Changed Wiring and Problems Running Now

[MadMax]

Happy Thanksgiving, all!

I’ve got a 15 Touring car and decided to replaced the wiring harness and spark plug wires. The existing wires were from ~1977 when my father did a complete tear down restore. The car ran fine before.

What I did: I replaced the wiring harness, spark plug wires, and the wire to the mag post. I have yet to replace the wires between the headlights and from the port-side headlight to the body. I have yet to change a couple other wires (battery to the box, headlight switch to the box..). I disconnected the timer to get the wires on. I’ve done this before to clean the timer cover before. I did not touch the fuel system at all.

What’s happening now: when I drive it, it appears to lose power and start to bog down. The spark advance definitely has a different feel (likely from the different wire attachment; I tried mimicking the previous arrangement). I am getting some minor backfiring as well. The coil clicking/firing sounds about the same when running on battery (which is quite a bit different than before the change). Prior to the change, the clicking was fairly quiet after switching to running on mag from battery. I’m not sure whether this louder clicking is a good thing or a bad thing. The car started without a problem.

Other “issues” - the wiring change appears to have solved a problem where the headlight switch was electrically ‘hot’ (so that’s a positive). The linkage to the timer (at the base of the steering column) is and always has been really sloppy. I have a feeling this may have something to do with the change in performance, but I didn’t play with the linkage... *other than* the difference in the wiring at the timer which has changed the action of the timer movement a tad (likely from the wiring not having ‘broken in’).

Remember that the car ran fine prior to the change. I’m likely going to add a follow up question/statement on an observation, but I’ve already written a novel. I also don’t want to ‘poison the well’ by suggesting something.

I may try to post photos, but I need to read up on how to do it.

Thoughts? Thanks in advanced for any input!

[Ruxstel24]

I would start by checking all the connections from the new harness, especially the power and ground at the coil box.
What kind of condition is your coil box in ?

[Charlie B in N.J.]

"Ran fine before the wiring change". Now what, if any thing, could cause poor performance/backfiring after the change. If the wiring was correctly done probably nothing in itself. Perhaps the switches and terminals are better suspects. You mentioned a hot ignition switch. The fact that it's not getting hot now doesn't mean it's not damaged. Power going on and off will cause backfiring. It's something to think about. How about "hot wiring" the coil box and going for a ride ? If there's a difference could lead to the culprit. I'd disconnect the mag wire if you do this just to be safe.

[Norman Kling]

Here is what I would check first. Put the spark lever all the way up and turn on the ignition switch to battery. Turn the crank very slowly till you get a spark at number one. Then turn again one half turn until you get a spark at number 2. Then turn again one half turn till you get a spark at number 4. And lastly turn again one half turn till you get a spark on number 3. The sparks should come in that order and one half turn apart. If the order is wrong, you have a couple wires at the timer in the wrong position.
Norm

[John kuehn]

When you replaced the wiring harness’s to the coil box and timer did you use the color code as your guide OR go from terminal to terminal regardless of the color on the wire or the tracer.

[Steve Jelf]

I would assume the new wiring has the correct colors (mine did), but some of the older reproductions didn't. If you want to check your timer connections you can use this.

TIMER.jpg (63.67 KiB) Viewed 9213 times

[MadMax]

Many thanks for the comments so far!!! I’m going to try to reply to each:

Ruxtel24: I like this suggestion a lot! I can specifically remember making sure each of the nuts for the timing wires at the coil box were tight as well as the nuts for the spark plugs at both end, but I can’t say I definitely tightened the nuts for the mag and battery. I’m pretty certain that the nut on the mag post was tight as well… I’m with family for Thanksgiving and can’t check it just now. That will be “simple fix #1” when I get home.

Charlie: You are going in the direction that has raised an eyebrow from mean the past with the ignition switch. One clarification though. The hot switch was the headlight switch (that hurt!). My headlights were always on for that reason. That issue went away. I have had the ignition switch/key hot hot on me once (grabbing the spark advance and switching to mag… hellooooo!).

With that said, Charlie, I had an issue the first drive out where it lost power and I could hear the coils just buzzing away… this is something I know how to deal with… one of the screws that holds the ignition switch box unscrews from the nut, falls to the bottom of the ignition switch box, and shorts the connections. The second problem with that is that the nut always falls into a gap at the bottom of the coil box and is a bear to get out. I bring this up because after it was fixed, I noticed that the one wire (red) that crosses through that same gap) had the insulation nicked and bare wire is seen. Could this be an issue? I can post a picture of that as well.

