Alternator question? When do you need to upgrade?

[spencer.adams]

Hello, My name is Spence and I'm not new to VW Beetles, but it has been a very long time. I just bought a 1967 VW Beetle with metal sunroof. My question is when do you need to upgrade your Alternator? I'm planning on restoring my 67 Beetle. I want some modern technology in it like a modern stero with a few speakers nothing to powerful, no amplifiers. I also want to be able to plug in a GPS and charge my cell phone at the same time and lastly, I'm planning on installing a modern AC (air conditioning) Kit. How many amps do I need to run everything and would it be better to upgrade to a 75 or 90 amp alternator? Would that help to keep the headlights brighter? Appreciate any knowledge you can provide. Thanks

[Ol'fogasaurus]

Hello, My name is Spence and I'm not new to VW Beetles, but it has been a very long time. I just bought a 1967 VW Beetle with metal sunroof. My question is when do you need to upgrade your Alternator? I'm planning on restoring my 67 Beetle. I want some modern technology in it like a modern stero with a few speakers nothing to powerful, no amplifiers. I also want to be able to plug in a GPS and charge my cell phone at the same time and lastly, I'm planning on installing a modern AC (air conditioning) Kit. How many amps do I need to run everything and would it be better to upgrade to a 75 or 90 amp alternator? Would that help to keep the headlights brighter? Appreciate any knowledge you can provide. Thanks

To state the obvious: a generator puts out ~30 AMPs while a Alternator is good for ~55 AMPs. You need to add up all the loads you can put on the system at one time and then make a decision based on that. To cut to the chase: it is hard to beat a good Alternator now days. Also you can do some other electrical upgrades at the same time for no-worry driving.

Lee

Oh, and welcome to STF Spence!

[spencer.adams]

Thanks Lee. I'm planning on adding the electric ignition. I was asking when because I'm not an experienced mechinic. Other than adding up the amps, is there a good reason for going to a more powerful alternator? Would it hurt anything? Would it make the car more reliable?

[Ol'fogasaurus]

I run an alt myself on a glass buggy which I have rewired a couple of times now. It is different than a bug but still the same I guess. I also run an electric ignition conversion to a stock distributor. If you plan on using a stock distributor have it checked out for condition, and the advance components being free and working well. If you run an after market distributor I would also have it checked out just to be sure of what you are getting... not all seem to be the same.

Since you are not going to be a by-the-book restorer then I would look hard at doing the upgrade at the same time, if not sooner, than the electronic ignition conversion. With all that you want to add, I think you need to get some figures on their draw but either way I think you are going to be better off going "more modern" in your charging system. This is an opinion and it is worth about or something less than what you paid for it.

There are others here that are much more knowledgeable about this than I am so I would suspect that tomorrow, when they are able, you will get some other answerers that will have more information in them than I can give.

Have a Happy New Year and again, thanks for choosing to talk to us here at STF.

Lee

[spencer.adams]

Appreciate the info Lee. Looking forwarding to more answers. I will start trying to find the draw so I can find the answer. I hoping to have the 67 Beetle on the road and make it a daily driver in the next few months.

[aussiebug]

Hi Spence,

Welcome to the world of old VWs.

Your generator puts out 30 amps. The ignition system, both stock and electronic, uses about 4-5 amps. Your headlights use about 5amps each, your tail lights about 1.5 amps each, and a stock type radio (say 10 watts per channel) 2-3amps. That's a total of around 20 amps with everything running, so you still have about 10 amps left for charging the battery, which is fine. And of course in daytime you have more charging amps available since your lights are off.

A GPS and cell phone charger use only 1-2 amps combined, so you don't need to worry out those incidental loads.

So unless you plan on putting on spot lights and a killer stereo, you don't need to upgrade to an alternator just for the electrical load.

If the gen needs replacing for mechanical reasons (worn out) then the stock 55 amp alt is a good alternative -they are very reliable and don't need much if any maintenance.

All gens and alts put out 14-14.5 volts do they will not change the brightness of your lights, THATs determined by the headlight bulbs/beams themselves. The sealed beams used in the USA do limit your ability to get better lights. The Euro-code bulb and reflector lights used in most other countries means you can easily change the bulb to halogens for much better lights (I've been using Halogen bulbs since about 1972). As well as the brightness, the beam shape is part of the problem. The USA light code has a fuzzy patch shape of light on the road. The Euro code lights have a sharp cut off line across the road so the low beam lights can be pointed a little higher without causing glare to other drivers, and the beam has a 'kick' down the curb side so you can see further down the side of the road.

If you do decide to change to an alternator, make sure it's the internal-regulator type (only two connectors on top) not the external-regulator version (three connectors on top). Much easier wiring needed. The existing wiring will handle the stock 55amps ok if it's in good condition, but if you use the 75 or 90 amp alt, you WILL need to upgrade some of the wiring and fuses or you risk a toasted bug.

You'll need a new alt stand. The original gen stand won't work, so it needs to be an alt or universal stand.

