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70 Road Runner Turn signals

WileERobby said:
Are your tail lamps grounded ?
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WileE makes a good point. I had to add extra ground wires to my tail lights too. My turn signals/flashers worked, but my tail lights were noticeably brighter once I ran an extra ground wire to each socket. That "could" be an issue as well if your ground is "borderline"
 
PurpleBeeper said:
Hmmmm...... I wonder if the broken horn wire shorted out the turn signals? The horn ground wire is a short black wire that you can see if you remove the horn cover from the steering wheel. You can test the horn itself by running a long jumper wire from the + side of the battery directly to the horn connector (the horn is grounded to the body by it's bracket) & it should "beep" if its good. From there, I think I'd replace/repair the wiring and if that didn't work, replace the horn relay.

For the turns signals, maybe just look at the wiring diagram & trace the power? Somebody here might post a link to factory wiring diagrams & if they don't send me a private message and I will e-mail the diagrams to you. These guys are right about grounds too....I've had TONS of ground wire issues & I even ran a separate ground wire to each of my hood turn signals.

Oh yeah, and replace the flasher itself. That's the problem with mine right now. Neither turn signal works & it's my flasher for sure (you have one for turn signals + another one for the emergency flashers)
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Purple beeper, I looked again today at the wiring diagram. I see the two flashers you are referring to. I'm only able to find the flasher for the hazards. Are they identical in appearance? (Hazard flasher and turn signal flasher) according to the schematics they look like the same plug end. Hard to trace wires when they are in a bundle all wrapped up. Might have to tear some of the wrap off and get a good visual where they go. That won't happen until Friday unfortunately. I will put the new harness in and put the column back together before any more destruction. I was told there was only one "flasher" by Napa.

IMG_4766.JPG
 
Ethan said:
Yes, WilE they do appear to have a good ground. Inspected them. They seem to be clean and making solid contact

View attachment 568735
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Hey Ethan, are those tail light housing ground wires stock????

That would explain a lot for me if they are. I just recently figured out exactly what my tail light covers were (had them for years in a box) and I ran one screw in that hole to hold them in. For me, I had run an individual wire soldered to the side of each tail light bulb to get a better ground (did this 25 yrs. ago), so "maybe" I was just missing the factory ground wire to the tail light housing all along?
 
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Ethan said:
Purple beeper, I looked again today at the wiring diagram. I see the two flashers you are referring to. I'm only able to find the flasher for the hazards. Are they identical in appearance? (Hazard flasher and turn signal flasher) according to the schematics they look like the same plug end. Hard to trace wires when they are in a bundle all wrapped up. Might have to tear some of the wrap off and get a good visual where they go. That won't happen until Friday unfortunately. I will put the new harness in and put the column back together before any more destruction. I was told there was only one "flasher" by Napa.

View attachment 568688
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The factory hazard/turn signal flashers look very similar. I "think" both were round & one had a yellow stripe & the other had a green stripe....but don't quote me on that. The factory location is a PIA to get at (but close). I believe both are mounted right under the dash, by your knees in the driver seat, right where the very bottom of the dash "rolls under". There is a 2"-3" wide "trough" there & the flashers sit in that trough & are held in place by some "metal clampy things" so you can slide the flashers out by hand & push new ones back in. "Maybe" one is left of the steering wheel & the other one is right of the steering wheel?

Now don't quote me on any of this..... my flashers have been hanging loose under the dash since before I bought my car.
 
Speaking from experience... check the front signal housing to ground (both the socket and body). I had an issue with a socket looking 100% good but there was no continuity to ground. Where they are crimped into the housing they can rust underneath. Probe from socket to body ground and housing to body ground. Same for the rear
 
Like three wood says; I keep a wire with alligator ends just to make sure of a good ground whenever doing electrical. Think about this- u have a test light hooked to body(with bad grd.) & you can’t light the test light; is it no 12v OR bad ground? That’s what I use the jumper grd for.
 
WileE, yeah kinda but it's grabbing (hopefully) contact off the stud(?). Not a real bad idea though.
 
Ethan said:
I will check in the morning. I did order a turn single switch harness today.
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And will do absolutely nothing if your grounds aren't good. Run an alligator clip from the lamp housings to a good clean ground before you waste your time doing anything else.
 
Old style mechanical turn signal flashers worked by current flow. They needed x amount of current to heat a bi-metal contact. That's why they would not work with one lamp burnt out. It wasn't bad because you could always tell if you had a bad lamp. I tried looking up the two flashers/part numbers to see if there was a difference because the current flow would be different for two elements than for four elements. No luck but PurpleBeeper pointed out the possibility of two different flashers which makes sense. At this point I would suggest just getting a newer style electronic flasher. They work no matter what.
Good grounding can not be overemphasized. Check and double check but as you stated earlier
"Yes, They do. I have flashers on the dash lamps as well as outside all the way around."
Since the bulb element (left & right) is the same element for the brake and turn signal functions, your ground probably good as long as their brightness looks to be correct.
 
I will have a lot more checked off the list come saterday. I have the weekend booked to figure this out. I'll start by checking all grounds and installing new harness. Not that I can drive it but I want this fixed before spring! I work 12+ hr nights so I'm kinda beat when I get home. Just try and check (some) of the suggestions you guys have after a long work night. I appreciate the feedback and I will definitely let you know the soulution to the problem ;)
 
Not ur problem, but if u have a 1157 type bulb & one filament breaks and falls over to the good filament that’ll really make u pull your hair out.
 
PurpleBeeper said:
Yep, TWO separate flashers. Shorthorse has a good point.... try to tackle each job one at a time, but I'd still take a look under the horn cover to see what I could see based on the last owner saying the turn signals went out when the horn did.
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Replaced the hazard flasher at the beginning of this hassle and everything stayed the same (only the hazards worked) found the other little relay (turn single relay) and HELL YA everything works. I didn't get my book until last Friday and glanced at it here and there and realized there were 2 separate relays. Thanks I would still be tearing **** apart if it wasn't for you guys. APPRECIATE all the help fellas. The lights on the hood don't work but I got other things to fix before I worry about those. At least I can drive it legally when the time comes (more for my sake) hate to side swipe a car
 
Ethan said:
Replaced the hazard flasher at the beginning of this hassle and everything stayed the same (only the hazards worked) found the other little relay (turn single relay) and HELL YA everything works. I didn't get my book until last Friday and glanced at it here and there and realized there were 2 separate relays. Thanks I would still be tearing **** apart if it wasn't for you guys. APPRECIATE all the help fellas. The lights on the hood don't work but I got other things to fix before I worry about those. At least I can drive it legally when the time comes (more for my sake) hate to side swipe a car
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Boo Yah!.....and by the way...... are your two tail light grounds "stock"? I would like to change my stupid extra wires soldered onto each bulb socket if they are. Thanks
 
WileERobby said:
Hmm it looks like it's grounded to itself. You have to run a separate ground to the body.
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Exactly. Do not rely on the metallic housing of the taillight fittings to provide a good solid ground - the best ground is found under a bolt directly on the welded body work. A good jumper wire between the housing and the bodywork should be added also.
 
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