Help needed with wiring rad fan relay!

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Help needed with wiring rad fan relay!

Postby snwtoy » Sat May 13, 2006 9:13 pm

Car in question is not a toyota, but a daihatsu charade detomato.

When I got the car, and opened the fuse box, the top right was jumpered directly to the bottom left in the relay holder (relay long gone). In this configuratoin the rad fan only would turn on when the car got to operating temp (although it didn't due to a broken plug/wire but that's another story).

I couldn't find a suitable relay to replace the missing oem one with all the pins in the same orientation, so have had to wire in a standard bosch type.

This is how I have wired my bosch relay in, and my deductions from multimeter readings:

Two important things to note -

Both the rad fan, and the a/c condenser fan now switch on at the same time. I'm thinking that this is because the circuit now has the correct amount of current???

second, the bottom right pin circled in white, has nothing on it. It's not earth or power, with or without the ign on, and doesn't seem to be required? I'm a bit stumped, but also a bit tired so may have to come back to it tomorrow with a fresh brain.

Any help in the meantime much appreciated!

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snwtoy
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Postby Stealer Of Souls » Sun May 14, 2006 7:37 pm

Not sure about the blank connection. it will lead to something... otherwise they would've left it blank...

My only comment is swap the +12 constant and the +fan around... Prevents a live terminal that could potentially connect with metal... Slim chance but easy to avoid and not worth the risk.
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Postby snwtoy » Mon May 15, 2006 6:11 pm

Stealer Of Souls wrote:Not sure about the blank connection. it will lead to something... otherwise they would've left it blank...

My only comment is swap the +12 constant and the +fan around... Prevents a live terminal that could potentially connect with metal... Slim chance but easy to avoid and not worth the risk.


Sorry I don't follow your logic.. It's still 12v whether it's connected to 30 or 87... ??
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Postby Stealer Of Souls » Tue May 16, 2006 9:39 am

Yeah that's true. But because 30 is a wiper arm, when it's not connected to 87 it's connected to 87A. So when the fan isn't running there's a 12V connection to 87A. It's not really all that important, but if 87A somehow connected with earth you'd short you power supply and blow a fuse.
At the end of the day all the terminals would probably be covered anyway. But it's just one of those things that is considered "good practice", avoid exposed live terminals.
'86 AE85.5 Levin

I don't claim to know everything... That doesn't mean it isn't true....

Click here to see "My Black Hole"
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