The alt also uses a different belt. The gen belt is 905 x 9.5mm. You CAN use this belt with an alt, but most alts are fitted to engines with the larger doghouse fan, and so the combined load on the belt is higher, so a wider/stronger belt is used. Since it's wider it rides higher in the engine pulley groove, so it needs to be longer too...912x10.3mm.

Hope that helps.

[Ol'fogasaurus]

What aussiebug said is basically true but when I said " ... Also you can do some other electrical upgrades at the same time for no-worry driving ..." I was referring to other things that can effect other things. I got my first car in the late 50's, it was a '37 and the wiring was already bad (woven wire covering instead of the material wiring now has. I don't remember now if it was positive ground or not but some of my older cars had it). The chassis was rusty so the chassis grounding was bad and so on. Ground wiring is one of the biggest problems even on new cars so check all your grounding for sure.

Most of the bugs you see the wiring has been used and abused so if yours is like that then changing over is probably a good idea but not a necessity. If the wiring is OK then leave it and save the change over for later... assuming you still want to do it.

Lee

[spencer.adams]

Aussiebug Rob. Thank you for all the knowledge. That really shines a light on what I was looking for. Along with Lee's info about grounding I think this was help me more than anything else I read. I think in the end when I install all the components I want the 55 amp Alternator is the way to go.

How hard is it to change over to the larger dog house tin with bigger fan?

Thanks for the info guys. Your educating me and I plan to put it to use.

[E_bug]

Hello spencer . Welcome to stf.

Dont forget the grounds! Big voltage drop area.

[Buggin_74]

Generators only belong on cars that are own by the purist nazis who are hell bent on keeping their cars 100% original, there is a good reason they went out with the arc.


Alternators are far more efficient and charge at the same rate regardless of revs, a generator is rpm dependant which is where you will get into trouble if you are installing A/C.

The extra load of the compressor clutch, condenser fan and evaporator fan on a generator at night with the headlights and wipers on with the engine only idling would would not be charging.

[spencer.adams]

Do they make an alternator that will fit the older tin or do I have to go to the newer dog house cooler?

[aussiebug]

Hi Spence,

The alternator will fit any bug engine, but it needs it's own mounting plate so the pulleys line up.

If your engine has the older smaller fan which had the oil cooler inside the air steam for the left cylinders, this will have no effect on the alternator operations.

Changing to the doghouse oil cooler shroud and larger fan is a question of cooling, not electrical power.

The old arrangement was right at its limits with the 1600sp engine of 1970. So VW redesigned the system to move the oil cooler into its own separate box (the doghouse) and made the fan wider to improve the engine cooling.

If you are not sure what you have...the doghouse shroud has a box on the front side (front is front of car) of the shroud on the left side, and there's a rectangular exist duct through the front tinware over the gearbox. The older shroud is flat on the left front side of the shroud.

Buggin74, I think you are overreacting. As I said above, if your electrical load does not require more amps, the generator works very well. I agree that alternators provide more power but why change something unless it NEEDS changing.

[spencer.adams]

Aussiebug Rob thanks again. I appreciate the expertise. I'll check my fan shroud to see which kind it is. The motor was rebuilt with a 70 - 71 1600 engine block so I'm not 100% sure that they used all the single port engine components, i.e. the old fan shroud.

Buggin 74 I agree with Rob. We're all VW fans so let's keep it polite here. I like all kinds of VW's. When I go to a VW show I feel like a kid in a candy shop. Life is to short to make everything to serious. Thanks for your advice.

[Buggin_74]

Buggin74, I think you are overreacting. As I said above, if your electrical load does not require more amps, the generator works very well. I agree that alternators provide more power but why change something unless it NEEDS changing.

Rob, you wont get any arguments from me that a healthy generator is adequate for an all stock electrical system, I had one in my first bug for nearly 10 years but I've also got a modern stereo and A/C in my current bug and know how much extra load all the fan motors and compressor clutch and the amp of a modern headunit put on the electrics and how on the limits that is with a generator.
Spencer is planning on fitting A/C so may as well upgrade before rather than find out the hardway after that a generator is not going to be up to the task.
I'm just speaking from an auto electricians point of view here, why cut it so close? just 2 thermo fans on a condenser (often needed in a bug install due to lack of space) can easily draw over 20amps and that isnt taking into account the evap fan and the compressor clutch.
anyway whatever works for you.

[aussiebug]

Hi buggin,

On re-reading the original post I do see the reference to A/C. Missed that with the first read, but I did sort of cover it in my first post when I spoke about the normal electrical load for a bug.

Back in the days when bugs could be bought new, Australia had never heard of A/C in bugs, and not so often in other cars either back then. For example we did not get any bugs with the under apron slots for an A/C condensor like the guys in the USA got. So for me, thinking A/C and bugs in the same thought is quite foreign

I still have the original generator in my 70, it still works fine, with only one rebuild, after almost a 1/4 million miles. I had 2x60w spot lights on it for a while, and charging was just barely adequate then, but with halogen headlights ( as you know, Aus stayed with bulb and reflector headlights so halogens are just a bulb swap) I don't bother with additional spot lights, even though I've done a lot of night driving, and have never had a problem with 'enough' electrical power.