Can a broken alternator cause problems in the fuse box?

If the voltage regulator is bad, I can see that the higher than expected voltage increased the current, causing the fusing to blow out. However, if the voltage regulator is good (if the voltage regulator is on the alternator, one would hope it is good), then the voltage should be ok. So the possible problems include:

1) Bad voltage regulator, leading to too high a voltage, causing the fuses to blow out. 2) The mechanic used the wrong fuses. 3) There is a short circuit in the circuits controlled by the fuses.

It should be easy to test for 1 with a voltmeter and 2 by checking the fuse ratings against the ones in the owner's manual.

If it is #3, some needs to go and figure where the short(s) is.

Jeff

Thanks

Something else they just told me while I was picking up my car:

I'm paying $300 for the alternator, while online the remanufactured ones go for $90. They said this is because the alternator I'm getting is new (this is a 1995 Prizm we are talking about). Does this make sense, or am I likely getting lied to?

That sounds a little expensive, but Toyota tends to be a little pricey. And, if you buy from a garage rather than online, you tend to pay list prices, which is also a bit high. You can try calling other dealers and see what they charge for a new alternator. However, a new alternator will usually be more expensive than a rebuilt.

So my guess is that you paid list price for the alternator, which is high.

Jeff

$300 for an alternator from the dealer is a bit high, but not out of line - first, they are really picky about the components they reuse, and often most of the functional parts of that alternator are brand new by the time they get done tossing out all the less than perfect core parts. And sometimes they don't have enough cores and just sell New as Reman and eat the price difference. ("New" would run you more like $400 - $500.)

And second, Toyota really stands behind the warranty on them.

Much different than the "rebuilt" alternators at your local chain parts store, where they sell on price alone and try to rebuild them as cheap as possible - and still sell it to you for $70 or more. I've had really bad days where the alternator died far from home, and the FOURTH "rebuilt" alternator I installed out in the parking lot was the one that finally worked.

By number three, I was seriously considering going to the Sporting Goods next door and buying a baseball bat (or a 12-GA shotgun) and make THEM come outside and bust THEIR knuckles changing alternators till they found a good one...

I don't give a flying fig what the bench testing machine says, they need to work when installed in a real car with real loads. And a "Lifetime Warranty" isn't worth anything if they fail new out of the box, or soon after installing, and the labor isn't included.

When I need a rebuild, I drive across town to a real auto electric shop and they rebuild my alternator properly, come back in two hours. And when I put it back in the car, wonder of wonders, it works. And keeps working for several years.

And the regulator can be intermittent - work fine for a while when still cold, and then go nutzo and spike the voltage when it gets hot.

Another possibility is shorted rectifier diodes in the alternator, that could blow fuses from really high levels of AC Ripple getting out, and the branch circuits see way too much current from the ripple going through to filter capacitors inside the devices and blow the fuse.

This would also more than likely rip up AM radio weak signal reception something fierce with alternator whine, and provide a clue.

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That's about right. I think your mechanic is making ~$15-25 on the part. You can get remanufactured from Toyota for about 15% less, but they are remanufactured properly and will probably last the rest of the life of the car.

But, looking at it parts wise, the stator and the rotor rarely go bad (unless this is a Delco alternator...then all bets are off...) so what does go bad is,

brushes.............~$4.00 at any True Value store Voltage Regulator...~$25-40 depending on the model Bearings............~$25 each, X2

So a whole rebuild would be about $90 and a couple hours on a Saturday. They aren't really hard to rebuild, but then, I used to assemble space suits and aircraft components, so I'm a bit more mechanically/electrically inclined than others. I think it's easy and have done it on a couple cars already.

replying to n.torrey.pines, Caged5days wrote: Did the alternator fix the problem