Hi all....I am kind of stumped here. The truck won't start, it just cranks and cranks. The only way to get it to start and run is to manually energize the heater grid (via a battery charger hooked to both pos. leads at the grid, during cranking). We got the truck started and noticed that the tach doesn’t work & alternator won’t put out voltage/charge. From what I have read is that no tach/alt is the crankshaft pos. sensor. I also hear that the alt. not charging could be the PCM and I am wondering if that would this also cause the tach to not function? I was about to do the external volt. reg. but when I noticed that the tach didn’t work…..I though about the crank sensor. Would a bad crankshaft position sensor cause the hard/no start issue?

The other thing that has me puzzled is that the truck ONLY starts up with the heater grid being energized…..it’s 90 degrees outside…..I thought the grid didn’t come on unless it was 66 degrees or colder?

My plan now is to get the batteries charged fully, start it up….drive over to my local auto parts store and have them pull the CEL codes. Guys….any help would be greatly appreciated….

Thank you

Derek

Also....the lift and inj. pump were changed out about 1 1/2 years ago..with no issues untill now.

 

If the crank position sensor is not working, the ECM won't know the truck is running (or trying to) and thus won't engage the alternator or energize the fuel pump. Retrieving codes would be most helpful. I have heard that a faulty crank position sensor or Cam position sensor will cause no start issues. I am surprised however that you were able to start the truck by energizing the grid heaters; this is very strange to me. Might want to check and clean your grounds as a precaution. Good luck!

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BTW,

 

i would put money on its ur crank sensor behind the starter. if the crank sensor is out on a 98.5-00 then the altenator wont charge, and 01 and 02 its the cam sensor that controls the alt. good luck with gettin it fixed

 

Thanks guys,

Ok...today I installed an external voltage regulator so I can drive the truck down to the autoparts store and get the codes checked. Now the stupid tach is working. I will take it out for a spin and see what happends. I'll keep you guys posted.