Club 80-90 Forums

I been recommended this place to upgrade my defunkt alternator for my 2.0l '83 Aircooled devon. https://www.unitexchange.com/
They can fully rebuild it as a 65amp  for £110 +vat, or they think they may be able to upgrade it to 120 amp for an extra £70 +Vat. They made this suggestion based on it being a camper. Maybe having two batteries to charge, it could be easier with higher capacity alternator, I don't know. 
I guess highest use scenario would be running the engine (electric fuel pump), 12v fridge, standard lights on full beam, wipers, 4 speaker stereo with a sub, 2 phones on charge, diesel heater running.
Does it sound like a worthwhile upgrade, or a waste of money for my setup ?

Has it ever had an issue charging your set-up at 65amp?

Hello,

120 amperes at 12 volts will give a theoretical 1.44 Kilowatts, or about 2 PS.
This will run a domestic air conditioner...

Your starter motor, depending on model is between 600-700 watts, passing about 60 amperes through the cable from battery to starter.
Observe the diameter of this cable.


Do you really want to feed up to twice this amount of current through your old van's wiring loom..

Save your pennies..go with the standard alternator.. buy a  spare regulator and fan belt.

I hope I misunderstood about you using the STATIONARY diesel heater when DRIVING...

Cordialement,

Smiffo wrote: ↑30 Oct 2021, 18:31 Has it ever had an issue charging your set-up at 65amp?

No, I haven't had any issues as far as I know.

sarran1955 wrote: ↑30 Oct 2021, 18:41 Save your pennies..go with the standard alternator..

OK. Thanks both. I'll stick to the like-for-like rebuild.

sarran1955 wrote: ↑30 Oct 2021, 18:41 I hope I misunderstood about you using the STATIONARY diesel heater when DRIVING...

Not sure what you mean by stationary diesel heater. It's an autoterm diesel heater if that helps. But, yes I did mean while driving.

Surely the cu engine alternator is 45 amps? 65 amps would be a nice boost to recharge a leisure battery faster, but a heavier cable from the alternator would be very wise.
I use my diesel Eber' on the move regularly, and on long journeys to Devon in the Winter. I have however routed the burner inlet and exhaust with a 65mph wind in mind!

Hello,

Rosie n' Jim wrote: ↑31 Oct 2021, 07:54
I use my diesel Eber' on the move regularly, and on long journeys to Devon in the Winter. I have however routed the burner inlet and exhaust with a 65mph wind in mind!

I am prepared to stand corrected, but the only eberspacher heater I have had on a VW for use while moving was on my 1971 411 LE Variant. It had a safety cut off mechanism under the rear seat squab in case of violent deceleration. It would shut off the fuel flow instantly, the electronics (as such) for the heater were on the dash.

While I am at it, should not aftermarket electric petrol pumps do the same thing ?, rather that running on until the ignition is shut off in the event of an accident. Modern vehicles have the pump in the fuel tank.

Under the EU regs introduced 2 years ago, the fitting and operation of these things are strictly controlled, and as most of these Chinese heaters are not EU homologated, you fit them at your own risk and peril. In case of non conformity your insurance is cancelled.

I appreciate that EU regs no longer concern the UK, but as I am preparing my T3 for the VASP certificate, I have to conform with the 12 page guide, currently sealing my gas bottle compartment from the rest of the vehicle and changing my 1981 gas hob for a new one with thermo-couple safety valves....

Cordialement,


 

65A would be more than enough. 120A would overload the drive belt which is really only good for 90A, it also has to drive the heater fan.

Thanks all. I'll not go for 120A then.
From the part number it looks like mine is actually 45A. In an earlier post it was said 45A and 65A are interchangeable. Does that mean I can go to 65A without upgrading the alternator loom ?

Under EU regs - Directive 70/156/EEC ( dates from 1970! )- repealed in the UK, plus 2007/46/EC (for new vehicle models from 29/04/2009), for light commercial vehicles which in a lot of cases does not apply to these vans being campers and passenger vehicles and due to age. (Taken from the installation docs for a Webasto Air Top 2000STC)

5.3.8 Automatic control of the heating system
5.3.8.1 The heating system must be switched off automatically and the
supply of fuel must be stopped within five seconds when the vehicle’s engine
stops running. If a manual device is already activated, the heating system
can stay in operation.  ( my emphasis )

A lot of heaters that I have in have come from commercial vehicles and they have a relay that switches off the heater in the event of the engine run signal being switched off. They then need an override button for usage when stationary! No such relay needed for non- commercial.
Anywhichway, there are no regs stated in the installation notes that prevent operation whilst in motion, indeed that is one of the main uses in vehicles like ambulances, boats etc.
 

MagicWagon wrote: ↑31 Oct 2021, 10:11 Thanks all. I'll not go for 120A then.
From the part number it looks like mine is actually 45A. In an earlier post it was said 45A and 65A are interchangeable. Does that mean I can go to 65A without upgrading the alternator loom ?

Yes the loom was the same if it has the three pin alternator plug. If it is rebuilt with the bolt connections you will have to change the connectors to the ring type.
 

Ok. Thanks. I'll make sure I have it rebuilt with the same connector type. Cheers

Quote
While I am at it, should not aftermarket electric petrol pumps do the same thing ?, rather that running on until the ignition is shut off in the event of an accident. Modern vehicles have the pump in the fuel tank.

I totally agreen.  I use a Rover inertia switch on my electric fuel pumps. If I give the kitchen unit, close to the switch, a really good thump, it kills the pump. Useful addition securit device, the van dies after a couple of minutes driving.
Oddly, I hadn't thought of fitting one to the heater, but it's on the list now.

Rosie n' Jim wrote: ↑31 Oct 2021, 14:15 Quote
While I am at it, should not aftermarket electric petrol pumps do the same thing ?,

Yes they should, either through a tachometric relay, inertia switch or a relay controlled by the oil switch.