Hi all,

I recently purchased a '66 Coupe. All things considered, the car is in good shape. The interior is pretty nice, the engine is in decent shape with about 30k give or take miles on it, etc.

The one thing that I am having problems with is some of the electrical. For example, when I apply the brake the park lights on the front light up. When I turn on the lights, only one of the head lights works on low beam and both work on high beam.

Basically, I am going to buy the harnesses and start rewiring the car. I was tracing some wires from the head lights this weekend and noticed the wires are old and brittle (sp?) and just generally weathered.

One problem I have is that I only currently have one cheap plastic horn on the car that doesn't work. It is my understanding that a '66 should have two horns...a high and low pitch.

I want to make the horns work and also make them be like they would have been out of the factory as a part of putting in the wire harness that goes from the firewall to the headlights, etc.

The trick is I don't know exactly where the high and low pitch horns should be mounted?

I have checked both the Chilton manual and the Hayes manual only to find no guidance. I have been keeping an eye out for a classic Mustang on the road so I can ask but the local car club has everything except an old Mustang.

Does anyone know where exactly I should mount the high and low pitch horns?

 

I'm not sure if my car is correct, but my two horns are identical. As for the location, they're mounted behind the grill just above the radiator.



For newer vehicles the Haynes manuals are excellent, but the one for the older Mustangs is pretty useless. See if you can get yourself the Factory Repair Manual and the Osborne electrical assembly diagrams. They're pretty much essential for debugging electrical glitches. You can order them from Mustangs Unlimited, NPD or any of the other big mail order Mustang parts places.

 

Thanks a ton!

That picture gives me a clue. Mine has the one horn on the passenger side and it is mounted the same place as yours is. I had noticed the hole on the other side and figured that might be were the second goes but I wasn't 100% positive.

My main problem with the wiring on my car is that the wires are just old and the insulation is starting to crack. Second problem is the previous owner thought electrical tape on wires twisted together was the way to go. Guess it never dawned on them to purchase the proper harnesses where things plug in fairly nicely.

I was looking at the car over lunch and the main wire harness under the dash is going to be a serious pain. It appears from what I can tell that the previous owner snipped all the plugs off of the wires coming out of the bottom left on the steering column and replaced it with whatelse....electrical tape. So even if I buy a new wire harness with the plugs on the ends, will have to find the plugs to go on the wires coming out of the steering column among other places no doubt.

 

well if it comes down to it, you can do what he did... its not necessarily the worst thing, all things considered, but instead of twisting and using tape, use the twisty plastic cones. they will provide a good connection, if done properly, then i usually tape the wires together below them to help hold them to each other. again, clips and plugs are preferred, but this is not necessarily a terrible method.

 

Definitely get that second horn on, I love the sound of the two tone horns we have, just sweetens the appeal.

 

I hear ya Waffles.

Myself, I don't so much care for the twist cones. I usually use the deals where you put one wire in one end then crimp it then stick the other wire in the other end then crimp.

When I get around to wiring the car a bit at a time, I just might have to use those to get everything hooked up. Not the end of the world but sure would look much more clean with the proper plugs, etc.

Part of my problem now however with the park lights on the front coming on when the brakes are applied, etc is probably due to bad connections or things taped together allowing things to cross wire and so forth.

I have on order the dimmer switch. I am hoping that will make both my high and low beam headlights work, since that is the switch that would appear at least to be the problem. From there I am going to buy the wire harness that runs from the firewall to the head / park lights and get the horns installed. The wires on the park lights are really old and worn so plan to start replacing / rewiring things a piece at a time.

After I get the front done then I will probably do the back harness then see where I am at with things.

Most of the wires under the dash look ok other than someone wiring them in a half baked way. The wires on the inside probably are not as worn and all the items on the dash work so may be able to delay spending the money on the under the dash harness for now at least.

 

btw in my 64 the horns were MASSIVE. they didn't workanymore and i threw them out and replaced them.
NPD have concours correct ones and plastic ones. I ordered the plastic ones and they're loud!
The two-tone is really great. Love em. Was one year without horns and now I beep wherever I go ...

 

I hope to be "beeping" soon as well.

This weekend I am going to get my dimmer switch replaced since UPS says it will be here Friday and then put on my new dash pad that has been sitting in the garage for a good week now waiting on me to get time to put it in. The current pad doesn't look "that bad" but it does have a large crack on the passenger side. Since everything else in the interior looks really good minus some carpet fading figured I might as well replace the dash pad since the part was under $200.

From there, I am going to go ahead and order the headlight wire harness, the high / low pitch horns and kicking around the idea of going ahead and replacing the park light body, retainers, gaskets, etc since that all looked pretty old / worn when I crawled under the front bumber the other day.

 

There are two things that are always overlooked when building/rebuilding these old cars. Most people try to retain the original wiring and for some unknown reason believe that 40 year old factory brake lines are just fine.

IMO, both of these areas should be replaced before attempting to drive the car on a regular basis with any kind of reliability.

You're correct when you state that the portions of the wirning harnesses exposed to the elementsare in worse shape than the underdash harness, but trust me, the underdash harness ain't what it used to be. You'd be doing yourself a big favor to replace every harness on the car. The one harness that isn't replaced will keep coming back to haunt you. You mentioned that the connection for the steering column had been removed/hacked.... this can be rectified by installing a new turn signal/steering column harness.

Think of it this way....

It's common knowledge among mechanics that the positive battery cable, although appearing fine on the outside, corrodes on the inside. This can lead to starting/charging problems. Everyone accepts this and has no problem replacing the positive battery cable when troubleshooting starting/charging problems.... of course the new cable can be bought for usually under $10.

The rest of the cars wiring is slowly deteriorating and suffering the same fate as the positive battery cable, but with a $1000 price tag to replace, most people seem to think that the old wiring will be okay. It won't be. It's a harder pill to swallow due to the higher cost involved, but there's only one right way to do it.

Don't even get me started on brake lines.... that corrode from the inside out...

Dave

 

Funny you should mention brake lines, when I first got the car job one was to rebuild the front end (ball joints, idler arms, etc) and did a serious brake job on the car at the same time. The rear brake line in particular was in really bad shape so we did put some new lines on.

My general plan is to eventually rewire the whole car. The battery cables, plug wires, etc are all new. Now I am going for the headlight harness because I can fix several other problems at the same time, such as the horn and somewhat worn looking park lights. From there I am debating which one to do next...debating between the rear end harness or the under the dash harness.

I am spreading the job out some to spread the cost out mostly but also seems easier in the frustration department to do it a little hear and a little there....Slowly but surely.