I got an 80 F-250. I swapped in an entire under dash harness from an 86 model. Swapped the instrument cluster also. The only thing original I left in the truck was the steering column harness. Plugged everything up and everything works fine except only my drivers signal light works and while it's on it has all the dash light blinking with it. The flashers don't work, the passenger signal doesn't work, no horn either. I went and got a column harness from an 83 and plugged it in and still have the same problem.

Any ideas?

Thanks,
Sean

 

The wiring and turn signal switch from a 1986 is different than a 1980 and a 1983.

You will need a steering column harness and turn signal switch from a 1985-1986.

You did not say what steering column you have? Standard or Tilt.

Also you will need to change the Headlamp switch if you didn't do this already with one from a 1981-1986.

The headlamp switch for a 1980 is internally different to a 1981-1986.


These two things need to be eliminated as problems before we can go further.

I'd replace the headlamp switch with the proper one first, (If not already done so) as on the 1980 the horns get their power from the headlamp switch, and you may be backfeeding the fuse panel from the headlamp switch using the wrong one.

 

Well that explains it. It's a standard column. I think it still has the 80 headlight switch.

 

Here are the part number differences...

Standard Column Turn Signal Switches:
1980-1983: E1HZ-13341-K
1984: E4TZ-13341-A
1985-1986: E5TZ-13341-E

Headlamp Switch:
1980: E0TZ-11654-A
1981-1986: E1TZ-11654-A

 

Thanks for your help, you've been great.

 

Would anyone have a line on a harness or know where I can get one. I've posted in the classifieds and the junkyards around here will not just sell the harness, instead they want to sell me a whole column which I don't need.

Sean

 

I recommend you get a new turn signal switch, which comes with the column harness you need, or get a turn signal switch out of the wrecking yard.

Most Wreckers that pull the parts themselves will not split up a turn signal switch and column or steering wheel, or horn pad for that matter.

However if you have a u-pull-it, they do alow that there.

I also do not recommend splicing on the turn signal harness, as this can cause weird problems.

 

I'd pull it in one piece anyways, no way would I cut and splice. The only yard around here that has a good supply of these trucks, wants 125$ for a column. Kind of steep for a run of the mill, non tilt 80's truck column if you ask me. This is about the only part holding me up from finishing the interior of the truck, go figure

 

Okay, so I replaced the headlight switch with a new one for an 86 model and also bought a new signal light cam and harness for an 86. Still have the same problem. Also when I pull the headlight switch my left signal light comes on. This has really got me beat.

 

Update, if you can call it that...

For starters I rechecked my fuses to be on the safe side. The only problem I ran into was the horn/cigar lighter fuse was blown. Kept blowing them until I unplugged the cigar lighter and it put a stop to that.

Next I pulled the headlamp switch and signal switch out of my daily driver 1985 F-150. Plugged it all up and still have the same exact problem. Still only have left turn signal, unless I pull my headlamp switch and then it stays on all together. No right, no flashers still. Horns aren't hooked up right now, but they probably don't work either. Only my seat belt buzzer works.

The only thing I can find that may be a problem is the 1986 harness that I put in my truck had a tach. I'm using a cluster with no tach, but full manual gauges like the 86 had. Also the 86 had cruise, would that make a difference? I don't have the bed harness hooked up because isn't a bed on it right now, but surely that wouldn't affect it.

 

The Cluster with tach is swappable for a cluster with oil/ammeter gauges. for the following years.

1980 Only:
1981-1986


Just a thought, you are not using the 1980 instrument cluster are you? The one with the green printed circut on the back. The 1980 cluster is also different to 1981-1986 with the red printed circut. (The red can fade to brown). The 1980 is a one year wonder for alot of it's electrical parts as you are unfortunately finding out. If you are using the cluster from the 1980, you will need to either rewire the cluster connector a little bit, or get a 1981-1986 cluster with gauges or tach. Then of course the 1980 instrument cluster bezel is different as well to the 1981-1986. The lights on top are in the wrong order to work properly between the 1980 and the 1981-1986. The lights affected are the turn indicators and the brake and fasten belt lamp locations are transveresed.

Also not having the rear harness hooked up, will affect your lights. You need the whole rear harness hooked up with the bulbs installed. The 1984-1986 had the ground wire for the lamps in the rear harness, and it hooks to the frame. The 1980-1983 the lamps ground to the bed. Also check and clean the grounds to the fenders in the front to make sure they are connected.

Don't worry, replacing the headlamp switch and turn signal switch was nessecery to make things work properly. Most notably for the horn and to keep the fuse panel from being back fed power where it shouldnt go.

 

I'm using a 81-86 red circuit board. It has the E1 part number. Also have the 81 and later bezel. So you think my problem could be coming from not having the bed harness hooked up? I still don't understand why my left signal light would stay on when I pull my headlamp switch.

I just hope it isn't in the harness anywhere. I looked it over real good when I pulled it out of the other truck. The reason I pulled it out of the 86, was because it looked in such good shape. Only reason it was in the junkyard was due to the transfer case going south.

Just to make sure though, where would I be able to get a diagram to make sure my instrument cluster plug is pinned right. It looks like it has been messed with and I can't look at my daily driver 85, because it has the lights instead of full gauges. The wiring diagram in my Haynes manual leaves a lot to be desired lol...

 

Yeah the rear harness is where the lights get it's grounds from.

The taillamps and the brake/turn signal lamps share the same ground wire. Without the harness hooked up, power will try to find it's way to ground any way it can. Through the headlamp switch for instance. When you turn power on to the headlamps, it cancels the ground.

Hook up the rear harness, and we can go from there.

 

Alrighty, well apparently I've got to go back to the junkyard and pull a rear harness for an 86, since my 80 wont plug into it. Thanks for all the help so far, cause this sure is driving me crazy .

Sean

 

Factory wiring diagrams can be had for pretty cheap...

Service Manuals, Owner Manuals, Wiring Diagrams, Service Bulletins - Helm Incorporated - the original publisher, sometimes still has brand new ones.
eBay

I bought some stuff from this place and am happy:
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