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Discussion Starter · #1 ·
Hi folks:
My '96 with the E4OD tranny has an intermittent no start. I've discovered that when this happens there is no voltage on the line to the coil of the relay on the fender. This points to either the neutral safety switch or the ignition switch or the wiring in that direction. (The glow plug relay does trip so I don't think there is a mechanical problem with the ignition switch.) Is there an easy way to narrow this down without just replacing parts? I Really Don't Want to have to get into the steering column to do that switch.

And a bonus question: How painful is it to do the neutral safety switch? If the recovery requires not more than one beer I'd do it myself. Otherwise I've got other things to do with my time.

THANKS!!
 

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A common issue with newer trucks (and probably the OBS as well) is the shifter mechanism bolts loose under the steering column. Will it start if you fiddle with the shifter a bit or put it in neutral instead of park?
I believe on the E4OD the neutral safety switch is part of the DTRS (Digital Transmission Range Sensor - fancy name for a position switch) that's mounted on the side of the transmission. If it isn't just the loose shifter bolts, you can troubleshoot by disconnecting the start wire at the relay (so the engine won't start) and work your way back from the relay to the DTRS, to the Jumper block where the clutch position switch would be on a manual, to the ignition switch itself. Check for voltage at each component when you turn the key to start.
 

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Discussion Starter · #3 ·
Thanks, KLHansen. That's a big help. I have tried moving the shifter and I don't see a change. That is, I still get the no crank when in neutral or park, and moving the shifter with the key on doesn't resolve it. It will crank after multiple attempts, but the frequency of the problem is increasing, so whatever is the cause, it is getting worse.
 

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Hi folks:
My '96 with the E4OD tranny has an intermittent no start. I've discovered that when this happens there is no voltage on the line to the coil of the relay on the fender. This points to either the neutral safety switch or the ignition switch or the wiring in that direction. (The glow plug relay does trip so I don't think there is a mechanical problem with the ignition switch.) Is there an easy way to narrow this down without just replacing parts? I Really Don't Want to have to get into the steering column to do that switch.

And a bonus question: How painful is it to do the neutral safety switch? If the recovery requires not more than one beer I'd do it myself. Otherwise I've got other things to do with my time.

THANKS!!
The starter needs voltage in the "Start" position only, the glow plugs in the "Run" position (and maybe also "start") so, in any case, the starter and glow plugs are not activated by a common terminal on the ignition switch so the ignition switch could, indeed, be faulty.
 

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Discussion Starter · #5 ·
Thanks, Donald. I'm hoping it's not the ignition switch. I've been into that part of the column before to do the bearings and it's not a fun thing. I'll post a followup when this is figured out.
 

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The ig.sw. is about the easiest thing on the column to get at - it hangs down from the bottom with 3 easy bolts (one in the center of the connector). This shows how to test it:

(click this text)
 

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Discussion Starter · #7 ·
Thanks for the info, Steve. We'll see what happens and I'll report back when we figure this out.
 

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Discussion Starter · #8 ·
Hi folks. Here's the follow-up. Being intermittent makes this a challenge but we checked the circuit to the relay coil and could not find a fault. Of course. When you want something to happen, it won't. But we also learned that the starter relay on the fender is a common problem, and the existing one was an aftermarket unit that had been on there for perhaps 15 years. It's so easy to replace and only about $40 so we replaced it with an OEM relay. After that there was no issue — it started every time.

We'll be putting about 500 miles on it in the next week so we'll see if that's it. If you don't see any more posts from me on this, then that was the problem. Thanks for your suggestions and help.
 
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