Alternator upgrade

[vegas602]

Hi, I have a 1968 mk2 340 that is currently pos earth. I'm looking to change polarity and wondered if anyone has any comments on the dynamo to alternator upgrade kits out there ( I believe both SNG Barret and Watjag do kits), the only restriction being my car has OE power steering. Any thoughts would be appreciated.Phil

[Martec]

Nodoubt you have looked at the kits, so what do they include?

I'm running a 420 front axle with 420 power steering and an XJ6/XJ40 pump and a 65 amp alternator, made up to suit. Power steering pump driven from a second drive pulley.

Brian

[Dave_W]

Hi Phil
I fitted a Dynalite rac023 made by Powerlite to my mk2 they convert your dynamo to a alternator so it still runs the power steering pump. I shopped around there suppliers and found one for around £400. The advantage being it still look like the original dynamo.

Dave.

[vegas602]

Thanks guys, I'm still awaiting some details/phone backs on whats available. The sng barrett kit apparently includes everything needed to change the dynamo over to alternator, with the new alternator being approx. 55amp. thought it might be closer to 65, although to be fair I don't know what the output on the original dynamo is.

[Martec]

The real question is what is the electrical load of YOUR car?

I was using 45 amp alternators (always a spare in the boot) and they would blow a leg when ever it was bad weather (lights, wipers and heat rear screen on).

My local electrical factor tested the load and it easily exceeded the 45 amps due to a high ampage rear screen heater (from New Zealand). Hence the 65 amp alternator now fitted, I also noticed that a kit for E types had a 65 amp alternator!!

PS I don't care what mine looks like under the bonnet with alternator, power steering pump, plastic water washer bottle, expansion tank, gas evaporator, geared starter, coil pack and many others as long as it works. After 16 years and many miles of continental holidays I think we are slowly getting there!

PPS the output from a dynamo is lower than an alternator so you will need an uprated feed from the cable/cables from the alternator to the starter solenoid and a higher rated ammeter (mine is from an S type or 420 I think).

Best wishes
Brian

[piman]

Hello Vegas,

I did reply after your original post but it does not seem to be here now?

I mentioned that my 1962 model has a diode as surge suppression across the fuel pump points, and this either needs reversing or replacing with a negative earth one. If your car has a capacitor then it does not matter. The other point to remember is to reverse the coil polarity.

Standard dynamo is rated at 25 or 30 amps depending on what is fitted, with a 35 amp available as an option.

Alec