Ignition Wiring/Starting

Cougar Community Classic Cougar Maintenance Restoration and Repair
1

I’ve got my engine ready to run, 1970 Cougar with a 351C and an AOD swap, MSD Distributor and Flamethrower 2 Coil, and I went to crank it over and it wouldn’t even crank. The interior lights light up if the door is open, and the headlights and turn signals work, so I know I have some power, however I am assuming the wire to the S post on the solenoid is bad. A friend helped me mess around and we jumped the Battery side of the solenoid to the S terminal and the starter turned over, and then found out we had no spark, and I checked and had no power at the coil, so we ran a wire straight from the I terminal to the coil+ instead of using the brown wire, and we got it to backfire since the timing is off.

At this point I assume the Red/Blue wire to the S post is bad, as the solenoid wouldn’t even click in the start position, but I was wondering if that could also be the nss wiring? I crimped new wires a while ago to all the wires coming out of the firewall, I’m going to go back and solder them all now, since I figure some of my problem could be the crimps.

So for cranking, it’s either the S post red/blue wire, or the NSS wiring, is there anything else that could cause that?

For powering the Coil, The brown wire didn’t seem to provide power while cranking so I assume that’s bad, and the pink wire is bypassed while cranking correct? I also took out the pink resistor wire and replaced it with a regular wire since the coil is not stock, so is the brown wire redundant in this current configuration?

I have my electric fan hooked up to the coil+ and when I wired the I post to the coil+ and put the key on IGN, my fan came on intermittently. I thought the I post only helped during cranking to provide 12 volts, but it was powering the fan in just the IGN, so is the I post on during IGN as well?

I’ve got a multimeter, I just need some help to know what spots should have what readings when cranking and at IGN, so that I can troubleshoot what is a bad connection or crimp. When the car ran last (3 years ago) I had no problem starting it, at least not electrically, and every wire is hooked up back to where it was before so I assume it’s just the wire splices that are bad, which I’ll be soldering soon. Thanks for any help or advice.

2

Brown wire is not redundant: it is the path from the I point on the starter solenoid to the coil when cranking. When cranking, the voltage is too low via the starter so the coil needs that extra oomph. Nothing else should be attached to that brown wire except the wire you used to replace the pink resistor wire.

The fan should be attached to the ACC or BAT circuit, not the ignition circuitry. The fan requires lots of amperage, more than the ignition circuitry can supply. BTW, the ignition circuit should be only hot when the key is in CRANK or RUN positions.

I am going out on a limb and say you have an automatic transmission. The NSS circuit may be out of alignment which is why the engine won’t crank when the key is in the CRANK position. Or…you could have a bad starter switch. The red/blue wire will only be hot when the key is in the CRANK position.

Do you have a factory tach dash? The tach needs to be connected for the engine to run when the key is in the RUN position.

3

Ok, I’ll leave the brown wire or check it with the meter to see if it’s working, I have the original connector with the 3 pins, for the pink wire, temp sender, and oil pressure sender, I know the brown wire feed into there as well, I’d like to get rid of that connector since the splices and wires on it are damaged, how would I go about doing that?

I’ve got the fan there just for now, most of the wiring is temporary right now just to move the car around. I believe my ignition circuit is only hot when it’s in CRANK and RUN, as far as I’ve seen and tested that’s not been an issue.

I do have an automatic, swapped in AOD. I messed with shifter linkage, so I’ll check if it’s out of alignment. The Red/Blue Wire wasn’t hot when I was in the crank position, I’ll check the NSS and then I’ll see if the crimp on that wire is bad.

I don’t have a tach in there, so luckily I won’t have to dig in the dash.

Thanks for the reply, electrical isn’t my specialty and I’ve never had to troubleshoot and dig to find the problem so I’m sure I’ll have a few more questions as I go along.

4

Checked it again tonight, my NSS has continuity and I fully adjusted it back, however it was basically there already, so now I know it’s my connection to the new wire from the NSS, as the wire after the connector had 0 Voltage

I removed the fan from the Coil+ and found out why it would turn on and off so sporadically, I checked the pink wire with the multimeter and it was jumping from nothing to at most 3V in the RUN position. I couldn’t get the multimeter to settle since it jumped so much, and I tried multiple different ground locations.

