Wait till it gets warmer.

 

I've heard keep it plugged in below 40, and you might try spraying wd-40 in the intake.

 

make sure your air intake temp sensor is working/functional. if that is bad, the grid heaters won't cycle at all and you'll be cranking for days. Be sure you have a really good battery, make sure your grid heater relays are working and make sure your grid heater elements aren't burned out.

 

No WD-40, No brake parts cleaner, No ether.

You shouldn't have to keep it plugged in to make it start if your grid heaters are functioning AT ALL.

 

At 37* it should start without grid heaters, you should hear a click coming from your left fender well when you turn your key on. If not either ECM, wiring, Air intake sensor, or solenoid problem. You can operate the solenoids with a push button to get you by until you find your problem. The small wires on the front sides of the solenoids are ECM ground make them body ground, the other small wires on the back side are ECM hot, make them hot with a push button switch.

 

Start with the wire on the fuel shut off solenoid, and work from there.

 

I agree. It should start at 40* without the grid heater. Did you try to start it before you unplugged the temperature sensor?

There is nothing wrong with determining if the heaters and heater-relays are working...but, I'd guess you have an intermittent fuel-shut-off-solenoid problem.

 

I agree I don't have my grids in and it was 28 this morning fired like it was 80 out

 

I've never had a wait to start light on or anything like that? It's an 89 would it even have a grid heater or anything like that


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it would have the heaters, there is something wrong with them. i'll let someone who knows more than i do comment. i'm not familiar with the heaters

 

The grid heater is located between the air intake horn and the intake manifold, there will be some heavy wires on the front and back of a block between them the wires go to 2 solenoids mounted on the left fender well and the heavy black wires are fastened to the tops of them. I'm not that familiar with a 89 I know there are a few differences.

 

:ditto: my 89 was just like this, two relays two wires to the grid, two wires from the battery.

 

Thanks fellas, I had my girl plug it in so I can just jump it when I get home from work so I can get it out of the wind and into tue garage to start tearin into it


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Ok update, she forgot to plug it in and it barely made it over 40 today, I unplugged a two wire sensor under the intake horn and she fired right up no problem, what's with that


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when you unplug the sensor the truck thinks it is cold outside and will force the grid heaters to cycle regardless of the air charge temp. If it fired right up after you unplugged it and it fired right up, that sensor is likely damaged.

 

Well why can't I just leave it unplugged then??


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it'll run in the summer for the full cycle even after the truck is running which can lead to overheating and burning out of the element, which kinda sucks, but they are readily available on the forum used... .so I'd run that b!tch for how long that truck is probably going to last you it'll be fine.

 

Wait, if I un plug the sensor and the grid heaters are forced to work but when it's cold out and I have the sensor hooked up and the truck won't start, wouldn't the grid heater circuit be broke instead of the sensor??


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Ha, retract that last one, I'm thinking like a dip at the moment!!!


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Whew, for a second there I thought you were demonstrating why the truck wasn't going to last long.

Thankfully, Cummins engines are tough enough to survive our moments of insanity most of the time.

Now I ask the experts, is the temp switch open when cold, and closed when it reaches temp (59° I believe)?