Electrical question

[D@vid]

Hi guys,

I've just ordered two new Bosch 44 amp batteries for my 1973 911T (mfi) but I want to be absolutely sure if these are right for my car (amperage wise)
Furthermore, I don't really know if I can start testing my electrical system when the engine is not yet installed.
So, can I start testing my (interior)lights/wipers etc. with the engine out?
I don't want to fry my new wiring loom...

Many thanks.

David

[timmy2]

You can test the circuits without your engine installed.
Just don’t hook up the fuel pump wires. Could make a mess!

[darrin]

D@vid -- make sure you're getting AGM-type batteries for your T (which will minimize leakage possibilities) == there have been a number of threads about alternate solutions (including using Miata batteries) - see, e.g. http://forums.pelicanparts.com/porsche-911-technical-forum/564510-early-911-battery-options.html -- Amperage-wise, even a VERY small battery (like a wheelchair battery) will start a 911, amperage ratings on car batteries go more to reserve power (i.e. ability to still start car if you leave lights on overnight) --

[D@vid]

Thanks very much Dennis and Darrin, you've been a big help.
Still a lot to do but aiming to get the engine back in this summer.
In the meantime, i'll be checking very carefully if I've connected all the wires the right way... scary stuff.
I will definetely disconnect the the fuel pump

Kind regards,

[PeteKz]

D@vid: Two thoughts: First, don't order the batteries until you are ready to run it. I would cancel the order if it hasn't already been shipped. Car projects have a way of taking longer than we expect, and you don't want batteries sitting around not being used.

Second, see other recent threads here about batteries. You don't need two batteries. Modern AGM batteries are more than sufficient to start the flat 6 engine, especially the older ones. I have a 1973 car too, and I only use one AGM battery in the right front battery box, and I'm cranking a 3.2 engine with no problem. I put it in the right box because I want to keep any corrosive battery fumes away from the fuse panel, and to help offset the weight of my ass in the left drivers seat.