[Built4thrashing]

Does anyone know if the Falcon Alternator is an easy fit on the H25a V6 motors?

My alt is not putting out enough charge to keep the 2 batteries charged.

Batteries are a 770cca N70
and a Optima 750cca D34 yello top


Every time isolator kicks in the voltage on the main battery drops too much and the isolator cuts out. Ive had to wire up an overide to keep the isolator on to charge the 2nd battery.

[atari4x4]

pretty sure tombutt did the falcon alt upgrade on his H20a

[shabz]

How often do you drive the car?

All i need to drive is about an hour each day to keep the second battery charged - and that's with the fridge in the back full time.

[Built4thrashing]

shabz wrote:

How often do you drive the car?

All i need to drive is about an hour each day to keep the second battery charged - and that's with the fridge in the back full time.

Ive done 3000kms in 2 weeks and after the first week i had a flat 2nd battery. the alternator isnt charging enough for both batteries. Plus the optima requires a large output to charge it.....it will re-charge from flat in about 30mins on a 100amp alternator.

atari4x4 wrote:

pretty sure tombutt did the falcon alt upgrade on his H20a

Ill have to have a look into that. cheers.

[tombutt]

yeah i did one on my h20 was very simple just get the alternator and have a play hardest part was getting it and my hands into the same area to fit it sv620 have hardly any room in the engine bay

[Gwagensteve]

B4T- where is all the power going? You have another problem. 60 hours driving on a fortnight will be enough to keep the batteries charged.

Steve.

[Built4thrashing]

Alternator is the problem. It charges one battery ok but as soon as the isolator kicks in it puts too much load on the charging system an the voltage drops to low after abiout 30 secs and isolator cuts out. then after a minute it does it again.

I thought alt was on its way out as its was playing games not long after i bought it

[Gwagensteve]

Sorry, I didn't realise you were implying there was a problem with the stock alternator, only that it wasn't up to the job of charging dual batteries.

60A or so will keep duals charged fine if it's in good working order. Obviously yours isn't.

Steve.

[Built4thrashing]

was at my mechanic this morning and we had a fiddle with the isolator and it seems to working a little better today. The Earth wire from the voltage sensing relay wasnt grounded perfectly and was loosing some voltage causing the isolator to read incorrectly. fixed that and its better but the alt is still struggling to keep up. With both batteries charging its only putting out at 13.1 volts and you can really hear the motor get loaded up. Ill leave it how it is till after australia day long weekend trip and see if it recovers a little.

Still keen to do the conversion as i would rather have an alt that doesnt have to work to its maximum every time i used the fridge overnight.

[shabz]

Can alternators be rebuilt to output more current? Could be an option if they can

[Gwagensteve]

shabz wrote:

Can alternators be rebuilt to output more current? Could be an option if they can

Generally it is, however, unless there is no possibility of running a bigger alternator it makes no sense to due to the cost. Additionally, more current produces more heat that a smaller alternator case isn't necessarily able to deal with.

Very high output alternators are now common in road cars - the new BMW X3 has a 210A alternator stock(!) they are sometimes water cooled and used as part of the thermal management system for the engine - when the engine is cold and the alternator is working hard, the heat from the alternator helps to bring the coolant up to temperature.

Steve.

[royce]

isolators cutting in and out is usually a sign of either too small a feed cable or bad connection somewhere, as the current rises the voltage drops and the isolator cuts out, then the load is gone and the voltage rises and it cuts back in

with all the driving you are doing the batteries should be well charged, doesnt matter how big or how many batteries you have, if they are charged they stay charged, they dont need more current to keep them there

I would start with measuring the voltage of both batteries before you start the car in the morning, if either are below 12.3 you have either battery or current drain problems

[Built4thrashing]

Isolator problem is fixed. I said that in an earlier post. (Bad earth on voltage sensing relay)

The issue that remains in the alternator is only putting out 13.2volts where it should be up around 14.volt. You can hear the alternator working hard when the isolator cuts in.


The altinator is struggling to keep up with the demand. Im gonna get an inline amp meter so i can measure the demand the electrical system requiring.


Ive got an EL alt sitting here so its not gonna cost me a heap to do the swap.

