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Ignition switch / starter wiring issue

52K views 46 replies 5 participants last post by  walkerjay 
#1 · (Edited)
Fired up my motor! Runs like a champ. Have an issue when I turn the key. Not getting good spark. Checked with meter. Volts to Big Al's coil wire is low.

I noticed when I was wiring up the car that my ignition switch harnesses did not match up with the diagram completely. I'm pasting what I have below. If anyone happens to see something that catches your eye, please let me know.

My starter currently has only the purple starter wire going to it. I don't see any reason to use the R terminal with my HEI setup so not sure if it's starter wiring.

My NSS is wired thru my shifter and is functional. I only get continuity in park or neutral. So far so good.

I'm thinking it's something with the ignition switch. I guess to summarize, I am not getting full 12 volts to the coil power wire. What do you think? Thanks so much.



 
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#2 ·
When you say low voltage, what is low ?.

You may have stacking up voltage drops through connections coming from the battery through the bulkhead connector up to the ignition switch then back out of it and through the bulkhead connector. I have taken a factory ignition switches apart and they do wear out and can have voltage drop issues.

I know it's a bandaid solution but if you have enough volts on the new HEI power wire, you may be able to run this through a relay and get power directly from the battery. Some relays only take an amp or two to trigger and can operate with a low voltage down to something like 8 volts or so.

Try this, get power for the HEI directly from the battery and see what happens. The engine will not shut off with the key but taking power for the HEI away will kill the engine.

When an engine is cranking the voltage will go down but then once it's running the voltage should come back up.


Jim
 
#3 ·
I am guessing that you had a points distrubutor to start with did you replace the resistor wire that was running to your points coil with a new wire the old wire only feeds like 9v that was so it didn`t burn the points up it fed 12v from the wire that was coming from your starter but only during start up then it switched to the constant 9v. You only need the one wire running from the fuse box connector on firewall not from the starter.
 
#5 ·
Original car had points distributor. Yes,I converted to a 12g red wire from bulkhead to coil. Now that should begetting 12volts all the time right? Like in start/run and also during cranking..?

You only need the one wire running from the fuse box connector on firewall not from the starter.

I'm not following you here...? could you please explain?
 
#6 ·
I still think you need to have two wires to the positive side of the coil. So If it,s Gm,s H.E.I you need to group the two circuits. The bulk head wire you change from a resistor wire to a 14 gauge red. A wire from the R terminal of the starter to give you 12 volts when you are cranking it. If you have the new style starter with just the S you can run from that up, it will do the same function,12 volts in crank position. Gary
 
#7 ·
So are you saying I need to get 12 volts to that R terminal on the starter? If so , I wonder why so many guys are telling me, and I also see, that one starter wire is enough....

I already have the 14 gauge red bulkhead wire which replaced the resistor wire. You think I need another wire in this power circuit to the starter "R" terminal?
 
#8 · (Edited)
You should only need one wire.

The stock *points* setup used a resistor wire from the bulkhead connector to feed 10V or so to the points in the 'run' position so the points would arc less, and last longer. There was a second wire from the starter to the points that fed a full 12V *while cranking* to give a hotter spark when you were trying to start the car.

The HEI gives you a nice fat spark all the time, and there's no points to wear out, so it wants a full 12V all the time. Follow Big Al's (nicely done) instructions, replace the resistor wire from the bulkhead connector with regular wire to feed 12V to the HEI in 'start' and 'run' positions, and you're done. You don't need the wire to the starter if you're using HEI. (It won't hurt, but...why do the work if you don't need to?) If there is a wire from the starter, remove it entirely, or make sure it's secured properly so it won't accidentally ground out on something and start a fire.

As stated earlier...check the quality of the connections. The path goes from the battery to the horn relay, then to the bulkhead connector, to a fuse in the fusebox, through the ignition switch, the neutral safety switch, back to the bulkhead connector, and then to the distributor. There's a lot of different connections that can corrode and add resistance.