The only aftermarket wiring I have is to the fan, and the MSD Distributor, and the fan just has 2 relays, so 2 wires to BAT+, 1 wire to 12V IGN Switch, 1 Wire to the AC Trinary, and a ground. The MSD has the red to Coil+, Orange to Coil-, Black to ground, and a grey tach wire that’s not hooked up.
Other than that I am pretty much stock and wired the exact same as the 1970 Cougar Wiring Diagram says to, there are 2 wires I was unsure of but I believe they were unhooked before. One was blue with a single bullet connector, that goes to a red/yellow, and one was green, with a single bullet connector, that then goes to black. I couldn’t find these anywhere in the diagram, but I’m fairly certain the Green wire to black wire goes to the AC compressor.

At this point my main concern is the pink wire, would that just be a poor connection? And from my previous post, is there anyway to bypass/remove that 3 bullet pin connector for the Temp/Oil/Coil+ wires?

I’ve got the car going to an exhaust shop to get an H-pipe in it, but after I’ve got it back over the long weekend I’d like to get it to start and at least idle, so any advice would be appreciated, thanks.

5

Can’t help you once you use MSD stuff. Sorry.

6

That’s unfortunate, but thank you very much for the previous reply. I’ll be picking up the car from the exhaust shop tomorrow, so she’ll be all ready to run once I can get the wiring sorted out. I’ll be testing and soldering the wire from the NSS to the S post on the solenoid, and I’ll see if I can figure out the fluctuating voltage from the pink wire, perhaps I spliced it in the wrong spot. I’ll update here in case I run into any other issues. Thanks.

7

The MSD is easy to connect.

Big red MSD wire hooks directly to 12 volts at the starter solenoid battery terminal.
Small red MSD wire connects to the resistance wire, ie the original wire connected to coil + side. (Any signal from 5V - 18V will work, this is a switch).
The small black MSD wire connects to ground.
The MSD distributor plugs in to the MSD box.
If its a 6AL you need an RPM chip installed or it will be limited to 1500 RPM.


8

I’ve actually got one of the “Ready To Run” models, so the ignition is done all in the distributor. From its diagram it says Red to Coil+, Orange to Coil- , black to ground, and grey is for a tach. I don’t have a stock tach, perhaps I’ll hook up an after market one after at some point.

I think I’ll have to splice that pink wire again, I believe its spliced at the firewall and after some reading I need to find a better spot for it. If anyone happens to know the routing of that pink wire before it becomes a resistance wire I’d appreciate it, I know it runs from ignition switch to the connector by the steering column but after that I am unsure.

I also realized I wasn’t thinking right earlier when I said I had the fan on the Coil+, that wire is just a trigger for the relay because it gets power straight from the battery. Is that still fine to use or would there be a better spot?

9

The MSD instructions say the only wire to the coil + side is the ORANGE wire from the MSD box.
The only wire to the coil - is the small black wire from the MSD box.

The small red wire from the MSD box connects to the original coil + wire i.e. the “resistance” wire. It is a switch so it cares not if a resistor is in the circuit or not. It operates on anything from 5VDC to 18VDC. It simply turns on the ignition. Best to not modify this circuit or you will simply cause problems for yourself and any future owners.

Regardless of what color wires are coming from the distributor they need to be connected to the MSD Magnetic Pickup circuit (Violet
and Green wires). In the case of a magnetic distributor pickup the white wire is unused from the MSD box.

If this were a Pertronix or point distributor then the wires would connect white to distributor and the other wires as above. In this case the purple and green wires are unused.

From your description you need to revisit the instructions:

10

Oh wait a second - you have the MSD ready to run distributor? In that case the resistance wire will need to be deleted in the circuit. It splices to the red wire from the ignition switch very close to the switch.

11

Yes its the ready to run distributor, and I’ve got the red going to the coil+ right now, however I’m thinking I spliced the pink wire wrong so I’ll be going in and pulling it from the source or wherever the resistance wire stops.

Since I’ll be doing this, I asked in a previous post if it was possible to bypass the flat 3 pin connector, I’d rather just have wires there since my connector is not in great shape. Would I just solder the brown wire into the pink wire? Or do I need a certain connector?

Also just for curiosity, I know the brown wire to the I post gets the same voltage as the pink in the RUN position since they are wired together, would wiring the trigger wire for the fan relay to the I post be essentially the same as having it on the coil+ , or is there a separate reason to have nothing else on the I post?

12

The brown wire on the I post is there only to provide power to the + side of the coil ONLY when the starter motor is engaged. It essentially feeds back to the end of the pink resistor wire and then on to the coil. When the starter motor is not engaged, there is a signal there but it doesn’t do anything because the starter solenoid is designed to only feed voltage to that line only when cranking. Otherwise, the voltage just sits there doing nothing at all.

