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Discussion Starter #1
I have a 68 fastback with tilt-a-way steering. I had the American autowire classic update kit installed by a pro. He came highly recommended and did a great job. He's a mechanic by trade but also specializes in classic rewiring.

We have an issue that we can't get around. With the headlights off, turn indicators work in the back correctly, but are crossed in the front. (left is right, right is left). When the headlights are turn on, all indicators are on constant. He's double checked all grounds, all lines and all bulbs.

His opinion is that the turn signal switch inside the steering column has gone. To my knowledge, I honestly cannot remember if the signals were working when I bought the car two years ago.

Has anyone run into this? Any suggestions?
 

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An easy way to know if the switch is working right. Is unplug it test conituity between the different wires in the different scinarios (left, right, hazards, brakes, etc...)

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OK, and myself being a novice on wiring, how would I go about testing it? I have a volt meter and a test light. I want to be sure it's that before I order one and pay the shipment and duties to get it to me.
 

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Did the person who installed your wiring harness use the new gm style plug that came with the American autowire harness or the stock style plug

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I had an issue with my turn signals (with the stock harness) and it turned out to be a bad brake light switch. I replaced the switch and the signals worked correctly again.
 

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This is a diagram of the wiring used on the american autowire turn signal conector. If you have an original style turn signal switch the colors will be different just pay attention to the letters on the connector. I'll post a video below that shows how to check continuity.


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Discussion Starter #8
753222

Here a pick. Looks like new plug. Thanks for the info and video. I will give it a shot.
 
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Discussion Starter #9
I also have an American autowire harness in my 68 mustang

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Thanks for the video. Where do I connect the negative terminal from the tester. Do I just touch a ground?
 

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Question: With the headlights OFF, do the turn signal INDICATORS work properly? If so, I suspect a wiring issue somewhere up front between the lamp housings as the front turn signals and indicator lamps are typically on the same circuit off the T/S switch.

With the funky operation with the headlights "ON" it sure sounds like a GROUND issue. Is the chassis ground between the engine and firewall properly installed? Try connecting one jumper cable between the negative battery post and the radiator support with the headlights "ON" and turn signal selected. Get a spark from the cable? Does it "fix" the problem? If not, next place I'd try grounding with a jumper would be the actual front parking lamp HOUSINGS themselves.
 

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Discussion Starter #11
Question: With the headlights OFF, do the turn signal INDICATORS work properly? If so, I suspect a wiring issue somewhere up front between the lamp housings as the front turn signals and indicator lamps are typically on the same circuit off the T/S switch.

With the funky operation with the headlights "ON" it sure sounds like a GROUND issue. Is the chassis ground between the engine and firewall properly installed? Try connecting one jumper cable between the negative battery post and the radiator support with the headlights "ON" and turn signal selected. Get a spark from the cable? Does it "fix" the problem? If not, next place I'd try grounding with a jumper would be the actual front parking lamp HOUSINGS themselves.
Correct, with the headlights off, the turn signals work correctly. The engine is ground from the heads to the shock tower. I've checked ground using a multi-meter from the positive terminal of the battery and touching the meter negative lead to a variety of places, rad housing, frame, heads, block, firewall - I get 13.4v.

The gentlemen that did the wiring is coming back tomorrow to recheck all the grounds again. He's determined to get to the bottom of it. I'm trying to help out where I can.
 

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Correct, with the headlights off, the turn signals work correctly. The engine is ground from the heads to the shock tower. I've checked ground using a multi-meter from the positive terminal of the battery and touching the meter negative lead to a variety of places, rad housing, frame, heads, block, firewall - I get 13.4v.

The gentlemen that did the wiring is coming back tomorrow to recheck all the grounds again. He's determined to get to the bottom of it. I'm trying to help out where I can.
So, the INDICATORS aren't "crossed up" but the actual lamps are?
 

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Discussion Starter #13
So, the INDICATORS aren't "crossed up" but the actual lamps are?
Not quite sure on what you're asking but currently when choosing left, the front right and the rear left flashes. When choosing right, the front left and rear right flashes. I've double checked the wiring harness, and it was all done correctly as per American Autowire manual. So I'm thinking he may have just crossed the wires at the front of the car. That's no biggy.

The more I think about it, the more I remember that before I stripped the car apart, the turn signals were working. My wife remembers laughing about how slow the turn signals flash compared to new cars.

I'm hoping it's just a ground issue or possibly a crossed wire somewhere.
 

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Thanks for the video. Where do I connect the negative terminal from the tester. Do I just touch a ground?
You are testing continuity not voltage. You will have red prong on the L terminal wire and the black on one of the other wires in the clip to test

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Not quite sure on what you're asking but currently when choosing left, the front right and the rear left flashes. When choosing right, the front left and rear right flashes. I've double checked the wiring harness, and it was all done correctly as per American Autowire manual. So I'm thinking he may have just crossed the wires at the front of the car. That's no biggy.

The more I think about it, the more I remember that before I stripped the car apart, the turn signals were working. My wife remembers laughing about how slow the turn signals flash compared to new cars.

I'm hoping it's just a ground issue or possibly a crossed wire somewhere.
I was asking about the INDICATORS in the instrument cluster. Do they match the FRONT or REAR when a signal is selected?
 

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Discussion Starter #16
You are testing continuity not voltage. You will have red prong on the L terminal wire and the black on one of the other wires in the clip to test

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ok got It. Thanks.

I was asking about the INDICATORS in the instrument cluster. Do they match the FRONT or REAR when a signal is selected?
oh sorry.... right the indicator is correct. The lamps are reversed.
 

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Discussion Starter #18
Yes, not too worried about the switched bulbs. That’s an easy fix. It’s the signals not working when the light switch (brand new) is on.

Another interesting bit of info... when the headlights are on, both dash turn signals are lit up, but when I select left, the rear and front indicators go slightly brighter. Same if I select right.

I think it’s a ground. The rear light harnesses should be touching the frame, correct? Also, I sandblasted, primed and put two coats of paint on them. Inside and out. Maybe they aren’t getting a proper ground?
 

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Yes, not too worried about the switched bulbs. That’s an easy fix. It’s the signals not working when the light switch (brand new) is on.

Another interesting bit of info... when the headlights are on, both dash turn signals are lit up, but when I select left, the rear and front indicators go slightly brighter. Same if I select right.

I think it’s a ground. The rear light harnesses should be touching the frame, correct? Also, I sandblasted, primed and put two coats of paint on them. Inside and out. Maybe they aren’t getting a proper ground?
Try a better ground a see what happens. I've had weirder things happen off of a bad ground

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Discussion Starter #20
SOLVED

Well, nobody saw this coming... It turns out it was improperly wired BRAND NEW turn signals I bought from CJ's. The wiring colors were correct, but the ground was swapped. After verifying the grounds were all good, he went to swap the reversed lamps and took another look at the wiring and bingo... found the issue.

All is well again.

Now, I just have to figure out the break light switch. I did a front disc conversion with CSRP and now the brake lights won't come on. It's a brand new Switch and it tests good. If I manually put more pressure on it, the lights will go on. It has something to do with the new push rod and the space between that and the switch. There's just the slightest bit of play between the rod and the light switch. Should it be tight?

The even sadder problem is now with the new harness in place, I will have to drop the steering column to access that damn switch. I winder if there's another way to do it like a pressure switch on the actual break line?
 
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