Also...don't forget that this is a *circuit*, so the return side of the path matters too. The connection from distributor to the engine block to the negative terminal on the battery needs to all be reliable connections too.
 
#11 ·
patman - I have it wired precisely to Big Al's thread. One wire. Prob is I'm getting 12 volts in run but when I start and crank the motor over, it's dropping to 9 volts. When I check spark the old fashioned way (screwdriver in wire boot) the spark is weak.

gary - yes, battery voltage matches up...right around 12.

Here's something else going on....when I turn key to start, volt gauge drops from 12 down to nothing.
 
#13 ·
Added a jumper from coil to R on starter. Diagnostics with meter show a drop to 9 volts when cranking, with R wire on or not.

Also, my volt gauge drops to O upon cranking for start up. Perhaps this is a clue....

some wiring pics...
test setup


starter wired


bh1
Image uploading. Refresh page to view


bh2


battery w/ fusible link wire to junction


who needs a one wire alternator? This does just fine...


reverse light switch works fine. NSS worked ok, now is intermittent so It's bypassed for now


I lost a couple wires from the bulkhead that went to nothing. If anyone sees a major wire missing, please advise. thanks.

Besides Battery to jb, are there any other critical areas that require a fusible link?

My current status is voltage drop to coil during startup.
 
#14 ·
Added a jumper from coil to R on starter. Diagnostics with meter show a drop to 9 volts when cranking, with R wire on or not.
If the extra wire isn't making a difference, the problem is likely elsewhere.

Some thoughts (at this point my money is on #4)

1) You said earlier that at one point you jumpered the HEI directly to the battery temporarily. If you have it fed that way, does it still drop to 9V when cranking? If so, it ain't the ignition wiring.

2) The negative battery cable looks nice, but it appears to be attached to a nicely painted alternator bracket attached to a nicely painted block. Make sure there is a good metal-to-metal connection (no paint!) between the bracket and the cable, and the bracket and the engine block (such as where it attaches to the intake manifold or water pump)

3) The block is grounded to the battery, but what about the rest of the car? Do you have a wire between the battery negative and the body? Do you have the grounding straps installed between the engine and the body?

4) Seems like you've been playing with this starting issue for a while without really having the engine running all that long. The starter draws a LOT of juice from the battery. It could be that the battery is just run down. Try throwing it on a charger to top it off and see if that helps.

5) Is the alternator working properly? You should get 12V at the battery with everything shut off, and 13.5 or so when the engine is running.

HTH...
 
#17 ·
Charging up now.

Will be able to get out there later and was planning to go back to testing some things getting power directly from the charger and bypass the battery. Will also add that extra ground. I have seen in a 68 assembly manual that they run a wire from neg to rad support. Maybe I'll do that...

Thanks again for the guidance.
 
#24 ·
Just for giggles...

Try the same voltage test on your daily driver. Check the battery voltage with it not running, and see what happens when you are cranking, and what it is when it's running. It's not a 100% fair comparison (unless you happen to have another 3rd gen as a DD...) but it will give you some idea of what the numbers are on a correctly operating setup.

I think something around 12, 10, and 14 are the 'right' answers for those three.
 
#27 ·
Charged up battery a bit last night. Went out there today and cranked it with the charger on.

Meter hooked up to coil wire (HEI not plugged in) and I'm only getting 8
volts +/- during cranking.

At this point I am wondering if I do in fact need that R wire from the starter to give me a boost to the coil and perhaps my solenoid is not 100%. Not sure if it makes a difference but that starter and solenoid have been sitting in a box for 17 years since I packed them away brought them out for cleaning up.

