SBC wiring questions that haven't been answered through "search"

Noob alert....FYI.

So I've currently got my SBC wired for test firing, nothing special. Batt Negative to block, batt positive to starter, points dist. negative to coil negative, coil positive to batt positive. I'm using a remote starter to fire it. I originally had a ballast resistor b/t the batt and the coil, but it kept the engine from turning over, then burnt the hell up! Probably because it was the el cheapo one. I'm currently doing *brief* test fires without the resistor, concerns being torching the coil and possibly burning the points.

Anyway, I'm in the process of wiring it to not run off the battery and ensure that I'm not damaging any components while I'm still learning how to tune the engine. Here's the diagram that I'm currently going off of:



I know from a previous post that the "Resistance Wire" going to Acc. isn't needed, so that's right out. This covers the alternator wiring (I think) so I'm not draining/recharging the batt manually

I'm wondering how exactly to wire up the coil and electric choke based on this diagram as a foundation. here's what I've come up with:



Questions:

-The ground coming off of the alternator can go to one of the mount screws on the regulator, correct? It's shown in the first diagram, but not in the second version.

-Having the choke connected in line with the batt like that could completely make the choke useless, as it's always getting current...which is one thing I've heard. Thus, would it be better to have the choke positive coming off of the field wire on the regulator?

-I bought a gauge cluster to use in lieu of the original while I refurbish it. How does the voltage meter insert into this diagram?

-A little OT for the electric, but since I mentioned the gauge cluster, what port on the intake does the Temp mount into? I'm assuming the one next to the water neck?

-Would it be advisable to completely replace the push button ignition system with new components when I get around to it? I hear that the original button grounds itself out and should be replaced for a 12v system.

-Once I'm comfortable with how it's running, I'm going to install a Rebel Wire kit that I purchased, 20 circuit. What aspects of my current wiring plan will be nixed when I install it, if any?

-I'm planning on mounting the regulator and resistor on the pass. side firewall. What's the best way to run the wires back and forth to the alternator? I was planning on putting them inside the corrugated wire wrap and trailing them along the top of the intake, below the carb, then zip tying it to the alternator mount. Here's my current set-up:



After I installed the throttle cable bracket, I had to move the coil to the firewall right behind the distributor, more on the passenger side, in the center indent. Hopefully that makes sense.

I realize that things like the cooling fan will be connected via the wiring kit, along with headlights, tail lights, radio, etc etc. I'm just not sure how much of my current plan would be negated/redone when I get around to installing it. Either way, coming back to the wiring kit after everything is tuned is the current plan, just curious as to what would change upon kit installation.

That's about all the questions I can recall at the moment. I'm sure I'll be back with more!

Thanks!!!

 

The wire going to the ballast resistor needs to come from the IGN. side of switch. And the elec. choke wire should be on other side of resistor so it gets a full 12V.

Voltmeter can tap into pretty much any circuit (+) that is "on" when in run position.

Water temp sender can go into one of the ports near thermostat housing, or in the plug on the side of either cyl head, in between the exhaust ports.

 

GOOD info...thx! In my case, since I'm not cranking it off of the ignition (a remote starter in this case) is it ok to have it wired as I drew it?

 

As long as it's starting fine, that wiring is OK. There was usually a wire to coil + that bypassed the ballast resistor and was only hot when cranking to give the coil a little extra juice. Your starter solenoid should have an extra small terminal for that wire, if needed.

X2 on moving the choke hot wire to the battery side of the resistor. Electric chokes are just timed by the bimetallic spring inside the housing. If the engine is warm, the spring has already expanded so the choke won't be on...in theory.

 

That extra wire might explain why I was originally having problems starting the engine by running the + to the coil thru the resistor only....then it worked fine when I disconnected it and ran it straight to the battery.

Ok, so having the choke + go directly to the battery side of the resistor won't negate the purpose of the elec. choke by already having the bimetallic spring already heated up? Maybe I'm misunderstanding how the spring works...I thought electric current affected it to do its thing, not engine temp.

 

The elect. current heats the spring slowly. If the engine is cold, this gives a timed opening rate for the choke plate (that's what the adjustment is for). If the engine is already warmed up, the spring is also warm (from engine heat), so the choke has already begun to open or is fully open on hot start.