Norman, John, Steve: I will definitely check the firing order as well. Am I imagining things or would the car react.. ‘Harshly’ to this… hahaha… and wouldn’t the engine consistently sputter heavily and backfire? I’m going to post pictures that show the connections at the coil box as well as shots of the timer sitting in-place. I followed the order in the diagram a Steve posted (thanks, Steve!). I’m pretty sure I’ve got that right… but I’m fairly new and have done some pretty stupid things in the past so all bets are off on me using common sense! Hahaha.

To all:

Side comment: when removing the nut on the mag post, both the nut over the wire and the nut under the wire rotated. I am hoping this isn’t an issue.

Another side comment: as noted, the issue with the hot headlight switch has gone away… is there a possibility that the shorted wire could have tapped power from the mag and now I’m just hearing the coils firing better as a result? I’m skeptical of my theory (maybe wishful thinking?).

Now let me see if I can get a couple pictures up…

[MadMax]

Here are those photos...

Not sure why they are rotated, but if you click on them, they will show correctly.

That last one is showing the wiring coming through the coil box and a nick from the insulation at the penetration.

[John kuehn]

You may have already checked this out but make sure the timer case terminal wires are not touching the block or when the timer is advanced they are hitting the spark advance rod.
If the car was running pretty good and wasn’t really missing bad it would seem that when you changed the wiring something is getting grounded or not making a good connection. Or so it would seem but not always true. Good luck!

[MadMax]

Great suggestion as well, John. Thanks!

I think I should make up a grid like a football game pool and put everyone’s name on there. The person in the right square gets a prize! Hahaha

[Steve Jelf]

You should not get a shock from any switch, no matter what else you're touching. Look inside your ignition switch and be sure all wires are where they should be and are properly insulated. There should be no path for current to reach the key. While you're in there make sure the metal tabs are tight enough to make solid contact.

Sometimes insulation inside the switch is deteriorated and needs to be replaced.

Thick gasket paper is good for insulation behind the switch.

To install new insulation you will have to remove the old rivets. You can replace them with pop rivets tapped to hold the terminal screws.

The rivets need to be insulated so as to not touch the backing plate. Nylon washers will work for that. The rivets should be mashed flat enough to keep them from touching the coil box.

[MadMax]

One bright spot is that I’m not getting zapped by anything (and the headlights are still working).

Here is my ignition switch box and a couple notes:

If there was a short in that red wire (in the bottom of the box), wouldn’t I show power somewhere (like the coil box might be ‘hot’)?

Something else I’m thankful for... the quality of the cameras in cell phones nowadays!!

[Ruxstel24]

The stud in between the terminals looks kinda questionable to me.

You can do a voltage drop test there, check voltage at the wire and then on the stud and terminal. Or you can wire a 12V headlight bulb and check the same way, that will put a load on it...

[hah]

OT .... does the timing rod require a cotter pin?

[MadMax]

Ruxtel24, I’ll definitely check that! Was working fine before the wire change, but you never can tell!

Hah —>. Great observation! Luckily, I noticed that and put the pin back in! Great catch!!!

[Altair]

Your issue seems more like fuel than electric, either you have power or you don't, bogging down and backfiring does appear to be fuel related.

[MadMax]

I’d jump at that, but the car was running fine before the change (within days) and wasn’t afterwards. The fuel system wasn’t touched.

I’ll definitely add this to my list things to check! Thanks for your suggestion!

[Altair]

This time of the year a little water in the gas could be ice the next day.

[MadMax]

A little further into the winter could be an issue, but I’m in coastal Virginia. So far, no freezing.

I’m definitely looking fuel related issues as we’ve had a season change and it hit me that it can be temperamental switching between the hot and humid over to cooler and drier.

[MadMax]

Okay, I officially got back from my vacation at 9 and gave a couple tries from the various suggestions made both here and suggestions made by friends at my local chapter.

I’m pretty sure I eliminated fuel related issues... and just for S&G, I made sure the car had gas in the tank. It did.

The firing order appears to be correct. The timer arm wasn’t making contact with the timer terminals.

Here’s the creepy part... when I went to start the car on battery, the coils were firing... ALL the time and not just when the the engine was rotated to the specific coil. And they were buzzing a LOT (seemed to be more than normal). I double checked and set the ignition switch to battery, then slowly rotated the crank through two complete rotations. The coils buzzed continuously and never stopped at any position in the rotation.