I'm stupified.:turn::turn::turn:
 
#29 ·
Thanks again Patman. I think when I kicked the charger on it was higher than 10 amps then after a while it was a bit lower. Shame on me for not keeping better records. It did move some. Boy, that really makes me sound like a dummy!:sleep: 12 volts, half hour first day, half hour second day.

here is some info I found on the web..... for consideration

The following has been pasted from tech#5 hei conversion.
With the ignition ON, but not cranking, you should have within one volt of battery voltage, or a very bright test light. With the engine cranking, you should have a minimum of seven volts on the voltmeter or a medium brightness on the test light. Poor voltage? Repair wiring from ignition switch. If you have good voltage, reconnect power wire.


Had similar problems. I ran a 12 guage wire from the horn relay thru a 30 amp Bosch Relay (6 bucks at Radio Shack) and everything has worked fine. You may have to run a wire from the starter to the relay to make it work. Don't have the smarts to send the diaghram over the net, but if you havent got it cured in a day or so let me know and I can snail mail it to you.


I used an Ohm meter to find a wire coming out of the fuse block, that had 12 volts under cranking. Then I just tapped into that wire. It was a brown one I think?

OK, a very knowledgeable ignition person I know, thagt builds his own HEI conversions, told me this way,

Take a look on the fuse box for a terminal marked either IGN or IGNITION. Then, with a voltmeter set to 20 volts, connect the plus wire from the voltmeter to that terminal on the fuse box, and the minus wire form the meter to a good ground. Then, turn the key to the normal run position, and check the meter, you should have full battery voltage. Next, turn the key to the START position and check for voltage, should be there, but lower. No issue with lower volts on start, the volts get divided between the ignition and starter motor.

If both key positions pass the voltage test, remove both the wires that went to the original coil positive terminal and tape them up, put them into the wiring loom, they won't be used for the HEI.

Then, add a 12 gage wire form that IGN terminal, poke it through the firewall, and connect it to the BATT terminal on the HEI. I have a few vehicles that are wired that way, and no problems/issues in any of them.
 
#31 ·
I think when I kicked the charger on it was higher than 10 amps then after a while it was a bit lower. Shame on me for not keeping better records. It did move some. Boy, that really makes me sound like a dummy!:sleep: 12 volts, half hour first day, half hour second day.
I lost the directions to my charger :mad: but the last couple of times I used it, I set the output to 10a (mine has 1, 10, and 50 amp settings) and left it on for 3-4 hours.

Somebody else check my usage, but...if you can set it for around 10A output, I think you should leave the charger on there for longer...say 2-3 hours or so. (If it's a trickle charger and only puts out 1 amp, it might need to be on even longer than that) Check the instructions for your charger though, I don't take responsibility if something goes boom.

Just for comparison, I pulled up a random set of instructions:

http://www.battery-chargers.com/charging_instructions.htm

...and that says for a 550cca battery (completely dead...which yours isn't) at 10A, it should take 6 hours for a full charge.
 
#32 ·
cool. don't worry, I won't hold you liable for any booms.

I spent an hour and a half pulling everything apart and scoped out each wire, in particular, from behind my fuse box. everything was looking good but towards the end, I noticed a discrepancy between where my orange wire goes to the ignition switch ( per the wiring diagram) and where it actually ties in behind my fuse block. Just came inside....will investigate further tomorrow.

Think a mismatched ignition switch wire could cause trouble? I think its possible.....
 
#34 ·
Here is what I have currently....a bit different than the wiring diagram. I just want to make sure that nothing was hacked up or altered prior to me getting the car. Comments appreciated. I am also going to be looking for some pics of nova ignition switches...for additional reference.



 
#40 ·
I am definitely not talking about the HEI wire. I have a red 14 wire per Big Al taking care of that. I'm talking about the 24 br/w wire labeled RESISTANCE WIRE) IN THIS PIC. I strip the wire sheathing and its a single piece of alum or steel? wire. Per wire diagram, this goes to my ignition switch but where it was originally, was not in the correct (per wire diagram) spot.

I spliced them as a temp setup but plan to redo, connecting them both directly at the terminal.