You need the ballast resistor to save the points. Sounds like you also need the direct wire to get it started. DO NOT run that wire on the same circuit as the start button. If you tie it in with the starter, current will back feed from the coil and engage the starter while the engine is running. Look for the "I" post on the starter solenoid, or get yourself a double-pole push button (starter switch) and wire the coil + leg on the other side of the switch from the start wire.

 

You have enough wires to "hot wire it". I've done many of them in the same manner to test start them for a short period.

I showed a video of me starting a Cadillac 500 sitting on a tire in the driveway hooked up exactly as you have that engine on here the other day. The only difference was the 500 has an Hei.
Once you know it runs you can go back and hook up everything that needs to be hooked up to drive it.

 

The biggest fault I see with your diagram is you have the coil/ resistor hooked to a constantly hot power source. This will not only make it impossible to turn the car off, but it will also cause the coil to overheat and potentially even explode.

 

I hope this helps

 

No....the wire going to coil needs to come from switched battery power, not directly....through the resistor when running. Another wire from ign. ON can go to start side of switch, or a push button, and that wire can go directly to coil, so it gets a full 12V at start up.
The diagram directly above is correct....just doesn't show the start circuit.

 

Eeesh....ok, I just read about Tugmaster and 49RatFink's woes with these old starters with buttons. Seems like life may become a little easier if I just upgrade to a modern ignition?

 

Excellent point, I'll admit I ASS-U-MED it was going to end up with an ignition switch and a start button ...

 

Nothing wrong with the assumption, because I was up in the air as to what to do...keep the original setup or ditch it for a simpler/newer one. I'm glad to know about both because it's helping me decide which way to go. I'll reiterate a point about myself....I'm a noob and I don't want to destroy parts I paid good money for because of ignorance! I'd rather ask a dumb question than get a dumb result

 

Volt meter is easy find a fuse that is hot only when the key is in the engine is run position. Run a "tap a fuse" from that fuse to the gauge positive or red wire if it has one or find a wire close to your gauge that is hot only in the run position and splice into that wire. The black or -neg side of the gauge to ground.

 

Ok....I got all the wiring in today, but I'm still confused as hell for some unknown reason. When I read your post above, I took it to mean that I needed to run a wire from the dumbed down side of the resistor, to the ignition, then back to the coil. My understanding was that when the key was turned ON, then that would complete the circuit sending power to the coil, turn the key again, it fires the starter/cranks the engine then goes back to the ON position. Then, when I turn the key to OFF, it kills all power. When I did that, I *definitely* did not have the desired result. I couldn't turn the engine off...but foreseeing this as a possibility, I put an "OH SH*T" alligator clamp going to the positive side of the coil, from the key switch, so that I could just yank it and kill the whole thing. I'm definitely missing something here......

There's a diagram of what I did pictured below. I couldn't even get the engine to turn over without the wire marked "C". A and B represent the circuit from the key switch to the coil. I used a voltmeter to check which ones would complete and kill the circuit between the key OFF and key ON. It showed that it was the START and BAT terminals. Tried that, wouldn't continue to turn over after IGN was released. I believe I tried b/t IGN and BAT to no avail....I know I tried both on BAT, got the constant running. Like I said....so durn confused at this point. I feel like I've got way too many wires going to the key switch.....

 

No, the "hot lead" for the ignition should come form the key switch "ign" terminal to the "hot" side of the ballast resistor (you have that drawn correctly). Then from the "dumbed" side to coil + (splice A and B together). Choke wire can come off the resistor hot terminal to save some wire length.

 

Looking at the above diagram - Take the "C" wire off completely. Tie the wires marked "A" and "B" together (just splice them together, don't connect them to the switch).

This is what should happen (you can verify this with a test light). When the key is turned to the "start" position power is sent to the solonoid "S" terminal which engages the starter. While the starter motor is turning, power is sent from the solonoid "R" directly to the coil, giving it a full 12 volts for starting. Once the engine fires and the key is returned to the "ON" position, the solonoid releases, cutting power off the "R" terminal and the distributor now gets it's power from the IGN terminal, through the resistor.