13

Ok, well if that voltage is there doing nothing when its in the RUN position would that be an okay spot for my fan relay trigger? I would think its essentially the same as it being on the coil+ , but electrical is not my strong suit.

And since the brown wire just feeds into the pink wire at that connector could I just splice it into the pink there and not use the flat 3 pin connector?

14

I would not recommend attaching anything to the brown wire, as it will increase the load on the ignition circuitry, and lower the voltage at the coil.

As far as a fan relay trigger, you really need a temperature-sensitive trigger for that, with main power supplied by the battery. No sense having your fan on when it isn’t needed.

15

There is a wire at the voltage regulator that is switched by the key that is hot in the run position.

16

I’ll check the voltage regulator for that wire then, I need to check it to make sure it works anyway, is there a chart or is it written anywhere what the voltage should be at each pin?

The dual fan I’ve got is from WCCC, its the Old Air Products 50-5067 and it has a temperature control switch however I’ve lost the diagram/instructions and I can’t remember if works for both fans or just the second. I emailed them and I’m sure after this weekend they’ll get back to me about getting a copy so I can set the temperature. Thanks.

17

So I checked some continuity and voltage measurements, and I had full continuity through my starter wiring, from ignition switch to solenoid, which I still couldn’t figure out why it wouldn’t crank, and then magically after disconnecting and reconnecting the 4 pin connector to the NSS, it decided to crank. So now I’ve got an intermittent problem that I assume has something to do with those connections.

As for the Coil power, I had no continuity from the flat 3 pin connector to my coil, and no voltage in the RUN position on the pink wire at the firewall where it was spliced, but I do have continuity on the pins at the ignition switch connector. The only spot where I spliced on there was at the firewall, so that means with the fully stock wiring under the dash I have no voltage in RUN, so it looks like I’ll be removing my dash to get under there and remove the resistance wire and make sure I can get power.

Before I remove my dash, I was wondering if I could just splice at the ignition connector. From the Ignition switch, I’ve got the pink wire that runs alongside the yellow Batt+ wire, then the other side of the connector has a Green wire that runs up around my gauges it looks like. Would I be able to splice at that green wire and just go out the firewall, or does it connect to something else before becoming the pink resistance wire? I know on stock tach vehicles it connects to the tach and the “16A” pink resistance wire comes out of the tach from there, so with no tach, are those just spliced together on my car? I’d like to avoid removing the dash if I can, but if need be I’ve got the time right now.

On a side note, I was checking the continuity of all the pins of the ignition switch, and at every position all of the pins that should have continuity were good, except in the ACC position, there was no continuity from A to B (ACCY to BATT+). In other positions that have power there, it was fine, just the ACC position. Is that an issue with contacts in my ignition switch? I considered replacing it since I read on another thread that the contacts inside are meant for 8 amps max if I remember correctly, and having a 12v coil with higher output places too many amps and burns up the contacts.

18

Well I completely removed my upper dash, gauges and all that, and finally got a good look underneath. It seemed 90% untouched, maybe someone had been there but hadn’t messed with much.

I did notice that there was a black wire that was just wrapped around and within the tape, but I saw on a post from Midlife on another topic that the wire is meant to be disconnected and helps another wire clamp on essentially. I did also notice that my seat belt warning light connector was just lying there, and I was unsure if it was disconnected for a reason, or had come off somehow, but I haven’t put anything back on yet so I’ll mess with it soon.

I ended up pulling the resistance wire all the way through the firewall, up around the steering column, and all the way down to the fuse panel, connected in tandem with a red and yellow wire to a 14A fuse I believe. I tested the continuity of that red and yellow and found it went to the seat belt warning connector, and after ignoring it and hooking things up wrong, I realized that the ignition wire (Green) goes up to the seat belt warning connector, meets with that red and yellow wire and then goes to the fuse panel where it meets with the pink resistance wire. So I ended up running the new wire from that spot on the fuse panel through the firewall and in the RUN position I have 12V.

I hadn’t seen anywhere on any of the diagrams I have that the ignition runs through the seat belt warning, and I was wondering if this was the usual for non-tach cougars.

19

Ignition doesn’t run THROUGH the seat belt reminder light, it simply provides power to one side of the bulb and only when the key is in RUN position (makes sense…seat belts are needed when the engine is running, no?). The RUN-only line powers up the ignition wiring but also other things unrelated to ignition.

20

Yes I understand how it works, it makes sense I was just confused at the diagrams never showing the wire making that stop at the warning light.

Well I’ve cleared up a lot of the issues, now I just have to figure out the lack of continuity in the ACC position but that’ll be for another time. Thanks for everybody’s help on this.