Scared of Electrical load on 240z Alt with big fans, etc...

[Hugh]

I have a nice set of electric fans I want to put on the car.. but its using the original alternator system with the 45amp (I think) alternator. The alternator is new and was bench tested recently. It works great. However... I'm afraid that running big electric fans in conjunction with my stereo, headlights, gauges, etc... will be a strain on the alternator.

 

This setup is only temporary, as the SR20 will go in with its ~85amp alternator eventually. I just don't want to toast the alternator and end up stuck on the way to work because of electric fans.

 

Anyone have anything to say on this?

[Tony240ZT]

Think you answered your own question. Put in a 280zx alt, or maxima alternator. A good 70amp one installs easily. Here is a post to the IZCC that should help. I've done this swap before, it's nice to be able to unbolt that extern regulator and clean up the engine compartment:

 

Date: Mon, 21 Oct 2002 19:46:07 -0500

From: Damian M Craig <craig001@mc.duke.edu>

To: z-car@taex001.tamu.edu

Subject: <L6> 240ZT no shut off

 

 

 

 

Kenny said:

 

>Hi Guys,

>I have a strange problem with my 1973 240ZT. The car starts on the

>first turn of the ignition ,but if I turn the ign. switch off, it continues

>to run.

 

I had this problem in my 71 240 with 82 engine/alt. Many thanks to

Ken Osman and Steve Golik who provided the solution:

 

When an internally regulated alternator is put into an early Z and

the external regulator is

removed, you often have the problem that the car will not shut off

when the key is turned off.

You have to put a diode in series on the wire that goes to the "L"

terminal on the back of the

alternator. The "L" terminal is the bottom contact on the "T" shaped

connector. You have to

connect the cathode of the diode (identified by a stripe on that end

of the diode) to the "L"

terminal and the anode (other end of the diode) to the wire that

previously went to the "L"

terminal. In my case (71 240Z) this was a white with black stripe

wire. This prevents the "L"

terminal current from feeding back into the ignition circuit when

the key is turned off. The

diode I used was a 1N5402, other people have used a 1N5400 or a 1N5062.

 

You can get the diode from Radio Shack or a similar electronics supply store.

 

Have Fun

[Muskrat]

Also, it will make the installation of your SR20 alternator easier, as you'll have already converted to an internally regulated alt. Fewer things to go wrong on the big engine swap. Hope it works out!

 

EDIT: I would like to add that my stock 45amp alt has taken the abuse by my electric (1 x 12") fan and 6x9 speaker bar without so much as a hickup... if you can ignore the blinking dash and headlights with the turn signal on.

[Hugh]

heh heh... you made me laugh with that last comment. The electrical system in this car is crapola.

 

That is a nice idea to swap alternators now and get started on electrical upgrades before the big engine swap... however, I don't want to pay for an alternator I'm not going to use later.

 

Anyone got one I can borrow? Just kidding.

[srgunz]

Are you using Air Cond.? If not use the A/C circuit. The fans will not exceed the A/c load. Your car was set up to use A/C so the alternator is sufficient.

[Hugh]

Oh, ok. I have no AC whatsoever...

 

I might try it and monitor the system to make sure the volts are still pumping out ok without loss.

 

My crank fan contacted the shroud the other day.... what a wonderful sound that was