I also put the ignition to mag and did the same. The coils never buzzed as I rotated slowly through two rotations. At least I know that isn’t the issue.

This tells me I have a pretty bad short, but not sure where just yet. I’m going to investigate more tomorrow again.

Steve, I’m thinking your thoughts on the ignition switch are the winner here. Looking back on that picture of the wire at the bottom of the coil box that had some of the insulation off, could this be the short?

Any thoughts?

I’m going to try checking voltage at different points tomorrow as it’s getting late. Thanks for any thing you may have in mind.

[Steve Jelf]

You wouldn't get the continuous buzz on magneto because it's not turning fast enough to supply enough current. You may be hearing that continuous buzz from just one coil. That can be caused by the top timer terminal screw grounding against the timer control rod.

[MadMax]

Thanks for the reply, Steve. I will check this afternoon after work. I checked it last night as it was one of my 'easy' checks. I just need to make sure I check it correctly this time. ha ha ha. I'm pretty sure they were buzzing even when I advanced the spark and the top terminal wasn't making contact or even close. It never hurts to recheck!

It definitely wasn't an issue of the mag because the car was off when I tested the mag (just to see if there was a short that was putting power through while the ignition was turned to mag). I did this because it sounded like the coils were buzzing while the car was up and running and driving on mag (the coils sounded like it/they would when getting ready to crank start and a coil was aligned so that one of the coils was active). If that makes sense

I'm really worried about that one wire (I mentioned previously) that runs through the bottom of the coil box that has damaged jacketing/insulation. That and your (Steve's) suggestion of damaged insulation in the ignition switch box. I'm likely going to be buying a new one as I need the car up and running for two Christmas parades this weekend.

[DanTreace]

Max

Seems if wiring changes caused issues, would really look close at the timer wiring again. Those 'flag' style terminal have longer side with the solder wire point. Those flag ends can contact metal of the front plate, bolts, or timer rod. If any contact, a coil wired to that flag will fire. You only want contact of the coil wire to the rotor inside the timer case.

IMO, this is the issue, note your terminal can hit the metal front plate, and the timer rod. That rod does need a cotter, or else it will fall out or back off and contact the terminal, causing the coil to fire. See arrow, plus another flag terminal on the lower side of your timer case is positioned this same incorrect way.

Make those flag terminal all around the timer case look like this:

IMG_4835.JPG (95.41 KiB) Viewed 8712 times

Or if you place the flag to the rear, a pair of needle-nose pliers can be used to 'bend' the flag up, to make sure in no way can the terminal contact any metal. And be sure to keep the timer rod secure, so it won't flop and contact anything too.

IMG_8293 (550x413).jpg (140.99 KiB) Viewed 8712 times

[DanTreace]

Forgot to mention, for the very neatest appearance and protection of shorts to the wire there, Ford made this fabric like 'retainer' P/N 5033B ('21-'27) to fit on the timer case under those flag terminals. Lang's makes a repro today. Haven't ever placed one of these, nor seen an original on a T, but these were used. Might be bit harder to install, but sure looks good and should work well. Ford wouldn't have spent pennies on it if it didn't

[MadMax]

Hey Dan! Thanks for the suggestion and I'm hoping this is our turkey! I took a couple more photos and I see what you mean. That blue terminal needs to be flipped and rotated 90 degrees counterclockwise! I took a couple more pictures and it seems to be pretty close to touching (if not touching). I was trying to keep it out of the way of the timer rod and instead backed it up against the front plate. This is a picture I took of the old wiring and I can see that it was rotated on the old wiring arrangement.

As far as the bottom terminal that was incorrectly set, I just followed the top one... mostly because the old bottom flag had broken off and I had it temporarily just wrapped around the post and screwed down (in that case, there was hardly any copper left to stay connected!). YOu can see that as well.

I'm feeling pretty confident right now, but I don't want to get my hopes up too high just yet.

I'll let you know. Thanks again!

[MadMax]

And the winner issssssss:

Dan Treace!!!! You hit the problem on the nose. The wires were shorting out against that front plate. I rotated that bottom one. The top one in the photos got bent upward to prevent contact with that front plate or the timer rod.

Many thanks to all of you who had input! Greatly appreciated.

I will still actually be looking over some of the things folks brought up as I think they will help tuning the car better.

Max

[Ruxstel24]

Good Deal !!
Glad it was relatively simple.