Frame harness wires
 

I was crawling under my truck today since it to back from work a week ago and found two wires wrapped around my brake lines that I don't remember seeing there. I put the brake lines on so i know i didnt put them there. They are coming off the harness that runs down the frame to the brake lights and are spliced out prior to the fuel sending unit split. One looks to be pink but possibly purple faded and the other is black with a white strip. I searched my electrical diagrams for these and can't seam to figure out what they are. They spice out by the transfer case/ transmission off the frame harness. Thanks for the help in advance I don't want to have them taped off if they are important but I know they don't go to my lights as they are all functional.

Sorry failed to mention Wiring should be from a ford f150 as the frame was an add on and cab and electrical is from the 1980 f150.

Pulled the harness back and the wires are actually purple with orange strip and black with purple stripe. Sorry about the mix up fellas.

1980 was a one-year wonder (especially concerning wiring) so we'd need somebody with the 1980 books to verify, but this is what my 1981 wiring diagram says:

Black/pink-stripe (purple not listed):
Circuit 140 - backup lamp
Circuit 464 - module to lamp (no idea of which module or lamp, or location)



Purple/orange-stripe:
Circuit 131 - cigar lighter lamp feed
Circuit 612 - air bag ready indicator L (monitor) to center sensor

That's the main reason we need somebody with 1980-specific diagrams; you don't have airbags and I can't imagine there'd be cigar lighter wiring down there. ;)

The black/pink-stripe could very well be the backup lamps, though, probably coming from the switch in the transmission.

According to the '80 diagram I have:

Black/Pink goes from back-up/neutral switch to reverse lights - I don't see any black/purple wires in that area. Sometimes the stripes are extra heavy and look darker than they are meant to be.

Purple/Orange goes from fuse #15 to feed the back-up/neutral switch for the reverse lights.


Hope this helps

I'd take a lighter down there as long as I've been done there over the years! I think when they took out the transmission to do the rear main and transfer case they pulled them out of the neutral safety if it had one. And yeah just checked no back ups so theirs the black pink one which I believe ran off the neutral safety on a c6. Don't know for sure though.

Thinking this I tried to start in gear and it has a mechanical for reverse two and three that locks the key but I can start in first. Don't think this Is normal but I did have a Nissan one time that had a feature to let you bump start in gear. Don't know if a c6 is supposed to let a start in first or not. Im sure you all are more familiar than me to be able to tell. If these guys pulled that out they'll be fixing it.

Helps a bunch that would be it purple for power feed and black pink for lights. Such a pain dealing with 1980 electrical. Now I have to see if I need them to do a new neutral switch or if it can be hooked back up. Darned thing will run right over my front shaft. Also got to see if it's normal for the thing to start in first gear.

If you have a automatic, no it's not normal for it to start in gear. If I got this right, the harness is for a manual tranny setup? If so, see if it's like my 89(chances may not be good) and follow this harness up to under the power brake booster, where there may be a plug. If there is, unplug the harness and unwrap it a little bit, and you will find a red/blue wire made into a loop right behind the plug. The red/blue is the neutral safety circuit, and on the later trucks, the manual tranny trucks had this jumper at this spot, but the auto equipped truck's harness would have these two red/blue wires extended all the way down to the neutral safety switch, not letting it crank unless it's in neutral or park.

The earlier trucks had the same theme going, but I am not sure if they did it exactly like that or not. Usually people put a manual tranny in place of a auto, and during their first maiden voyage, they find it won't crank, and they have to twist these two red/blue wires together to complete the circuit to the starter solenoid so it will crank.

No it's an auto c6 and the only two wires under there are the ones for the backup Lights. Ive seen the four wire ones with the red wires but I don't have anything running down there or a harness anymore from the backup light switch on the tranny. I think these idiots tore it off and tried to hide the wires like I wouldn't notice. I tested power to purple and with key on I have power for backup then I spliced it to the backup light black wire still no lights. I have circuit at lights so I'm going to get new bulbs and see if it works that way. If it does then they tore my harness off and will be replacing and adjusting my backup light switch. Did they ever do the neutral switch on the front of the truck or mechanical and just do the backup lights off the c6?

The C6 has a single, 4-wire switch* that is both the NSS (red/blue-stripe wires, one end goes to the starter solenoid, the other to the column switch) as well as the backup lamps.

Do a Google search on "c6 neutral safety switch" to see pictures.

I will bet they spliced together the red/blue wires down there, that's why you can start in gear....

*EDIT*: This is only sometimes true, read more below.

If the harness or the truck was originally a manual transmission, there would have been a jumper plug on the starter circuits. On a 2wd truck the neutral safety wires run back to the transmission crossmember then along the frame a short distance to where they plug into the frame harness. Look along the left side just forward of your transfer case for a connector with 2 red/blue wires, 1 purple/orange and 1 black/pink. Ford really hasn't changed a lot of those colors since the 50s.

Probably was a manual harness because there is no red blue wires. Now I do have one on the starter solenoid that runs to somewhere I can't find in the harnesses. They must have spliced it somewhere to make it constant start.

I Spliced the 12v purple orange to the black pink and there are the constant backup lights. So I looked up behind the neutral safety switch and I can see where the wires got pulled out of the two holes for the backup lights. I was looking for a part number but all I can see is the ford motorcraft stamp. If I get home earlier tomorrow I'll take it off and see if there is a part number on it. From all I could see from the mirror was two holes where the wires come out. If I can figure it out I'll take a pic of it if it's only two wires. Regardless if worse comes to worse ill get the standard four wire one and only use the backup lights two. I can deal with the starting issue as it starts in park neutral and first not second or third so I don't have to worry about it starting in reverse.

Does anyone know why my key cylinder mechanically locks like it should preventing starting in third second but not first gear? Weird that it doesn't stop you from starting there. Thanks fella's!

If you can remove that switch from the transmission, do so, and include the numbers you see on it in a future post.

If a manual-transmission harness, some will have the switch the red/blue go to (if equipped) down by the clutch pedal under the dash.

I quite honestly am still confused as to what we're dealing with here... this is a C6 automatic transmission but the harness indicates manual transmission? In what year & model of truck?

Hey, post a pic of the Certification Label on the driver's side door jamb, we can tell you what it came with from the factory (assuming the cab and/or label haven't been changed).

The cab was a 1980 f150 AUTO 351W C6. The frame we tried to figure out before on here but we found out it was an 1984 f350. The ignition connector that comes from the cab that connects to the lower harness doesnt even have a red blue just the rear lights the fuel sender the brake proportoning and the backup lights. Weird to me to and to answer a prior post both the frame and cab were both autos with 4x4. Blows my mind but who knows with this truck thats why I call it a F-everything.

1980 pickups didn't come with 351W engines, would have been a 351M.

1980/81 didn't come with clutch-mounted switches to keep from starting without the clutch engaged, I *think* it was 1982 when they implemented that on stick-shifts. So, red/blue-stripe would go from ignition switch direct to solenoid (with manual transmission in 1980).