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My quick alternator fix has come back to haunt me

31w ago

52.5K

Stef Schrader is an automotive writer and Puffalump collector with a Volkswagen 411, a Porsche 944 and a Mitsubishi Lancer GTS.

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Last November, my Porsche 944 finished its first 24-hour race. That checked a major achievement off my bucket list, but it's also where my problems began.

My 944, racing in the 24 Hours of Lemons last year. Photo credit: Murilee Martin/24 Hours of Lemons Uber Gallery

My 944 ran perfectly until we got to the overnight leg of the race. The four big Hella 500 spotlights looked cool and period-correct on a car from 1984, but we simply couldn't keep them powered, and they got dimmer as the night went on.

The car ultimately got towed in with no electrical power at all at around 1:30 in the morning. I was trying to sleep, so the team got working on an alternator swap. I walked out of a trailer to the disappointing sight of my car sitting on jack stands with tools scattered all around it.

This is what I woke up to. Photo credit: Thomas Endesfelder

The alternator on my 944 sits just behind the radiator and fan assembly to the side of the bottom of the engine. A long bolt fits through the bottom edge of the aircon delete bracket as well as two top tabs at both ends of the alternator that sandwich the bracket.

That bolt is held on with a nut on the back of the alternator. This nut moves a C-shaped bushing in the back tab inwards as you tighten it, clamping down on the bracket to hold the alternator in place. An adjustable tensioning rod that runs from the bottom of the engine to the bottom of the alternator is what keeps the alternator belt tight.

We couldn't fit the bolt in from the front with the fans still in. To save time, my team installed the bolt backwards, where the nut tightened down on the bushing-free front tab of the alternator.

Hint: the blue part of this battery should be on the top.

This didn't work, either. We got towed in with no power again in the last moments of the race. I just figured that my spare alternator was dead, so we borrowed a trailer battery and hooked it up sideways in the battery box. This got the car through the checkered flag.

Once my car was home, I noticed that the belt tensioning rod had snapped off during the race. This meant that nothing was spinning the alternator to generate power. Perhaps the alternator didn't fit as snugly at the top with our quick fix and it put too much pressure on the tensioning rod, or maybe we didn't align the tensioning rod correctly.

The race car in its usual position at home.

Either way, I knew I had to fix this at home. I already wanted a more powerful alternator from a late 944 to replace it, as the 1986 car running the same race had no issues at all with powering its lights.

This view of the old early 944 alternator out shows how it looked with the bolt in backwards. The bolt head is too big, so it can't push the bushing inward like the nut does when the bolt is in the opposite, correct way.

Getting this late 944 alternator involved a series of delays. I ordered one from a local parts store, but it didn't come with all the pieces. We had to cannibalize parts off the alternator I turned in for a core refund to get the new one ready to use. By then, it was the weekend before Radwood, the 80s and 90s-centric car show that was coming to Austin for the first time, where I hoped to bring the 944.

The late 944 alternator doesn't come with a bushing in its rear attachment point. There's a threaded connection on the back tab instead, which makes fitting a bolt in backwards all but impossible.

This mid-install photo shows how little space there is between the alternator (the lone shiny piece near the bottom) and the fan housing (the big plack plastic piece to the right).

It was late, I was cold, I was running out of time, and the fan bracket still sat in the way of installing my alternator correctly. I zip-tied several hoses and wire bundles to the fan bracket, and just didn't want to deal with it.

So, my friend Charles drilled out the threads on a table, holding the alternator between his legs in the most safety-third way possible and I put that top bolt in backwards again.

I don't recommend this.

As I was testing out this fix the night before Radwood, I heard a loud clunk, and then my car's battery light came back on. Turns out, my car had ejected the bolt that attached the belt tensioning rod to the bottom of the engine, forcing me to borrow a spare nut and bolt from Charles's ran-when-parked 944 project car to make it to the show.

This isn't the best photo, but it shows my poor tensioning rod dangling in mid-air after throwing a bolt onto the road.

My car wasn't done throwing tensioner rod bolts. My engine bay was making an ominous belt noise as I was leaving the track last week, which is never what you want to hear from a 944. If the timing belt on a 944 breaks, it usually takes out other parts with it.

Fortunately, it was just the alternator belt, which was loose again. The tensioner rod bolt had popped off on the other end now. I had to swing by a friend's place by the track to replace it with a spare Subaru nut and bolt to get home.

The second bolt that popped off because of this "fix."

I now regret this quick fix. Surely there's a reason why that hole on the back of the alternator is threaded. Someone designed these components to fit together so that no one piece is overstressed and ends up flinging bolts off at inopportune times.

I'm going to remove the fans and install the next alternator correctly! It took two tries, but I have learned!

What quick fixes have you made that you regret deeply later?

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Comments (5)
  • I once bought a Peugeot 205 with little service history so I changed the cam belt which looked worn. A sensible person would have taken the opportunity to change the water pump at the same time but I was in a rush and of course 3 weeks later it developed a terrible bearing whine: Thankfully I replaced it before it seized.

    7 months ago
    2 Bumps
    • Oh no! Man, I know the water pump woes, too. The 944 water pump pees a little when it's really far gone, and mine decided to do this the week before the first race I'd planned to do with...

      Read more
      7 months ago
      1 Bump
  • Rather than making quick fixes, my method is to ignore the warning lights on the dash until either a) the car stops entirely and I have to engage a mechanic, or b) I sell it.

    7 months ago
    1 Bump

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