[TheOtherLeft]

Gwagensteve wrote:

Very high output alternators are now common in road cars - the new BMW X3 has a 210A alternator stock(!) they are sometimes water cooled and used as part of the thermal management system for the engine - when the engine is cold and the alternator is working hard, the heat from the alternator helps to bring the coolant up to temperature.

Steve.

Would the high Alt temps cause problems in Australia? Obviously not in Germany where it doesn't get about 30deg.

What loads would the X3 have to warrant a 210A alt? Or is just for the high heat output or maybe even longevity?

[TZAR]

Built4thrashing wrote:

Isolator problem is fixed. I said that in an earlier post. (Bad earth on voltage sensing relay)

The issue that remains in the alternator is only putting out 13.2volts where it should be up around 14.volt. You can hear the alternator working hard when the isolator cuts in.


The altinator is struggling to keep up with the demand. Im gonna get an inline amp meter so i can measure the demand the electrical system requiring.


Ive got an EL alt sitting here so its not gonna cost me a heap to do the swap.

Thats not recommonded from personel experience, all power though a cheap gauge so if it fails the you have no charging and you wont know why cause your gauge is fine. Hate them with a passion those things.

[jonno_racing]

i think u just need a new alternator..

[royce]

Built4thrashing wrote:

Isolator problem is fixed. I said that in an earlier post. (Bad earth on voltage sensing relay)

The issue that remains in the alternator is only putting out 13.2volts where it should be up around 14.volt. You can hear the alternator working hard when the isolator cuts in.


The altinator is struggling to keep up with the demand. Im gonna get an inline amp meter so i can measure the demand the electrical system requiring.


Ive got an EL alt sitting here so its not gonna cost me a heap to do the swap.

What are your resting battery volatges? do you have anything running off the aux battery overnight?

[Gwagensteve]

TZAR wrote:

Thats not recommonded from personel experience, all power though a cheap gauge so if it fails the you have no charging and you wont know why cause your gauge is fine. Hate them with a passion those things.

You'd need to use a shunt for the kind of amperages being dealt with in that application.

Like this:

http://www.jaycar.com.au/productView.as ... rm=KEYWORD

A good idea though - a much better indication of what's going on than a volt meter IMHO.

Steve.

[dhula]

What is the output of the OEM alt?

[Built4thrashing]

dhula wrote:

What is the output of the OEM alt?

60amps on the V6. not sure on the 4cly

[Built4thrashing]

Gwagensteve wrote:

TZAR wrote:

Thats not recommonded from personel experience, all power though a cheap gauge so if it fails the you have no charging and you wont know why cause your gauge is fine. Hate them with a passion those things.

You'd need to use a shunt for the kind of amperages being dealt with in that application.

Like this:

http://www.jaycar.com.au/productView.as ... rm=KEYWORD

A good idea though - a much better indication of what's going on than a volt meter IMHO.

Steve.

Thats what i was planning on getting.

[fordem]

Built4thrashing wrote:

dhula wrote:

What is the output of the OEM alt?

60amps on the V6. not sure on the 4cly

According to the FSM I have (SQ416, SQ420, SQ625) - the available alternators were 60A, 70A & 85A - my assumption has always been that the V6 had the 85A.

[dhula]

If the V6 does indeed have a 85A jobbie, I don't think there would be a need to replace it. Sound to me like it will need a refurbishment and that's about it.
Possibly some new brushes (unless it's a brushless, but being 2002 I don't think it will be), a bit of a clean and health check and it'll be a goer again.




Are the Falcon alts way cheaper to buy and refurb compared to the GV ones. If they are then it could well be worth the effort of an upgrade

[tombutt]

pretty sure mine was a 60amp unit on my sv620 the falcon swap was pretty easy hardest part is getting ur hands in there however grand vitaras have a little more room then the vitara

[fordem]

The FSM for the SV620 also shows an 85A alternator.

[tombutt]

im pretty sure mine said 60amp however it came on the engine when i replaced it so may not have been factory sv620. also didnt pay much attention to it as it ended up in the bin pretty quick

[Built4thrashing]

Had a quick look and i dont think it will be as easy as hoped. The alt bracket is completely different and its highly unlikely to fit. Ive chased down another alt so hopefully it fixes my problems