Starter Clicks Once but Won't Crank: The Missing Bolt on My 7.3 Powerstroke

Short answer: When a starter gives one click and the engine doesn't turn, the starter is getting the signal but isn't spinning the engine. On my 7.3 Powerstroke, the cause was a starter that was loose and missing its top mounting bolt. With all three bolts installed and tight and a new battery, the engine started.

The truck and why it sat

This 2001 Ford F250 belonged to my father, and I got it from him in a straight-up trade. It has the 7.3 Powerstroke and the 4R100 automatic, and it had been parked for about eight years.

The history matters. My father had ignition trouble, so he replaced the ignition. Then the starter went out, so he replaced the starter. After that, the truck never started again, and he set it aside. A new starter that won't crank is a strong hint that the problem is in how it was installed, not in the part.

The symptom: one click

The replacement ignition had been pulled back out when the problem didn't go away, so I turned the empty lock cylinder with a screwdriver. I installed a new battery first. With the key on, the fuel pump ran, every gauge lit up and the fuel gauge read full. The electrical system was clearly alive.

When I turned it to start, I got a single click and nothing else. My first thought was that the starter either needed shims or wasn't tightened all the way.

What I found under the truck

The starter was loose as soon as I put a wrench on it. Before dropping it, I disconnected the main battery, a step I should have done first.

With the starter down, the problem was obvious. There is a mounting spot for a third bolt at the top, and it was empty. The starter was held only by the two bottom bolts, and the bottom bolt was loose as well. My read is that the starter had been sitting slightly tilted.

The fix

I found a bolt in the shop that fit the top hole and had the same head size as the others. I mounted the starter with all three bolts and tightened them. Then I reconnected the battery and checked the oil. It was about a quart low, which was acceptable for a first start.

On the next try, the 7.3 started and ran for the first time in about eight years.

Why a loose starter can give one click

A starter has to sit square against the engine. Its gear has to mesh properly with the flywheel or flexplate, and on most engines the starter grounds through its mounting to the block. A missing bolt or a loose bolt can affect both. I can't say which of those stopped this one, but once all three bolts were in and tight, it cranked and started.

Common checks for a single click with no crank

These are standard checks, roughly from easiest to hardest. On this truck, I found the problem at step 3.

1. Battery charge. A weak battery can click once and stop. A fully charged 12-volt battery at rest reads about 12.6 volts. The 7.3 Super Duty uses two batteries, so check both.
2. Cables and terminals. Look for corrosion, loose clamps and damaged cables at the batteries, the starter and the engine and body ground straps. A truck that has sat for years is a prime candidate.
3. Starter mounting. Make sure every mounting bolt is present and tight and the starter sits flush. This matters most after someone else has replaced the starter.
4. Voltage at the starter. With help, check the voltage at the starter's main terminal while the key is held in start. A big drop there points to a cable or connection problem.
5. Single click vs no click vs rapid clicking. No click at all points toward the ignition switch, the park/neutral circuit or the starter signal wire. Rapid clicking usually means low voltage. A single click often means the solenoid is engaging but the motor isn't turning the engine.
6. Whether the engine turns. On an engine that has sat for years, make sure it turns by hand before you blame the starter. A seized engine can also produce one click.

Takeaway

If a starter was replaced and the truck still won't crank, look at how it was installed before you buy another part. On this F250, a missing bolt kept it parked for eight years.

The whole truck, from the walkaround to the first test drive, is on the 2001 Ford F250 7.3 Powerstroke build page. If you're bringing back something that has sat, the free "Will It Run?" checklist covers what to look at before you turn the key.