Edit: I'm a slow typer, I'm saying what exwestracer is saying, only different words.

 

OOOOOOHHHHHHH!!! Ok, the whole function of the Starter in this equation is part of what was eluding me...how it relates to the set-up as a whole. Sorry I'm being so dunderheaded about this. First time around with doing electrical of any kind on a car....that and I'm a visual person. Below is an updated diagram based on ya'll's mods, along with a "?" mark where I'm not sure if they're indicating a jump from the terminal on the junction block where the wire directly from the battery and the wire to the hot on the alternator meet, THEN HOPPING TO the terminal on the opposite side where the "3" wire from the regulator meets with the wire going to the BAT side of the switch.

 

The junction block is just a spot where multiple wires are connected with ring terminals. You may not have one. Consider all wires as continuing right across the block...

 

Yeah, some cars just have splices to put different wires together, no junction block. A junction block is handy since you can take them off one at a time and easily re-attach them.

 

Yeah, I don't think mine is a junction block in the sense that the current is shared by all terminals. It's actually the one that's pictured below, AND it's labelled "junction block" on the package, go figure. So that means I need to splice from one side to the other as I mentioned in my last post, correct?

http://www.hardwarestore.com/media/product/654768_front200.jpg

 

Just hook up the hot lead from the "ign" pole on the ignition switch to one side, and the wire to the ballast resistor to the opposite side straight across from it. You can hook the choke wire up on the same screw as the wire to the ballast resistor

 

Just hook up the hot lead from the "ign" pole on the ignition switch to one side

So put a new wire from the IGN to one side of an empty bay on the "junction block" that I've got (even though it's not really a junction block in the sense you were talking about) ?

and the wire to the ballast resistor to the opposite side straight across from it.

And put a wire between the non-dumbed down side of the ballast resistor and end it right across from the wire run from the IGN at the "junction block"?

You can hook the choke wire up on the same screw as the wire to the ballast resistor

I'm not sure I understand what you mean by a choke wire. If I'm reading it right, you're saying to go from the place on the junction block I mentioned above, from the resistor side...but I'm not sure where you're saying it should go....

Again...sorry for the confusion. Seeing this is my first time, and I'm a visual person, text doesn't work so well for me

 

Yes, yes, and:

I'm not sure I understand what you mean by a choke wire. If I'm reading it right, you're saying to go from the place on the junction block I mentioned above, from the resistor side...but I'm not sure where you're saying it should go....

On your diagram, you have drawn in a hot lead going from the hot side of the ballast resistor to the electric choke ("choke wire"). This CAN be installed on the "junction block that isn't..." on the same screw as the wire to the ballast resistor. It doesn't have to go there, it just may be more convenient than trying to attach it to the slide terminal on the resistor itself. Electrically it makes no difference which spot you wire it to...

Oh yeah, don't forget to run a wire from the BIG terminal on the starter (where the + batt. cable hooks on) to the "BAT" terminal on your ignition switch. Should be 10ga wire (The right ring terminal to hook that to the starter may be hard to find). I'm not assuming anything anymore...lol.

 

Is it me or is the diagram starting to look like a really bad hand drawn map that gets you lost.

 

If you have a more modern coil that was made for 12-volt, (usually has 12-volt printed on it somewhere) you won't even need the ballast resistor since it is built in to this type of coil. Also, any electrical component (electric carb choke set up) that is not on a fused circuit can potentially burn a wire if shorted to ground for some reason. If this is a temporary system then no problem, just don't forget to unhook the battery when you are through running it. You never know what can happen when you are not around.

 

It's just you. Try reading the manufacturer's diagrams, they're a real cluster F. You're more than welcome to clear mine up and repost...help a man out.

 

It's temporary until I get my Rebel kit imstalled. It's still knowledge that I'll carry over when I do get around to it.

 

In the middle of trying to get a plow truck running that somebody did some custom wiring on , so i feel your pain. Wires aren't suppose to change color every foot and a half are they?

 

That's what the old 6v wiring on mine looked like in places, in addition to ALL being the same color OVEN wire My problem is that I'm also trying to not only see where the wires need to be hooked up, but also understand the flow of charge through each component, and what exactly is happening.