to start. We've got a foot of snow on the ground and my tractor won't start! :eek: Is there a way I can jump from the battery directly to the preheater and just manually do it? Or could I put some heating pads on the block or fuel pump to get it going? Advice??

Thanks!
 
   / 7520 preheater not working, EMERGENCY! #2  
Maybe your battery voltage is low??? Might want to hook it up to a charger or try hooking it up to a vehicle. Glow plugs draw a lot of current. If it is parked in your garage (like mine is :) ) you can put a heater and try to raise up the temp. How COLD is it? You might have other issues such as gel'ed fuel etc? Good luck and let us know what it turns out to be.
 
   / 7520 preheater not working, EMERGENCY!
  • Thread Starter
#3  
It's right at 30 degrees, not cold enough to gel anything. I've checked the manual and it says the heater coil light should be on for 35 seconds after putting the key to on position, and it's just not coming on. The engine cranks ok, so I don't think it's the battery, but I can certainly try jumping it.

Looking at the wiring diagram, it looks like it should be easy to jump from the battery to the heater element. Think I'll give that a try, but right now I have other stuff going on, so it'll be a bit before I give it a go.
 
   / 7520 preheater not working, EMERGENCY! #4  
It's right at 30 degrees, not cold enough to gel anything. I've checked the manual and it says the heater coil light should be on for 35 seconds after putting the key to on position, and it's just not coming on. The engine cranks ok, so I don't think it's the battery, but I can certainly try jumping it.

Looking at the wiring diagram, it looks like it should be easy to jump from the battery to the heater element. Think I'll give that a try, but right now I have other stuff going on, so it'll be a bit before I give it a go.
On my 4110 I turn my key left ( like I want to listen to radio in my car )for glow plugs , After the coil lite goes out on dash I turn key to right to start. If temp is in the 20's I cycle the glow plug twice. hope this helps
 
   / 7520 preheater not working, EMERGENCY! #5  
I don't use my 7520 much when it's cold but I am thinking that my "coil" light stays on long after the green "healthy" light comes on. Once I see the healthy light, I turn the key and it fires right up as long as it is not down in the low twenties or teens. Then it starts hard so I put a block heater on it.

I would put some halogen lights on it to get it warmed up. If you have at least one, aim it near the injection pump. Keep an eye on it so you don't melt anything rubber or plastic. Put a charger on the battery set on a low charge for an hour or so. Crank the amperage up when you go to start it.
 
   / 7520 preheater not working, EMERGENCY! #6  
First of all the 7520 doesn't have glow plugs, but they can be added as an option. The heater indicated on the instrument panel, is an intake heater which isn't as effective as glow plugs, but it helps.
At 30 degrees the 7520 should fire up without the heater, but if I were you I would install a block heater, which I think most of us dealers keep them in stock, at least I do. I have always installed the block heater at the point of sale, so I haven't had any complaints about starting. I will be in the shop tomorrow and will look in the service manual to see if I can find you any help.
 
   / 7520 preheater not working, EMERGENCY! #7  
There ya go! Seems like that is the ticket! (above)
 
   / 7520 preheater not working, EMERGENCY! #8  
There ya go! Seems like that is the ticket! (above)
You bet! Galen hooked me up. I used it once this year already. About two hours and I did not even need to preheat the intake.
 
   / 7520 preheater not working, EMERGENCY! #9  
The 7520 has a relay that energizes the intake manifold heater for about 45s after the ignition is turned on. Try this: Turn ignition on, raise hood and look at the intake manifold on the left side of the engine. There are wires [Ground&+] leading to it for the heater that is inside. After 30 s or so you should be able to feel some warmth on the outside of the manifold. Now try to start. It should fire right up. If no heat its probably the relay. You might try manually making the + connection temporarily for starting with a good clip lead [45 Amps] running straight from the + supply at the heater relay, then over to the + elec input stud on the heater. You should see a spark as you make the connection.
larry
 
   / 7520 preheater not working, EMERGENCY!
  • Thread Starter
#10  
Ok, preheater is definitely not working. I jumped from the positive battery terminal to the heater with a jumper cable, and after about 15 secs I could feel the warmth. Of course, before it wasn't getting warm at all. Also, the coil light on my dash was lit while I had the jumper in place. Correct me if I'm wrong, but that sounds like the relay to me.

It still chugged a little bit to start, but it started. I live in Virginia, and I'm not opposed to getting a block heater, but it seems like overkill. It just doesn't get that cold here. My dodge/cummins never has trouble. Do you think a block heater is necessary?

And next, the age old question, how much does it cost?? :D
 
 
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