So I changed out my cab within the last few days for a newer and less rusty cab.

Everything on my old cab worked just fine, and all the possible wires were hooked up. Everything on the new cab is hooked up and I've triple checked everything to make sure it's connected and connected correctly.

Nothing has changed from old cab to new cab, just the wiring harness from the new cab is being used.

I was just outside with the truck, had a friend ground out a spark plug that we took out of the block AND THERE IS NO SPARK WHEN I TURN IT OVER!

WDF? How come I have no spark?

I need some help!!!

Here is a pic of what I think might be the problem...


The red/pink wire connected to whatever this do-hicky (can't remember the name of it) is called, is on the negative side (shown by an "N"). The brown wire (which I think is the negative wire) is connected to the positive side (shown by a "P").

When I had the wires connected (brown to N, red/pink to P), the truck was lifeless... When I connect the brown to P and red/pink to N, the truck has life, BUT NO SPARK!

My spark plugs are fine, but I can't figure out the problem! Here is a pic!

 

Bumpity bump bump...

 

Are you getting voltage to the coil? Either the + (pos) from the ignition or a blinking light/ DMM off the - (neg) terminal?

Josh

 

I'm not sure. There are no blinking lights on my ignition coil at all. There is nothing there to indicate that I have any power to anything.

I'm guessing that what I need to do is break out my multimeter and start testing stuff when the key is turned over?

Edit: how the heck would I test that? Both ends of the multimeter to one side of the coil?

 

Multimeter black to ground and red/positive to the + of the coil with "key-on" Do you have power?

If Yes... then connect the DMM + to the NEG of the coil and crank the engine. The meter should indicate a power pulse.

If No... the dizzy pick-up or module is suspect.

Josh

 

Okay, so it turns out that with my new wiring from the new cab, there is no "on" position anymore. As soon as the key hits where the "on" position should be, it wants to turn over. AKA, I don't need to twist the key the whole way to get the engine to turn over.

So I tried:
with the ground being the engine, and the positive on the positive side of the coil. There is no power....

Just for ****s and giggles, I tried the crank the engine with the DMM + on the - side of the coil and the DMM - grounded... nothing either...

So how do we solve this problem? Can I somehow jump my pick-up or module? I need to get my truck mobile tonight or at least tomorrow morning (at the latest).

I've just double-checked all my connections again, and it all appears to be looking good. I'll post up a pic of what it all looks like under the hood in a moment...

 

So here is what I see...

Ignition Coil behind my hand...

(from what I understand about ignition coils..)
Positive side = red
Negative side = green




Red wire going into the distributor... AKA, hacked up farmer job. Was exactly like this before and worked, so I don't see that it would be the problem after only 2 days of the truck not starting...



Another shot of the coil, this time showing the negative side a bit better.



following the wires to the ignition module box on the drivers side inner fender... again, everything hooked up...


Edit: The dizzy's vacuum advance is hooked up, just got rid of it for the photo. Also, I've never had that small AA battery looking thing hooked up before and the engine has fired (can't remember it's name atm... I was holding it in the first photo). Also, the extra wire off of the + side (Red wire) of the coil has never been hooked up also, and everything has worked... Not sure why there are two red wires to the positive side of the coil...

 

What year is the replacement cab from?

Is your neutral safety switch hooked back up?

 

Something is definately getting crossed if it's trying to crank in ON or RUN.

If you really want to to bypass it, and don't do it for long, but use a length of wire from the + of the battery and connect it to the + of the coil.

But I wouldn't do that until you get the ignition sorted as you don't want the engine starting in RUN with the starter still spinning.

Brown wire at the solenoid connects to the "I" terminal and a red/blue connects to the "S" terminal.


Josh

 

Looks like his red/blue wire is pink and it is wanting to crank in the run position because his brown and pink wires need to be swapped. "I think"

 

I saw that too, looks like red/blue going into the connector and a faded pink coming out.

Josh

 

The replacement cab is from 1979. There shouldn't be much of a difference between the two cabs, except the fact that the new cab has A/C, and the wiring is still choppy (needs a Painless kit badly...)... so it doesn't help that some of the A/C wires are running around randomly and loose/not connected to anything. Just makes wiring so much more confusing.

Neutral Safety switch? Never heard of it. What is it?

I had the red (pink in my case) hooked up to the S terminal, and the brown hooked up to the I terminal. I tried reversing the two, and I get absolutely no power to the truck whatsoever.

Also, I got a chance to figure out my ignition coil and all that wiring... I'll post up about it later once I get a picture or two, but for now.. it's figured out.

I tried swapping the brown and pink. When I turn over the ignition in the cab, I get no power to anything in ANY position. This isn't the solution?


So right now, when I turn my truck over with the brown on the "I" terminal and the pink (in my case it's pink) on the "S" terminal... the starter solenoid will not disengage... NOT GOOD NEWS!

How the hell do we solve this puppy? Pictures are on their way within a couple minutes.

EDIT: I doubt this matters, but I'll post it up anyways. I recently removed the starter solenoid to get the VIN # off the engine so that I know what year my windsor is. If I put my starter back on improperly (I doubt I did, but it's possible), would that be causing this issue?

It seems more electrical/crossing wires to me, but it's just a thought.

EDIT #2: Also, because I'm using my original trucks ignition (because I only have one set of keys), and my new cabs wiring, would this make a difference in the way that the ignition runs all-together? I might just be stabbing in the dark here, but it's good that you guys know wdf I did haha.

 

The Brown wire from the "I" terminal runs full battery power to the coil during crank.

The red/blue on the "S" terminal is what trigger the solenoid.

Neither do not have anything to do with power to the rest of the truck. That is dependent on the big gauge Black/Yellow wire in the harness which needs to be connected to the + lug of the solenoid coming from the battery..

Josh

 

Weird, I thought that everything was somehow connected. Anywho, how in the heck do we solve this problem?

I don't think I'll run my truck at all if the solenoid on the start will not disengage... not a good idea... That, and I can't stand the noise it makes when it doesn't turn off. Sounds like a really really really bad exhaust system...

 

Using a 79 Cab is a good thing, you are correct, pretty much the same wiring.

Neutral Safety Switch is the piece that make it so your truck will not start in gear and if not properly hoocked up or adjusted, it causes all kinds of starting problems. There should be a grey plastic 4-pin male connector somewhere around the passenger side valve cover, up on the firewall or hanging down. I believe that is where the NSS hooks up (at least it is on my 78 cab). If it is not hooked to anything (if it is plugged in, unplug it and try the following as a test), make a temp jumper wire to connect the two pins that have the blue w/ red tracer wires attached. That will complete the circuit between the ignition switch and starter solenoid. Be careful not to hit the key while it's in gear because it will try to start.

The reason why the starter engaged when the brown wire was attached to the "S" Terminal is because it is getting power in the "Run" position of the ignition switch for the ignition system. Without a multi-meter this is a good way to test that wire.

Hope all this helps. Good luck.