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Front Lights mystery

  • Thread starter Thread starter 68converted
  • Start date Start date Oct 25, 2008

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Oct 25, 2008
#1
  • Oct 25, 2008
  • #1
I know you guys love a good mystery...

Ok, my front lights do not work at all: Headlights, front blinkers, side markers/blinkers.

Here is what does work out back: Brake lights, Emergency flashers (back only), turn signals just come on steady. Reverse lights.

From the lights switch: it will dim the dash lights, and the rear driving lights come on. All the interior lights work, the heater motor works, power top is ok too.

So there is the mystery. The only thing I could find just as I was leaving the shop was what looks like like a ground that is just off the drivers side light harness.

What do you think?
 
M

mustangman1974

Member
Jan 17, 2004
463
0
16
Oct 25, 2008
#2
  • Oct 25, 2008
  • #2
mine has grounded on both sides by the headlights. Also check the harness plug by the firewall.
 
6

66Resto91

20+ Year Stangneter
Apr 26, 2004
17
1
3
Oct 26, 2008
#3
  • Oct 26, 2008
  • #3
Time for a new headlight switch. I had the same problem on my '66 coupe, and the new switch fixed it.
 

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Oct 26, 2008
#4
  • Oct 26, 2008
  • #4
66Resto91 said:
Time for a new headlight switch. I had the same problem on my '66 coupe, and the new switch fixed it.
Click to expand...

I don't think it's the switch. When pulled on, the rear lights come on, and when you turn the dimmer it dims the dash lights. I would think a bad switch would affect everything?? I found a spare blinker relay so I will also swap that out to see if they will actually blink.

I have my assistant back today (10 yr old son) so we will do some voltage tests and report back. I did go with HID headlamps from Sylvania?? Would that cause the entire front section to shut down? (I plan on doing the relay'd headlight conversion over the winter...)

I'll also hook up the hood blinkers and see if they are working. Forgot about those... the hood has been off for a few years LOL>
 
G

Grabber70Mach

Member
Jul 6, 2003
305
0
17
Indian Head, MD
Oct 26, 2008
#5
  • Oct 26, 2008
  • #5
I would think the headlight switch also found this picture I saved awhile back, it is of a headlight switch for a 69-70, don't know if it would be the same as yours. But I think they are all pretty much the same.

 

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xoxbxfx

Founding Member
May 9, 2001
3,959
0
0
Southlake, TX
Oct 26, 2008
#6
  • Oct 26, 2008
  • #6
is it just the light circuit? Is the front half of the fuse block nice and tight? All the fuses good? Im guessing it is the switch as well.

If you are running HID lights, you need to install a relay.
 

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Oct 26, 2008
#7
  • Oct 26, 2008
  • #7
I got tied up with another project. I'll be able to check this out on Tuesday night. I am also going to just bite the bullet and do the relays for the headlights at the same time.
 

BarnStang

Founding Member
Mar 2, 2001
1,260
3
39
Hagerstown, MD
Oct 26, 2008
#8
  • Oct 26, 2008
  • #8
THe power for the headlights runs through the dimmer switch on the toe board. If you do not have power there first, there is no need to go further till you do. You will not have parking lights in the front with the headlights on. Parking lights are on in the front with the first detent on the headlight switch.
 

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Oct 27, 2008
#9
  • Oct 27, 2008
  • #9
BarnStang said:
THe power for the headlights runs through the dimmer switch on the toe board. If you do not have power there first, there is no need to go further till you do. You will not have parking lights in the front with the headlights on. Parking lights are on in the front with the first detent on the headlight switch.
Click to expand...

Good golly, I never thought about checking there I will add that to the check list.

You guys are great!
 

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Oct 30, 2008
#10
  • Oct 30, 2008
  • #10
Sorry it took so long to post this, I have been traveling. I was only able to take a quick look (at 12 midnight, LOL) before I am out of pocket again for a week, but I did find a couple of things out. I checked the back of the headlight plug by jumpering the appropriate terminals, and got nothing. I then checked the switch itself and it is opening and closing the circuit fine, based on the diagram Grabber70Mach posted (thank you)

So, I'm pretty sure it is in the harness?? When I get back I will check the toe switch. Note: I did pull the old voltage regulator out, as part of the EFI swap... In the wiring diagrams, there is an input from this to the headlights harness if I remember correctly. I just did not have time to dig into the schematics.

One week, one week... patience young Skywalker... Thanks guys
 

BarnStang

Founding Member
Mar 2, 2001
1,260
3
39
Hagerstown, MD
Oct 30, 2008
#11
  • Oct 30, 2008
  • #11
Did you have 12v to the center pin of the dimmer sw plug? Did you mean it's switching 12v ok, or did you just check the sw for continuity?
 

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Oct 31, 2008
#12
  • Oct 31, 2008
  • #12
BarnStang said:
Did you have 12v to the center pin of the dimmer sw plug? Did you mean it's switching 12v ok, or did you just check the sw for continuity?
Click to expand...

Checked for continuity only on the switch... kind of tight in there. I will have some more time this weekend, but I'll add it to the check list
 

68converted

Member
Nov 19, 2003
772
0
16
Colorado
Nov 2, 2008
#13
  • Nov 2, 2008
  • #13
Got it! It was the ground wire that I found in the plug cluster in the drivers side front. The turn signal issue was a bad relay.
 
G

Grabber70Mach

Member
Jul 6, 2003
305
0
17
Indian Head, MD
Nov 2, 2008
#14
  • Nov 2, 2008
  • #14
Glad that you got it figured out.
 
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