Dumb Question, but... Switched Power Source?

Posted August 16, 200915 yr

comment_292089

Hi all,

I am finally making good progress on the 240 and am VERY close to firing it up for the first time. I have done a lot of searches, but this simple issue eludes me.

I have installed an aluminum radiator with electric fans. I have a thermostat control switch with a relay for the fans. There is a constant power source to the fans directly from the battery, but there is also a lead that needs to be attached to an ignition based power source.

Here is the dumb question: Where can I find an ignition power source? There are no extra connector points on the fuse block (all of my old cars have had 12v spade terminals available). Just the basic glass fuses.

I have added an oil pressure switch in line with the fuel pump wiring (spliced in behind the radio). I might be able to tap off of that, but do not want to overload that circuit with the pump and fans in the same line.

Is there a simple source that I can connect the fan relay to? Wiring diagrams are not my strong point and I hate electrical gremlins. Any "easy" ideas are appreciated! Pictures are even better!

FYI... Here is my work to date... I'll post an "everything" writeup when I get it running.

Thanks!

Tim

Edited August 17, 200915 yr by SSuspect

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August 16, 200915 yr

comment_292091

The fan relay shouldn't draw more than a few milliamps so you should be OK to use the circuit you made for the oil pressure/fuel pump. You could also use the + side of the ballast resistor or coil depending on your setup. BTW I like the finish on your valve cover.

Steve

Edited August 16, 200915 yr by doradox

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August 16, 200915 yr

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comment_292093

doradox said:
The fan relay shouldn't draw more than a few milliamps so you should be OK to use the circuit you made for the oil pressure/fuel pump. You could also use the + side of the ballast resistor or coil depending on your setup. BTW I like the finish on your valve cover.
Steve

Thanks Steve! I have the ZX Dizzy setup so the ballast resistor is gone. The thermostat switch is mounted near the oil pressure switch, so I can tap into that cleanly and add to the existing wire loom.

Another dumb question: Should I tap into the power lead before or after the fuse going back to the pump? I have a 7.5a fuse running to the pump.

Just wanted to do something a little bit different on the valve cover. The intake manifolds are powdercoated the same color. Both are clear coated too. Why be normal...

Thanks again!

Tim

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August 16, 200915 yr

comment_292106

SSuspect said:
Thanks Steve! I have the ZX Dizzy setup so the ballast resistor is gone. The thermostat switch is mounted near the oil pressure switch, so I can tap into that cleanly and add to the existing wire loom.
Another dumb question: Should I tap into the power lead before or after the fuse going back to the pump? I have a 7.5a fuse running to the pump.

Just wanted to do something a little bit different on the valve cover. The intake manifolds are powdercoated the same color. Both are clear coated too. Why be normal...

Thanks again!

Tim

It should be fused, so the fuse needs to be between the thermostat switch and power. It sounds like after the fuse is what you want.

Steve