Motorhome engine starting Issues

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SUMMARY

The discussion centers on troubleshooting starting issues with a 1979 Dodge Fireball D450 5.9L motorhome. Despite replacing critical components such as the starter, battery, spark plugs, and distributor, the engine fails to start. Key diagnostic steps include checking for spark, fuel delivery, air intake, and mechanical integrity, as well as ensuring the functionality of the fuel cut solenoid and the presence of a neutral safety switch. Participants emphasize the importance of systematically isolating each potential issue to identify the root cause of the failure.

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  • Familiarity with engine ignition systems
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  • Understand the role of neutral safety switches in starting systems
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Automotive technicians, DIY mechanics, and motorhome owners experiencing starting issues with older vehicles.

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TL;DR
My 1979 Dodge Fireball D450 5.9l Motorhome. It has recently stopped running after having a starter issue.
My 1979 Dodge Fireball D450 5.9l Motorhome. It has recently stopped running after having a starter issue. I replaced the starter, starter relay, starter solenoid, spark plugs, distributor and router, battery, and cables, and it still won't start. The fuel pump and filter are good. Also, I have replaced the pin that holds the gear shifter on the steering column in place could that have set off a sensor or burned a fuse in the ignition?
 
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Welcome to PF.

What do you mean by "it won't start"? Does it crank and not fire? Does it crank and try to fire but won't run steady? Does it not crank at all (no starter solenoid "click")? What does the battery voltage read when you try to start the engine (before, during cranking, after)?
 
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In a case like this the first thing to do is ask yourself what you could have reassembled wrong.
 
Partition the problem.
It needs a spark, air, fuel and a sense of timing.

Starter motor.
Does the engine turn at normal speed, and in the right direction?

Fuel.
Does the fuel cut solenoid operate?
Is there an engine immobiliser?
Is the fuel tank and pump full of water?
How long was it sitting. Is the fuel old and stale?
Are plugs dry, or wet with unburned fuel?
If you spray an ether-based engine-starting-fluid into the air inlet, does it fire and run momentarily?

Spark.
Does the coil spark, and the spark get to the distributor?
Does the spark get from the distributor to the spark plug?

Air.
Is the air filter completely blocked or soaked in oil?

Mechanical.
Does the engine have compression?
Has the timing belt or chain failed?
 
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Welcome, Jimmy!

I believe that truck does not have any safety switch killing the ignition based on the position of the gear shifter on the steering column, but just in case, you could easily test how alive one of the eight spark plugs is while cranking.

https://www.harborfreight.com/in-li...SW86CCqe_Urin2Vq0TM2mobs_paa2EQxoCtNAQAvD_BwE
63590_W3.jpg
 
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Neutral safety switch will prevent the starter from cranking. No sense to allow cranking while disabling the ignition. Some unsuspecting person would run the battery down attempting to start if that were the case.
 
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