Thanks for hanging in there. Battery is charging, going to my friends shop to test it.
 
#35 ·
Went home for lunch and tracked down another wire.

Backtracked the brown wire from my external voltage regulator to the bulkhead.

Went inside to the opposite terminal behind the fuse box and found the brown wire. So far, so good.

Trace the brown wire at my interior and its running up to the heater control. :eek:

Wire diagram has it going to light switch!

Everything looks factory. I'll be triple checking and labeling things.

Not sure this is related to my starting voltage issue but I think I may have stumbled upon a potential issue.
 
#36 ·
Ok, here's what I've done so far....

1. I needed to tap in a missing resistance wire from my bulkhead / voltage reg. to the ignition switch. Diagram shows it as 20 DG. So used green wire. :yes: Couldn't solder the resistance wire so I stripped back a portion of brown wire I was tapping into, wound the resistor wire around and it was tight, added some heat shrink. Continuity tests good.

2. My ignition switch had two red power leads coming to it. Factory wire schematic shows only one. I pulled one temporarily.

3. Heater switch checked out ok.

4. For 21 bucks I got a new ignition switch. The new one has an extra tab with a hole. Looks like it wants a ground wire attached so I added one with a screw.

Ran some meter tests. Happy to not see smoke after my wiring alterations. Right now I'm dead on factory diagram. Glad I went thru everything. All numbers look the same. Battery sits at 11.8v. Upon cranking I get 9.2 volts to coil (9.6 with a jumper from the R on the solenoid to the coil. ??? (solenoid issue?)

With the battery charger on I got right to 10 amps. All numbers on the volt meter go up a bit with the charger attached and charging.

so, what do you think?
 
#39 ·
Charging the battery is one likely solution, and it's simple and cheap to try. If it works, great. If not...that's ruled out and you're not out a lot of time or money.

1. I needed to tap in a missing resistance wire from my bulkhead / voltage reg. to the ignition switch. Diagram shows it as 20 DG. So used green wire. :yes: Couldn't solder the resistance wire so I stripped back a portion of brown wire I was tapping into, wound the resistor wire around and it was tight, added some heat shrink. Continuity tests good.
Not loving this part...

AFAIK, the only resistance wire that was there originally went from the bulkhead connector inside the engine compartment, to the distributor. For an HEI, that needs to be replaced with a normal wire.

If you're talking about the wire to the distributor, that's crucial. Soldering would be OK, but not as good. Check out Big Al's directions again, they cover removing the terminal from the connector block. Do that, crimp on a new terminal to the replacement wire, and that will give you a reliable connection. If you're very careful, you can sometimes pry the crimping open and reuse the terminal.

Just wrapping the wires together is NOT sufficient. It might test out OK with the ohmmeter, but under load it won't be able to pass enough current. Think of it this way: If you were connecting two water pipes, and used electrical tape to seal the joint, it would work fine if you poured a cup of water through it, but it wouldn't work so well when you turned the water pressure back on.
 
#38 ·
Thank you very much. Sounds like your sticking with your battery thinking all along. I will definitely charger her up nice. May also swing by my store for a replacement if need be. These things are supposed to be fresh. I have an AC Delco battery 660cca. Been dealing with this auto shop 20+ years. Twice have I taken something back and there's never a question.

Too bad optima's only come in yellow and red.

Q: Do any of my wiring mods make sense or did I mention anything that raises a red flag?

:beer::beer:
 
#41 ·
My friend got 11 volts from his meter. He does not have a charger.

After reading thru Patman's charging link, I am nto going to use my charger. Maybe toss it. It's ancient and has no ground plug. They were very adamant in that charging article about grounding the charger. So.....I'm off to find someone who can juice this thing up...starting with the place I purchased it.

Buddy coming over at 6 to help bleed my brakes. beautiful day. Hopefully she'll be purring later this eve.
 
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