Alternator replacement? Voltage regulator gone bad?

[KevAndAndi]

My alternator light came on. The battery is fine; it tested at 12.8v. I let it run down to about 12.5v and then tested the battery terminals at idle. The reading was 12.3v. It did not change when the RPMs were increased to 2000. Then I tested the alternator. The reading was similarly 12.3v, whether at idle or at 2000 RPM.

I was considering the 95 amp unit from Autoricambi. That is backordered, though. As a result, I was looking at the Vick 65 amp unit: http://www.vickauto.com/newstore/index. ... ts_id=4261

Has anyone tried the Vick alternator? Any thoughts as to how it compares to the Autoricambi alternator?

[Edit: I changed the title of the post to be more helpful for searchers in the future.]

[spider2081]

If you have the stock Bosch 65 amp alternator have you removed the voltage regulator and inspected the brushes? You could just have a bad regulator and they are $20-$30 easy to change on the car.

[KevAndAndi]

If you have the stock Bosch 65 amp alternator have you removed the voltage regulator and inspected the brushes? You could just have a bad regulator and they are $20-$30 easy to change on the car.

Thanks, I actually came back here to amend my post to include this question. Where exactly are the brushes located and how does one know they are bad and the culprit for the failure?

[spider2081]

On the back side of the alternator there is an assembly held on with 2 straight slot screws. usually its a black rectangle but some replacements are shaped different. Carefully remove the screws. (they are easy to drop) Then the regulator/brush assembly sort of tilts from the top and out to remove. I would replace it and see what happens. If it does not fix it you will have a spare. Also I like to use local small independent alternator repair shops to test and repair my alternators. I know, many do not agree with me but I believe the original 65 amp Bosch alternator is a great product and all our cars really need.

[ORFORD2004]

Autoricambi is suppose to have them in stock this week... I wait for mine

[81SPIDERMATT]

x2 on the regulator .... I think I had mine tested at autozone or the likes ... their test showed that it was the regulator and not the alternator ..... easy to fix on the car .... 2 screws and done as spider 2081 suggested .... and I did toy with the 95 amp replacement idea but when it ended up being just the regulator that idea left

[KevAndAndi]

OK, I just removed the voltage regulator. Those two things in the back are the brushes, I presume.



I'll go ahead and order a new one and see if that cures the problem.

I was toying with the idea of removing the alternator regardless, but I couldn't get the bottom bolt out, as the radiator was in the way. Now that the alternator is semi-detached, and I'm ordering from a vendor anyway, I'm thinking of replacing the belt. How much play should there be in the belt at proper tension?

[narfire]

To get the alt out, the bottom bolt is a 19mm on the back side. A bit finicky with the oil dipstick there. There should be enough room to slide it out with a stock rad. I also undid the bolt on the alt bracket ( 22mm? ) Top bolt and it came out easy, about 5 minutes of undoing things.
The reg should be between 13.6 and 14.2 V I believe. New ones are Way cheaper than a new alt. My replacement reg. was $12.10 cdn taxes in.
I find the 65 amp alt seems to be just fine for what electrical things I have.

[So Cal Mark]

both the 95a and 120a alternators improve the electrical functions quite a bit. Don't knock it until you've tried it. Remember, your 65a alternator doesn't put out 65a all of the time, and in fact it would never reach maximum output in your car

[KevAndAndi]

To get the alt out, the bottom bolt is a 19mm on the back side. A bit finicky with the oil dipstick there. There should be enough room to slide it out with a stock rad. I also undid the bolt on the alt bracket ( 22mm? ) Top bolt and it came out easy, about 5 minutes of undoing things.
The reg should be between 13.6 and 14.2 V I believe. New ones are Way cheaper than a new alt. My replacement reg. was $12.10 cdn taxes in.
I find the 65 amp alt seems to be just fine for what electrical things I have.

Thanks. I do not have a stock rad, however, I didn't think it was appreciably thicker. I've ordered the regulator, and I hope that cures the problem, because I'm thoroughly uninterested in taking the rad out.

As Mark said, there's a lot of customer satisfaction regarding the upgraded alternators. A Spider-owning friend of mine also recommended it. I just have a bunch of other expenses and tasks at the moment, so I'd prefer not to have to replace it now.

I have a Volvo XC90 to attend to, whose idler pulley seized, turning the serpentine belt into many smaller belts. The great thing about working on the Spider is that it has given me the confidence to work on our other vehicles. Though changing a serpentine belt on a transverse mounted V8 in a cramped engine bay is proving to be a bit challenging.

[spider2081]

If I remember correctly I left the bottom bolt in the alternator and removed the alternator and bolt together. It hit the radiator but was disengaged from the mount

When a car is designed and an alternator is chosen for a specific vehicle lots of things are taken into consideration. One major factor is the wire size required for the alternators output amperage. The wires used in the Fiat Spiders are sized for a 65 amp alternator. One interesting point dealing with "Hot Rod" vendors many of them make a point of this in their marketing and even provide larger wires with the alternator kits. Especially the wires between the alternator output and the starter/battery.
Another factor is the alternators rotor speed the pulley system is designed to keep the alternator rotating within performance limits. Arbitrarily installing a different alternator usually does not address the actual speed the alternator is rotating form engine idle to red line. Another point is the direction the alternator rotates. Alternators produce power turning either direction, however the fan behind the pulley is designed to cool the alternator for a specific direction.
Alternators amperage output is usually designed to be operated with a constant load of 80% of the the alternators rated value. So a 65 amp rated alternator would be expected to supply a constant 52 amps. Momentary loads like turn signals would not enter this calculation. Also the high charging current immediately after start-up would not enter and it should quickly drop to a trickle.
With everything turned on at the same time in a Spider the current draw should not exceed 52 amps. An alternator only puts out what the car asks for. So having a 100 amp alternator on a car asking for 40-50 amps serves no purpose.
Many people state the higher amperage alternators put out 14 volts at idle as this is a good thing. It could very well be the rotor is turning too fast at idle and will be too fast at red line.
Our 65 amp alternators are very simple design almost every part is currently available for them and they are extremely reliable. My 35 year old Spider has 177K on it a 65 amp Bosch alternator.

[Fiatlanta]

Alternator light...?

[KevAndAndi]

I'm installing a new belt along with the voltage regulator. Is it correct that the play in the middle of the belt should be about 1/2"?

[RRoller123]

That's what I do, no problems so far on any of my fiats.

[KevAndAndi]

That's what I do, no problems so far on any of my fiats.

Thanks!