New starter wont engage the flywheel

A month ago I was, scouting for turkey, driving on a rugged dirt road. I turned my truck off and went on a hike. When I came back my truck wouldn't start. The starter motor would hum but not engage the flywheel. I was on a hill so I popped the clutch and the truck started right up. When I got to camp, I was able to start the truck, with no problem, several times, and had no issues, until two days ago. I was on another dirt road, and this happened again! I was able to push start my truck and when I got back to camp, the starter motor would hum but not engage the flywheel. At this point I thought it was a bad starter. Lucky for me I was with a friend, and he drove me to the nearest town and was able to buy a new starter. After installing the starter I tried to start my truck and it did the same thing. The starter would hum but not engage the flywheel! I inspected the flywheel teeth and they look fine, from what I saw. What else could cause this to happen?

 

Not enough juice in battery?

 

@zerotimeouts The battery is four months old... also the ignition switch is brand new, OEM.

 

Seems like the hum means something is getting there. It's possible that a bad alternator killed or drained the battery and caused the starter to die. They tend to wear on each other altogether.

Not sure where the starter is on our trucks. there is an old school trick that you hit it hard with wrench or hammer and it will start. But not sure that still works on new starters.

Did you check battery voltage truck off/on? have you tried charging the battery off the truck and trying again? Also leave the voltmeter on when truck is off and look for parasitic drain when nothing is on or running.

these are just general electric troubleshooting stuff not tacoma specific

 

There is also a couple main relays you could try swapping them all out and see if that helps? I've never had that be the fix but they are usually cheap enough that it's not worth the time to troubleshoot.

 

Lastly check the connection to the battery starter just in case it wiggled loose. I had a car that was acting up and it turned out to be I didn't tighten the battery terminal after charging

 

Just in case this helps. I;'m sure there are other similar ones https://www.youtube.com/watch?v=0hCxzGpxVTw

 

@zerotimeouts The starter is brand new, replaced it two days ago. I just drove five hours, tonight, and the truck didn't die. Driving that distance, with my lights on, the alternator should be fine, right?

 

Quite possible if you got a off the shelf rebuilt starter it does not work .

Any more the starter should be tested before installing .

Time to break out the Meter and get some numbers

 

No the alternator could still be bad but providing enough power to run car and not charge battery. I use one of these (not this exact one) in my cars and check it out when I drive or you can hook up a volt meter to the cigarette lighter. If it jumps around or lets voltage in battery fade the alternator is bad and not consistently charging.

$12 Jebsens 4.8A 24W Dual USB Car Charger Volt Meter Car Battery Monitor with LED Voltage & Amps Display, Cigarette Lighter Adapter, Compatible with iPhone 15 Pro Max Plus 14 Samsung Galaxy S24 iPad Pro

https://www.amazon.com/dp/B01N00I4T...&pd_rd_r=e97b8bce-cacb-11e8-a928-ef882c0cd905

 

@zerotimeouts The battery is at 12.9 volts with the truck off and with it on its at 14.19 volts, so it's not the alt or the battery.

 

Test the voltage on the main power at starter. Then check the smaller start signal wire that plug into the starter next to the main power. When ignition is turned on, that smaller wire should be hot.

Also, check for faulty or loose ground at battery terminal, inside fender next to battery, and at the block next to oil pan on driver side. Those are the 3 main ground connection.

 

there are 2 mechanical actions for the starter to work properly. It appears that the electric motor portion works fine but the solenoid is not pulling the bendix in. The bendix is a spring loaded, lever operated mechanism that has the actual gear on it that engages with the flywheel. What doesn't make sense is that for the starter to turn, the solenoid has to be pulled in. Ill take a look at my spare starter tomorrow and take some pictures.

 

Check for loose wires, pinched wires, or a bad terminal end. Flexing the chassis out in the bush while hunting is probably pulling something and causing a short or a bad connection. Sounds like everything else is fine.

 

Yes starter bendix as stated fights against gravity (spring) force. If the solenoid isn't pulling in the main starter shaft will never engage with the flywheel. Maybe remove the flywheel dust cover and have a pal inspect.