Generator Light Stays on til 2800RPM - Toyota Nation Forum : Toyota Car and Truck Forums

Max in Australia · 05-05-2009, 08:49 AM

My (Daughters) 1994 2.2L Camry won't charge correctly.
I drive it up to 2800 and dash generator light goes off.
Cruising down to 35m.p.h. and at 1800RPM is fine.
Back off and revs drop and light comes on and stays on til I knock it back a cog and get to 2800RPM.
Is it a Diode plate problem?
Brushes?
Do they have a voltage regulator like my 1981 BMW Motorbike?
Any help would be appreciated.
Cheers,
Max.

***ASG14*** · 05-05-2009, 09:22 AM

Max, it is an Alternator. Generator's were used in older cars.

It sounds like the Alternator is going bad, but have it checked 1st. Most mechanics have a machine they hook up to the alternator and check it. If it comes back as bad, replace it with a remanufactured/reconditioned Alternator.

I would 1st check the Battery connection. Make sure it is corrosion free and not loose.

It's usually a simple repair, and very very common.

hill8570 · 05-05-2009, 10:53 AM

Most likely the brushes. If a electrical system test shows the alternator to be duff, I'd have a motor (electrical motor, that is) shop rebuild it -- I tend to trust rebuilt alternators and starters from auto parts stores about as far as I can throw them.

jmborchers · 05-05-2009, 11:00 AM

I would replace with NEW dealer part. As the other guy says don't trust the auto store parts they are junk.

***ASG14*** · 05-05-2009, 11:05 AM

^ The dealer gets the Reman parts fromt he same place as the Auto Stores. So getting it from the dealer won;t make a diff. I got a Defective reman Alternator from the dealer. And also a Defective steering rack.

Max in Australia · 05-05-2009, 05:06 PM

Thanks chums,
the fault seems to be universally agreed upon to replace the alternator.
Belt tension is taut thanks MR2.
I was hoping a (factory) new diode plate and brushes would do the job but the car has to be reliable and certainly things don't last forever.

I will let you all know how it goes.
Cheers,
M.

jmborchers · 05-05-2009, 05:22 PM

You could do the brushes but for the time and effort required then the regulator, diode and bearings aren't done.

This way it's once and done, even if he have the fault incorrectly isolated and it ended up being the regulator it's taken care of.

Max in Australia · 05-05-2009, 05:38 PM

Quote:

Originally Posted by jmborchers

You could do the brushes but for the time and effort required then the regulator, diode and bearings aren't done.

This way it's once and done, even if he have the fault incorrectly isolated and it ended up being the regulator it's taken care of.

Thanks JM,
There is a regulator there somewhere hey?
I was suspecting this due to the charging behaviour as this was happening on my 1981 BMW bike some years ago.
I'd like to try a replacement of this first before a more costly new alternator.
I'll be buying her a new battery too to ensure that is out of the equation. The present battery is fairly old.
Cheers,
M.

jmborchers · 05-06-2009, 07:08 AM

I suspect the voltage regulator is built in. The voltage regulator keeps the output at ~14V regardless of whether charge is needed by the car. If you didn't have the reg the output of the alternator could be between 16-48V or more.

The reason I don't think it's the regulator is because it's not outputting properly at low speed. From the description you need high RPM to create energy.

A bad cell in the battery can create demand the alternator can not make up for, making it appear like a bad alternator or brushes. To find out which turn the car off. Measure the voltage at the battery. It should be near 12V +/- 1V.

Turn the headlights on and try to start the car while measuring the voltage at the battery. If the voltage drops below 8V change the battery first and see if the problem goes away. A good battery will stay around 10V under load.

Simpler=Better · 05-06-2009, 08:52 AM

It's the brushes. Definitely. I had the exact same problem with my 82; the alternator would only work above 3k (and that's on an engine with a 4k redline!)

Don't know anout the camry's alternator, but on other cars I have worked with the brushes are part of the regulator assembly, making it very easy to replace them

Get new brushes, it's way cheaper($5-$10) than a new alternator.

Max in Australia · 05-06-2009, 09:58 AM

Thanks JM and Simpler=Better ..
I do have a small grasp of the workings of alternators and aye, the regulator is built into the Bosch in my Daughters '94 Camry.
As she is buying her first home and I am on a pension, I'll buy her a new battery first and then see about a new diode plate with brushes.
Then, if all else fails, a new alternator.
Cheers,
Max.

Max in Australia · 05-07-2009, 06:06 PM

Hi Chums,
Just a small report .. I've installed a new battery but have lost my glasses.. most frustrating.
Swapping dynamos today.
Will keep you informed,
Cheers,
Max.

Max in Australia · 05-08-2009, 12:56 AM

Friday arvo in Australia and problem fixed.
I unscrewed the clip on connection (Click on pic below) and inspected the brushes. The were protruding from their housing by about 3/8" or 10mm.
I took it to an electrician who sold me a regulator and brush blok for $50. The brushes were proud by about 1 1/4" or 30mm.
Straight forward installation and now charging like a bull.

Thanks all for your concerns.
Max.
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