My first engine “build”

Alright, went to turn the key today. It cranked! …in the key Run position…😬

I have a wire in the wrong place and I think I know which one. But I’m not sure where I should have it run. The S terminal on the Starter Solenoid. That needs to go to a wire triggered by the start position on the key ignition. I’m thinking it’s on a switched 12v source. That being the 12ga. Wire off the HEI. I have it spliced into that and I don’t think that’s correct. That’s going to be constant power in run.

So, where is my start signal to come from?
 
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When I’m cranking on one video, you can hear a strong gallop in the rhythm. I found plug wires 2 & 4 mixed up. Probably good that happened and kept the engine from firing with the starter staying engaged.

Ended up I had my starter wires (S&I) wired wrong. Between the solenoid, firewall and dizzy.

Re did those and she lives!
 
So, what had wrong in the wiring. I followed a couple of YouTube Univ. videos on how a couple of guys wired their 4.0 with HEI… apparently there’s a different or I just got it wrong.

I had ignition start wire coming out of firewall and spliced out to S terminal and run into 12V feed on the dizzy. Then I had the tach wire from the dizzy going to the I terminal.

Don’t ask me why, just understand that I’m mentally handicapped with wiring.

After trial and error and plugging and unplugging and thinking about it, it made sense to disconnect the I terminal. Made no sense as to having the tach to that.

It was giving power in the run position for the key.

After stepping away and disconnecting myself, I knew I needed a start signal from the key to the S, but with all the different wiring diagrams and color discrepancies I wasn’t sure which wire or how to trace it.

Then I found the TSM diagram and stared at it until I could understand it. Now I have single switched 12v to the dizzy, notch wire right now and a single wire to the S terminal. Being a solid green wire it matched the TSM diagram.

All good. Still don’t understand how I ended up wired the way I was. This makes sense. But to wire all of that and only have two out of place, I’m pretty impressed with myself.
 
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Now that I can crank and run, I’m starting to look at the vitals.

Oil pressure is strong on a cold engine, so we’ll see after it warms up.

The alternator gauge is jumping all over the place! Checked all grounds from battery to frame to block to alternator, all good and solid. And good continuity from regulator case to battery negative post. Voltage at the battery is measuring 14.5-14.75 fluctuating.

I have the Chrysler 80amp alternator with heavy gauge positive wire rated for 100+ amps running to battery+ side post of solenoid then the field wires running to the regulator with the red spliced to a switched 12v on the fuse panel.

Anyone have thoughts on that?
 
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It will hunt like that if the voltage is close to topped off, but it self regulates so that’s not an issue, you will get steady state charging when there’s a significant load on it like the coil firing at higher than idle rpm
 
Shreddinlettuce said:
It will hunt like that if the voltage is close to topped off, but it self regulates so that’s not an issue, you will get steady state charging when there’s a significant load on it like the coil firing at higher than idle rpm
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So the gauge is going to bounce like that when close to full?

Safe to say, ignore it for now and see what happens?
 
Shreddinlettuce said:
I would disable that gage and get a usb/ voltage gage

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Interested Ooo GIF by reactionseditor
 
So I noticed that at high idle and increased rpm, it’s bouncing. When it’s off high idle, it’s fairly steady at 14v.

I thought this video was longer, but right at the beginning you can see and hear it at low idle and 14v, then I bring the rpm up and it starts dancing.
 
There are devices to smoothe out voltage for a gage, or an aftermarket gage would be set up for that, but that gage you have is it going to the battery post or the feed wire from the alternator?

Was this a Renix car?
 
mbalbritton said:
Gauge is wired behind dash through factory harness and to the alternator.

Not a Renix
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The volt gage should go to a switched 12v source not directly to the alternator, the battery in this case will be between the alternator and the volt meter and acts as a capacitor that will smoothe out the reading. You are probably getting the gage jumping due to magnetic interference from the alternator from the looks of it
 
Shreddinlettuce said:
The volt gage should go to a switched 12v source not directly to the alternator, the battery in this case will be between the alternator and the volt meter and acts as a capacitor that will smoothe out the reading. You are probably getting the gage jumping due to magnetic interference from the alternator from the looks of it
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here what I can tell you I know. A diagram might be best to show.

The only thing I don’t know 100% because I didn’t run the wires and it’s factory done is from the tach. I assume a ground and a power for light and a wherever they pull their signal from. Everything else in the diagram I did.
IMG_2721.jpeg
 
You need to measure battery power not alternator power if that makes sense. The sensor wire for the gage needs to be going to post battery power of the battery. The alternator wiring looks correct to me.

Tach is usually a signal wire from
The ecu, if you fretted that, you need a tach that can trigger from a plug wire

 
Cobbled together an exhaust this morning to hush this thing up! It’ll do to get things squared away and get to a muffler shop.

IMG_2729.jpeg


Then, Jumped a ground from the regulator case to the battery and also ran a jumper from the back of the gauge to the positive post of the battery. No change.

It reminds me of when I put an aftermarket fuel gauge in my old CJ and it would bounce around as the gas sloshed around. The gauge was trying to read exact as fast as the signal was coming, vs a slow…resistance (?) read like the OE gauge.

Anyway, moved on to timing. Found I was running way retarded. I was able to adjust to 8 degrees advance before the HEI cap bottomed out on the head. Probably should pull the dizzy and reseat it to give me more adjustment without the cap sitting on the head.

She runs pretty damn smooth!

 
I’ve been chasing a cooling fan issue for a few days. Getting quite fed up with it. I’ve narrowed it down to wiring or a bad switch. But I do have one thing in question for wiring.

The fan didn’t come with wiring diagram, just an instruction of black to ground, white to switched 12v, red to battery and blue to fan.

Kinda like this diagram I found online:
1788045599426.png


Fine, but the wires from the harness supplied weren’t exactly that. There is an Extra ground wire that looks like this. (note the ground between the fan, the relay and the switch)
IMG_2747.jpeg

image.jpg

I have tried it connected & disconnected with just the one ground and I still can’t get the fan to come on.

I have checked continuity left, right, up, down, switched, switch off, all checks good.

I have straight wired the fan through 12v and through switched 12v, works both ways.

I ohm’d the relay and it checks fine. I also swapped it in place of my fuel pump relay and the fuel pump kicked on, so the relay is good.

What befuddles me, is with everything wired up in either of the above wiring configurations, I jump the ground for the temp switch and nothing happens. Maybe I’m wrong, but if I pull the wire to the switch and ground it, that completes the circuit, or with the wire plugged in, I jump from the brass body of the switch to the wire post.

Maybe I’m missing something, or is the switch just bad?
 
well, I pulled the temp switch, brought it to a boil in some water and had continuity from body to connector. Cooled it off and no continuity. So the switch works.

I’m halfway wondering if I had airlock in the coolant system, but that doesn’t answer why I can’t get the fan to run when I jump it.
 
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