What could a mechanic do to fry both an alternator and starter?

So far so good on this. Had to use the truck today and it started without a hitch each time. I am really thinking I just got that many bad starters in a row. I usually turn the engine off and keep the key in the run position while coasting in a uncongested area at slow speed now to see if the starter will crank over. If not, I can pop start it. I did this several times before I had to stop today and it worked just fine.

I talked to the mechanic as well and he said his gut tells him it is the starter and not the clutch safety interlock or similar. He has done this a lot more than me but I figure that I won’t trust it completely for another month or more.

My other truck is at the shop and waiting to go in for some work, otherwise I would be driving it more with not completely trusting the starter on this one. They are pretty backed up with work like everyone else these days and I don’t think it has moved since I left it there.

Just keep in mind how long it took @ok4450 to find his problem with the ignition switch. Took an act of God and a whirl wind, and he’s a pro.

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Is the ignition switch itself something to consider as well? I mean there is always a click but what if it wasn’t a solid contact? Either way, I never got anything by bridging the remote solenoid so am thinking it might have just been that many bad starters. We will see.

I didn’t see the post about his ignition switch but if you could provide a URL, that would be great.

I moved some stuff on my property with this truck yesterday and it worked fine once again. I am really starting to think that I just got that many bad starters in a row. I was talking about this with another customer recently and he is into classic cars. He said he went through 3x in a row bad fuel pumps before he got a working one recently so I guess this isn’t uncommon.

See ok4450 stumped to this point. Very very long and frustrating.

The starter / solenoid was probably just a coincidence.

What burned up in the alternator? Was it one of the 3 windings? One of the windings may have gotten damaged during removal and resulted in a shorted winding which made it fail. If the engine to chassis ground opened up perhaps that could cause the alternator to go to full output but I think all the regulators are built in to alternators now so that wouldn’t be it, and alternators are designed to work at full capacity without damage anyway. Usually it’s a bad rectifier, regulator, brushes, or bearing that makes an alternator fail. A shorted winding (which makes smoke) is rare as far as I know. Are all the diodes good in the original alternator? Two shorted diodes could short a winding, but that shouldn’t do much at idle speed.

So far the truck is still starting and running fine. Basically, when I took the truck back to the mechanic, they replaced the alternator for free. I had already purchased a lifetime warranty model so they just swapped it at the parts store and got another one. I never saw the bad unit but know a fuse or link was blown and had to be replaced. Then I had to deal with the starter and solenoid issues which have to be partly related.

I think somehow the starter got shorted and that fried the alternator. I don’t see any signs of arcing but figure the didn’t disconnect the battery when doing this work. Of course the starter is bolted to the transmission and that had to come out for a clutch change. Somehow this has to all be related as none of this was a problem before it went in for the work.

A failed slave cylinder caused me to have a hard time shifting. While they were in there the clutch was done as well.

The fusible link from the alternator will open up when the rectifier on the alternator fails and shorts out. With the rectifier shorted, the alternator output would be shorted when the engine was started. This would lead to the alternator overheating after a few minutes. I don’t know how the rectifier could be damaged during an alternator removal.

They could have disconnected the link and let it touch the engine with the other end still connected to the battery, which would blow the link.

It all seems like it could be a coincidence too.

It was the starter removal that started all this. Maybe it was just a coincidence. Yes, the shop made mention of the alternator just smoking like it was going to catch fire so your idea of a dead short in the rectifier might be it.