switched power in the engine bay
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Drifting
Joined: Dec 2004
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From: Atlanta
switched power in the engine bay
I'm installing Carl's electric fan conversion (I know this has taken far longer than it should, but garage time is tough) and ran into a problem. I will of course call Carl tomorrow, but wanted some input. The instructions say to tap into the red/white wire connected to the 14-pole connector at the jump post. I tapped it and got no power, switched or unswitched. So I pulled the connector apart and red/white is terminal 7. Testing every terminal, I've got switched power at all EXCEPT 7 and one other.
So I pulled out the electrical diagrams. In my '83 diagrams, I can't find any reference to terminal 7 anywhere. In fact, it only lists connections for 2,3,4,5,6 and 9, when I've got more than that. I also checked '82 and no reference. The only thing I could find was in the '84 diagram which says terminal 7 is the aux. air valve.
Two things. My car was originally sold in California and no longer has any emissions equipment, and it also has a Clifford alarm installed which works fine. What in the world is the red/white wire at terminal 7 connected to and failing that, where should I connect for switched power in the engine bay?
So I pulled out the electrical diagrams. In my '83 diagrams, I can't find any reference to terminal 7 anywhere. In fact, it only lists connections for 2,3,4,5,6 and 9, when I've got more than that. I also checked '82 and no reference. The only thing I could find was in the '84 diagram which says terminal 7 is the aux. air valve.
Two things. My car was originally sold in California and no longer has any emissions equipment, and it also has a Clifford alarm installed which works fine. What in the world is the red/white wire at terminal 7 connected to and failing that, where should I connect for switched power in the engine bay?
Craic Head
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I thought those electric fans were usually set up to run from the 'jump post' with a thermo switch in the upper radiator hose to turn it on when the water gets to a certain temp.
This would let it run after you shut the car down just long enough to cool things off (like most newer cars do).
This would let it run after you shut the car down just long enough to cool things off (like most newer cars do).
Thread Starter
Drifting
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From: Atlanta
That is true and this harness is designed to tap both switched after the 14-pole connector and unswitched through the jump post, via a relay. Just that my wire according to the instructions is completely dead and I'm wondering why, and if so where can I connect instead. The other poles on that connector are for things like the oil pressure sender, coolant sender, etc, and they are switched.
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Drifting
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From: Atlanta
Oh crap, that makes sense. I haven't been able to start my car yet because of the new radiator, was just trying to finish up everything. I'll get it buttoned up tonight and see if that works. So what is that wire anyway? I still can't find it in the electrical diagrams.
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Electron Wrangler
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Its the fuel pump relay output (see 83 part I - page 97-157). It should activate for a short blip after you first switch the ignition on then turn off (this is the fuel pump priming phase). Then it doesn't turn on again until after it detects engine rotation - during cranking and when the engine is actually running. This is actually a very reasonable choice for this since if the engine stops this will go off again.
A slightly better choice would be to use the starter solenoid (pin 14) as a ground for the relay coil and feed the other coil connection from both this pin 7 via a diode plus also from the thermal switch (fed from the jump post) also via a diode to control the fan after running.
Why - using the starter solenoid as a ground means the fans will not activate for thermal or ignition reasons during starting - but can operate at all other times. You may also want to ensure the fans also run whenever the AC is on - you can use the compressor clutch control (combined in also via a diode) for this.
Alan
A slightly better choice would be to use the starter solenoid (pin 14) as a ground for the relay coil and feed the other coil connection from both this pin 7 via a diode plus also from the thermal switch (fed from the jump post) also via a diode to control the fan after running.
Why - using the starter solenoid as a ground means the fans will not activate for thermal or ignition reasons during starting - but can operate at all other times. You may also want to ensure the fans also run whenever the AC is on - you can use the compressor clutch control (combined in also via a diode) for this.
Alan
Last edited by Alan; Jul 17, 2009 at 05:09 PM.
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Thread Starter
Drifting
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From: Atlanta
Well that explains why I couldn't find it. My pages go from 97-155 to 97-159. 157 is missing. 
And thank you for the explanation, makes perfect sense now and is a good place to tap into switched power. I'm going ahead with Carl's connection, but will definitely save your suggestion for improving things.
You can find a pic of the tap in Carl's installation guide here.
Replacing the Belt Driven Fan
And thank you for the explanation, makes perfect sense now and is a good place to tap into switched power. I'm going ahead with Carl's connection, but will definitely save your suggestion for improving things.You can find a pic of the tap in Carl's installation guide here.
Replacing the Belt Driven Fan
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Electron Wrangler
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So instruction 16) is the one that is misleading...it should say "will have power only while the engine is running"
Alan
Alan
Last edited by Alan; Jul 17, 2009 at 07:08 PM.
Thread Starter
Drifting
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From: Atlanta
Yep just a little misleading, and since I couldn't start my engine I didn't know where the problem was. I'll be finishing it up this evening and hopefully finally posting that this stuff is done.
Thread Starter
Drifting
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From: Atlanta
blowing the in-line fuse
Everything is installed but I need some help from the electrical gurus, which I am definitely not. I've got both direct and switched power, but it's blowing the 25W inline fuse. I've got a test light and volt meter, but not sure how to trace down the problem. Anyone got a few hints on how to get started? Here's the relevant info from the installation pages. I did email Carl, but I wanted to see if you guys can help too.
