[trailwing]

I purchased a 1976 Firebird off craigslist as a summer project. I plan to swap my old Lemans engine in just to get a running, but I'd like to sort the wiring out before tear anything apart. It's currently missing the alternator and I don't have any power to anything in the car. Does anybody have anything to recommend?

[johnta1]

Actually most of the power to the inside comes from the wire (10 ga.?) that goes to the starter solenoid.
That wire usually goes to the wiring loom (soldered/crimped connection) next to the valve cover that goes to the alternator.

So, would need a starter hooked to battery or at least the red wire (10 ga.?) connected to the battery to get power inside.

[trailwing]

Yeah, with that wire connected, I still don't get any power. I assume the problem is in the fuse block or beyond. Is there a terminal on the fuse block I should be able to test for power? I probed most of the terminals and didn't get anything. Searching for fusible links.

[trailwing]

After a little diagnosis, the engine doesn't seem to be ground to the chassis. I don't see an obvious ground wire from the car to the engine. Where should I see one? Is there a ground coming from the wiring harness?

[trailwing]

Here's an obligatory picture.

[johnta1]

The negative cable on the battery is the ground to the engine/frame/firewall.

Make sure the battery ground is good.

The main junction of the red wire should be checked carefully.
Most of the power wires spread out from there, like to the alternator, to fuse box, AC possibly, etc.

On inside, the fuse box can be checked for power.
On firewall side, may need a piercing probe to see if wires have power.
(but that junction connection needs power 1st)

Follow the loom from the valve cover area to the firewall, make sure no cut wires?

[trailwing]

Originally Posted by johnta1

The negative cable on the battery is the ground to the engine/frame/firewall.

Make sure the battery ground is good.

The main junction of the red wire should be checked carefully.
Most of the power wires spread out from there, like to the alternator, to fuse box, AC possibly, etc.

On inside, the fuse box can be checked for power.
On firewall side, may need a piercing probe to see if wires have power.
(but that junction connection needs power 1st)

Follow the loom from the valve cover area to the firewall, make sure no cut wires?

My problem is that somebody had removed a bunch of parts and I could not measure continuity between the engine and the body. I temporarily installed an alternator and connected all the wires... The lights started working but I still wonder where the ground is? My Lemans has a small ground wire going from the body to the back of the engine. Regardless, I buffed over the crappy paint and rust for motivational purposes

[johnta1]

Usually the ground wire from firewall to head, some may have had one on each head to firewall.

Some later cars had a ground from head to frame rail around the rear of the control arm area.

The AC compressor I think had a ground wire in harness to the engine intake?

The lights in the doghouse had a ground wire from harness to the frame/sheetmetal?

Dash had some ground wires to dash frame?

[trailwing]

I could not find any place for a ground from the firewall to the engine but did notice a ground looking wire in the AC harness. I'm happy to see lights and hear an AM radio for now. Perhaps I'll find another ground when I pull the motor.


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[form74]

Should be one from the firewall to the top passenger side engine / Trans bolt,

Also I believe their is one from the another engine / trans on the passenger side, I can check in the morning on my car.

[Alvin]

Originally Posted by form74

Should be one from the firewall to the top passenger side engine / Trans bolt,

Also I believe their is one from the another engine / trans on the passenger side, I can check in the morning on my car.

Yes, IIRC aren't those (firewall @ least) the "braided" copper flat ribbon ground cables with crimped lugs on the ends?

[trailwing]

I didn't find any braided grounds but did find a heavier one from a passenger side transmission bolt.


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[form74]

Originally Posted by trailwing

I didn't find any braided grounds but did find a heavier one from a passenger side transmission bolt.


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Yep that goes threw trans to engine

Here is a shot of the braided line mine has been replaced as it broke but basically looks like the original

[Alvin]

Originally Posted by form74

Yep that goes threw trans to engine

Here is a shot of the braided line mine has been replaced as it broke but basically looks like the original

Yessir, thx that braided line is what I was remembering from days of

[ladytata]

There should be a ground that is on drivers side underbody, goes between the frame and body and bolts to engine. Its about a ft long. It's right under the cowls corner almost.

[ladytata]

And yes, braided passenger side, firewall to block, the headlight ground is on each corner of the core support, it's hard to see those , but feel for the little screw on each side, inside drivers side floor by front sill plate/kicker panel, and one by the e brake hande, thats hard to see also. Good luck, if you need pictures I'll do my best to get you some.

[trailwing]

Thanks for the response. The motor is out and I'm waiting on some cooling parts. Anyone know where I can get a th350 built fast in northern Virginia?

[trailwing]

The whole premise behind this project is to be cheap. This is a picture of the engine bay when I picked it up Saturday.



I cleaned and painted the inner fenders, radiator support and cowl. The engine is my 98,000 mile 1972 Lemans 350. I ran into a problem, in that the manifolds are different between the Lemans and the Firebird. This means that I either have to procure another set of downpipes or headers. The headers might be a cheaper option, but these heads do not have the outer bolt holes. Any recommendations?

[ladytata]

What # heads are on there now?

[trailwing]

7H1.