Bringing Power to Electrical, Testing Electrical System Prior to Engine Installation Options

[Highland]

If I connect the 12V battery (+) to the 2 red wires from the main wiring harness and the battery (-) to the chassis ground, will the electrical system power up when the ignition key is in the ON position?

The main harness is plugged into the relay board. Neither the alternator, ignition or injection harness are plugged into the relay board, but all the round relays are in place.

By electrical system I'm referring primarily to windshield wipers, headlights, and lights. I want to make sure they work before installing the fuel tank and engine.

[bdstone914]

It should. The power to the engine goes thru the relay board.

[lierofox]

Looking over the wiring diagrams that I have, of the battery + wires:

1 super thick cable goes directly to the starter motor.
2 of them go directly to the relay board to supply power for the fuel pump, heater blower, and rear defroster relays.

The important ones for what you're testing:
1 goes to the fuse box under the dashboard to fuses 10, 11, and 12.
According to the '72 diagram, that same wire goes to the ignition switch as well.
According to the '73 wiring diagram, they used an additional 5th wire that goes to the ignition/key switch instead.

[Tdskip]

Relay board issues aren’t unheard of. Testing all those leads prior to engine install is a good idea.

[barefoot]

Just for peace of mind, I added fuzes to the 4 un-fuzed feed wires :

[dr914@autoatlanta.com]

yes

If I connect the 12V battery (+) to the 2 red wires from the main wiring harness and the battery (-) to the chassis ground, will the electrical system power up when the ignition key is in the ON position?

The main harness is plugged into the relay board. Neither the alternator, ignition or injection harness are plugged into the relay board, but all the round relays are in place.

By electrical system I'm referring primarily to windshield wipers, headlights, and lights. I want to make sure they work before installing the fuel tank and engine.

[Highland]

Need more help. So I think I may have made a mistake by just plugging in the ignition harness and wiper/turn signal assembly without the steering column. I'm guessing the mounted steering column grounds everything?

When I switched the ignition on it started smoking. I immediately turned it off and tried again with no smoke and a faint clicking, but no lights or blower would turn on. No fuses were blown.

The switch looks fine and I had just sprayed it with dry lock lube, so I'm wondering if that was the source of the smoke. I also ohm'd out the ignition switch and it test per the diagrams I found in this link:
http://914world.com/bbs2/index.php?showtopic=275464

So my questions are:

1) Is the issue with the switch not being grounded in the column or is there another issue I'm missing here?

2) If the ignition switch test good with an ohm meter, is the switch still good or did I destroy it?

3) Where does the ignition switch "P" terminal go?

[lierofox]

That sounds like some other type of short... as far as I know there's no fuses going between the battery and the ignition switch.

In terms of what P goes to, that wire goes over to the turn signal assembly to provide power to the parking lights when the key is turned off. (With key off you can move the turn signal stalk and light up one side of the car's parking lights.)

[IronHillRestorations]

It's also possible to plug the engine harness in wrong. DAMHIK

[Highland]

Only the main harness is plugged into the relay board. No alternator, ignition, or FI harness.

Do those others need to be connected?

[lierofox]

Only the main harness is plugged into the relay board. No alternator, ignition, or FI harness.

Do those others need to be connected?

They shouldn't.

The relay board is basically just responsible for the FI computer, reverse lights, charging system, heater blower, fuel pump, and starter circuit. If you're just testing the main blower motor, wipers and lights, etc. those are all powered by the wires going from the battery to the front fuse panel and the ignition switch, you don't even need to have the engine relay board plugged in at all.

[Highland]

Ran into a few problems testing the front electrical system:

1) Headlights pop up and down and came on. I tried high beam and they busted. Lights still pop up and down normally but no longer turn on with or without high beam. Did I just coincidentally bust both bulbs or is there something else going on? No fuse blew.

2) Only the front lights are hooked up. Should both the side and top front lights come on with parking lights on? Are the side front lights suppose to blink with turn signal?, with emergency lights on?

3) Is the brown wire coming off the top of the climate controller necessary or just an additional ground?

[JeffBowlsby]

What EXACTLY was smoking? Smoke is usually from heated conductors that melt the wire insulation, which is visible. So what specific wires are melted?

[theer]

on 1) check the fuse(s) for corrosion where it sits in the holder tabs.

on 2) I believe the side lights are marker lights, only and do not blink at all. Single power wire feed and single filament bulb in there.

on 3). You need that brown wire connected to ground if you want to test the blower motor. The 3-wire harness from the blower motor connects to the three spade connectors on the top right of your photo.

[Highland]

My ignition switch smoked when I tried it without mounting the switch in the steering column. With everything mounted all seems to work. I'm guessing the steering column provides a ground for the ignition switch and turn signal stalk.

After the smoke I bench tested the ignition switch. There are no melted wires. I sprayed dry lube into the switch just prior to testing. I'm speculating the smoke was some of the carrier liquid flashing off.

I ohmed out all the fuse contacts. Could I have a defective high/low beam relay?

The fresh air blower works with the ground wire disconnected. I'm wondering if the wire is just an additional ground and the fingers are actually grounded through the mount.