Ok so long story ... I thought the alternator was going bad on the truck ('98 12 valve) so I picked up a brand new one from napa. Went out to start the truck this morning and the batteries were dead .. ok so alternator is deffinitally shot. I threw the 6 amp charger on the truck and walked the mile to work. When I got home 12 hours later I swapped out the old alternator for the new one and tried to start the truck. The engine wouldnt turn over at all, all it did was click (not your typical batteries are dead and starter tries to engage click). Checked the batteries and they were partially charged .. should have been more than enough to turn over the engine. Tried the key again and noticed the 'wait to start' light didnt come on. Then I noticed the fuel gauge didnt read at all. Slowly all the gauge warning lights came on and the odometer slowly began to flash. What the heck did I fry with the slow charger/what the heck is going on???

 

I never charge a battery with the cables connected. I always isolate the battery. I would properly charge the batteries, install them then check the electrical system. Your partially charged batteries may be part of the problem.

 

Batteries are completely charged ... still get nothing but a click. Went through looking for any connections I may have knocked apart and cant find any.

I did use a screwdriver to arc the starter .. truck turns over strong so I still think there must be some else going on.

 

Sounds like starter solenoid issues.

 

The click you are hearing is probably the shutdown solenoid snapping up.
If you can start it by shorting across the starter it sounds like you have an ignition or blown fuse problem.

 

Thanks for the input guys. I've been reading threads trying to ideas for what could be wrong .. I've been reading threads all morning and this is the closest I've come to an identical situation: https://www.dieseltruckresource.com/...light=odometer

Aside from the tests on the wiring with a digital multi meter it looks like katmandu replaced his crankshaft position sensor and that solved his problems. While not a cheap fix at ~ $150 it couldnt hurt to replace the sensor. Any other ideas before I head to the parts store tonight?

 

Before you buy that CPS do a little troubleshooting. If you turn the key to start and the starter does not engage, check the starting circuit. If you have an automatic, run the shifter thru all the gears and try to start in park and neutral. It could be the neutral start switch. The manual trans. have a clutch switch.

If that does not help then check the starting circuit. You will need a volt meter and a helper. With the volt meter check the battery voltage and remember reading. Now get by the starter and attach the red meter lead to the solenoid terminal. Black to ground. Have helper try to start engine and check voltage reading. It should read battery voltage. If no voltage, the problem is in the start circuit.

If yes voltage, then the problem is in the starter/solenoid. Also check the battery terminal on the starter. It should read battery voltage. The fact that you arc'ed the starter would lead me to believe the problem is the start circuit.

If it is the start circuit there are a couple of more tests you can do.

 

Kbailey, did your tach quit working? If it did not, then your CPS is just fine.

 

You say the batteries are charged. Perhaps they have 12.6 volts now, but check them with a load. Maybe the voltage drops significantly, then your batteries are kapoot! They can appear OK with a volt meter, but not have enough voltage to start the engine.

 

Found that the 140 amp alternator fuse was blown .. replaced that but to no avail. The engine wont crank over with the key but it cranks when you arc between the solenoid and the started. Started to troubleshoot with a test light .. going to steal the multi meter from work tonight .. and found that I have no power at the light green wire with black stripe leading to the pcm discussed in the thread I linked earlier. Does anyone know what fuses supply power to that light green wire?

Also, still have no gauges at all and the "wait to start" light does not come on when the key is first turned to the run position.

 

98's are kind of a blend, some will have fuse #9 ( also make sure IOD fuse is good ) as the one that supplies voltage to the PCM, Infidel I think is the one that has found it elsewhere in later truck ( I am assuming ).

Also, when you find it, the truck should start, I would bet your starter relay is not dragging in the solenoid on the starter.

 

Check all your fuses in the power distribution center with the meter. Also, on my 96 I have a separate fuse panel on the drivers side, on the door side of the dash.

 

HUZZAH!! The truck lives again!!

After finally tracking down the location of the crank position sensor aka ESS I unplugged the sensor and the gauges came back to life. I turned the key and the fuel shutoff snapped up. Starter didnt crank so I crawled under and arced across the solenoid. Truck fired up and is now driveable .. woo hoo! Killed the engine and it started back up with the key so all is well .. just dont have a tachometer until I replace the cps.

Thanks to everyone who helped track down the problem!

 

You also do not have alternator charge or cruise, so get a new one before you drive it much.

 

Picked up the new sensor this morning and it is sitting in the passenger seat. Hopefully if I make it home by a reasonable time this evening it will go on tonight.