For me, it was with a 1979 Chrysler Newport I bought for a song when I was young and in dire financial straits. Someone had replaced most of the fuses with 30A fuses because… well I have no idea. Idiocy I guess. The car did keep blowing blower motor and dash light fuses, despite the 30A ones. Also, the insulation for some ground wire had melted off completely under the dash and the wire had burnt in two. Someone had tied it back together in a bow! I investigated the electrical problems and found a dangling ground strap that had been abandoned after the installation of an aftermarket stereo. It was somehow positioned just right to contact the terminals from the fan speed switch, a very (un) lucky break. I repositioned it properly, replaced the fuses with the proper ones, and everything worked, even despite the bowtie ground wire. I drove that car for 5 years and while it was quirky, it was a tough old bird and never quit.
The worst was the Chevy repair with a cable around the exhaust manifold and the upper control arm mount. Chevy did that because of the bad engine mounts that would cause the throttle cable to be pulled when the engine torqued up off the mount. The problem caused numerous accidents.
We laughed at that tightwad goofball repair for years. If that cable tie had not been the most reliable part that GM ever made, we’d still be laughing.
There’s a number of them but one of the top tier ones anyway involved a rental car that belonged to what I shall call a “National” rental car company…
The dealer I worked for sold a number of new cars to this company and one day I get a repair order stating the car does not start and “May need an engine overhaul”.
On a months old Subaru with only 4k miles on it?
After pushing it into the shop and raising the hood, I was flat appalled. There was clear RTV silicone gasket sealer everywhere in globs. Intake, timing belt cover, head gaskets, valve covers, you name it. Someone had even broken the A/C compressor high pressure line and repaired it by wrapping the break with electrical tape and applying a handful of RTV over it.
We never did get the story as to how and who done it to this car; all we know is that it was rented out and ended up in western Arkansas where it had gotten an overhaul due to poor running for some reason. The car was eventually towed off without repair so it’s anyone’s guess as to where it went.
Whoever worked on that poor car must have used an entire case of RTV sealer though.
The engine compartment reminded me of one of those sci-fi movies where alien slime is hanging all over and the ominous music starts up…
The car probably wound up at auction
And some poor unsuspecting sucker probably bought it at a used car lot
I worked for a towing/repair shop. My truck was a Ford F600 with a 370 motor. After about 150K miles it needed rebuilding. I did the tear down on a night shift and properly numbered all the rod caps in the Ford manner. In the morning the mechanic who did the reassembly was fresh from a GM dealership and assembled it per the GM numbering of cylinders. As he torqued down the caps the engine got tighter and tighter. He went with the theory that the new bearings would loosen up once he got it running. It did run amazingly enough, for about an hour. The truck got a factory rebuilt engine after that.
Same guy, was going to do the front brakes on the same truck. In spite of the “L” stamped into the studs for the right front wheel, he managed to strip 2 of them and destroy a steel Budd wheel.
I ended up doing my own brakes and as they kept him on for his GM electronics knowledge, I wouldn’t let him add windshield washer fluid to my truck after that.
I suggest any repair involving duct tape