Hello all,

1977 f100 custom, 302, automatic C4 transmission

My left/right rear turn signals, brake lights and reverse lights weren't working. Sometimes my front turn signals weren't working. Last night I got into the dash to look for loose wiring and found this part...it was loose.



I pushed it back together and Eureka! My rear turn signals and brake lights now work. I'd like to replace this part (grey connector in the pic) because it won't stay well connected. What part name do I search for? What is this thing called?
By the way, my reverse lights still don't work and my brake lights are now always on. I think I can adjust or buy a new stop light switch for the brake pedal to fix the brake light problem. For the reverse lights I will check the bulbs in the morning.
Thanks in advance for the name of the grey connector part.
John

 

That's the turn signal switch connector. The actual metal terminals snap into the plastic housing and are in turn held in place by a red strip of plastic in the face of each connector.

That connector was used on several different models for several years, and should be easy to find in a junkyard. They also pop up on eBay from time to time (NOS). If you buy a new turn signal switch, the female end will come with the switch for you to snap each terminal into place. I have not seen the male end on the harness side reproduced. You should also be able to zip tie it together long-ways.

 

That would be the factory connector that to my knowledge isn't replaceable as a separate purchase. For now use a zip-tie or two to hold it together.

You should be able to find one at your local jy; cut the harness on both sides as you use your current wiring when you replace the connectors.


lol I type 2 slow....

.

 

No need to cut any wires. The actual terminals themselves snap out of the connector housing. On each end, there is a red strip of plastic in the center of the housing, on the face. This gets removed, and then each terminal can slide out by prying back the pull tab. Installation is the reverse - each wire snaps into the housing, and once they're in place, they get locked down with the small red strip.

When you buy a replacement turn signal switch, the wires are loose and the housing is a separate piece. Common practice is to snake the wires down the column while installing the switch, and once they're snaked through the column, the housing is installed as I describe.

 

I meant on retrieving the one from the jy; Sorry I wasn't clear....

 

Ah, got it now.

 

FMC and OldStyle,

Thank you gentlemen for the assistance. I bought some wire ties for the temp fix. If the problem happens again, I'll buy more wire ties!

Now it's time to put in the new stop light switch and replace the reverse light bulbs.

 

I'm having similar problems with mine. The directionals aren't working and reverse lights. I took the signal switch apart and cleaned the connections and changed the relay and still doesn't work. I just ordered a new switch and hoping that's the prob. BUT, my question here is, what is that other 'relay' in the second photo for? One I believe is the turn signal, what's the other one?

 

oh, I also forgot to ask...where is the switch/button for reverse? What makes the lights come on? I have a 77 F150 400 4 spd.

 

I have a 77f100 302 w/c4 auto trans. For my vehicle, the reverse/neutral safety switch is located in the steering column/wheel.
<O</O

However, you may want to check in the engine compartment where the steering column enters the cab for a backup switch (see below pic from 77 shop manual) but I think this switch if for manual transmission only?

You also can check if its on the driver's side of the transmission where the linkage meets the transmission.<O</O

 

A couple side notes:

1) The reverse lights are completely independent of the turn signal switch.

2) The two circular items in the bottom picture are flashers; one is for the turn signals and the other is for the hazards. It is incorrect to refer to them as relays.

 

On the 4 spd trannys. the switch screws into the cover of the transmission.
It should look something like this.

 

Ahh...thanks. I'll look for it..

 

That switch is for the four speed standards though I am fairly certain, what you need to look for is under the dash on top of the steering column, it is a neutral safety switch and a back-up light switch, it should be a switch mounted on a tab and there is a moving (with the gearshift) tab that hits the button in different places to allow you to start in neutral and park only AND to turn on the back up lights

 

There were 23 different wire connectors available by themselves for these trucks. But the parts catalog only lists the color and type # of same, doesn't have applications for which harnesses the connectors are for.

Look on the original for a ID number molded into the plastic, post what it is. The number will be similar to this: D3TA-14489-AA
-------------------------------------------------------------------------------------------------------------------------
If an A/T, the backup lamps are operated by the NSS. With a M/T, there is a separate backup lamp switch.

C7TZ-7A247-A .. NSS-Steering Column Mounted (Motorcraft SW-600) / 1967/77 F100/350 / Obsolete

D8TZ-7A247-A .. C6 NSS-Transmission Mounted (Motorcraft SW-1489) / 1978/79 F100/350 & Bronco / Obsolete

D8TZ-7A247-B .. C4 NSS-Transmission Mounted (Motorcraft SW-1491) / 1978/79 F100/150 / Obsolete
================================================== ============================
C9TZ-15520-F .. 3 M/T Backup Lamp Switch (Motorcraft SW-938) / Obsolete

Applications: 1973/79 F100/250 & 1973/77 Bronco.
-------------------------------------------------
D8TZ-15520-A .. RUG SR-OD 4 Speed Single Rail Overdrive Backup Lamp Switch (Motorcraft SW1487-A) / Obsolete

Applications: 1978/79 F100/150.
-------------------------------
6L5Z-15520-A (replaced C9TZ-15520-C) .. 4 M/T Backup Lamp Switch (Motorcraft SW-6396) / Available from Ford.

Applications: 1973/79 F100/350 & 1978/79 Bronco with T-18 & NP435 / 1979 F350 2WD w/T-19.

Excepting D8TZ-15520-A, these backup lamp switches were used on other years, but I'm not typing all the myriad applications.