Larry the Lariat - My 86 F150 4x4

I repositioned the ignition switch. It just didn't seem right before. Does this look right or was the previous one?

I'm honestly not sure anything was won't with my old ignition switch. Replacing it did not fix the things that aren't working. Still no wiper, no radio, no blower motor. I've been through the fuse panel up under the dash on the driver's side (is there a second one I'm not aware of maybe?) and all the fuses are good.

I guess I'm going to start examining closely what wiring was messed with when trailer brakes were added years ago. You can tell from those wonderful blue splices they used that it was professionally installed. 😖

OK, so the radio wiring looks... Factory 🤦🏻‍♂️😳🙄



Only thing I can figure is someone put a Ford stereo from some other vehicle in this, and just spliced in the donor wiring harness.

I'm guessing the two Gray couplers are factory, and the two black one is from the harness of whatever Ford donated it's stereo.

I'm gonna guess maybe in this cobbled up wiring is the "why" that the radio doesn't work, or maybe it's just bad. I pulled it to see what wiring liked like behind it, not expecting to see this mess.

Does the windshield washer pump work when you push the knob?
Do the 4-way flashers work?
Have you investigated the *thermal* fuse on the blower resistor board screwed into the air plenum?

ArdWrknTrk wrote

Does the windshield washer pump work when you push the knob?
Do the 4-way flashers work?
Have you investigated the *thermal* fuse on the blower resistor board screwed into the air plenum?

Washer pump works with the key in the ON position, but not in Accessory position. I'm guessing that's expected but not sure. No wipers in either position.

Hazard lights work fine on all four corners regardless of key position.

I haven't checked out any of the blower stuff yet. Does removing the glove box get you access?

Okay, so you have power through the wiper switch.
If you have no wipers, next you need to check the wiper motor ground at the cowl.

If the hazards work swap the hazard flasher from the back of the fuse panel for the blinker flasher that's on the front.

The blower motor and resistor 'speed' block are under the hood screwed into the plastic plenum.
The blower motor has power at all times in 'Run' and the climate control switch just shunts the ground through various wirewound resistors on the board.
This is inboard of the blower motor itself and should be a yellow or red fiberglass circuit board with a screw at each end and a central plug with 3 or 4 wires depending if you have AC or not.

This is also the thing that will set leaves on fire if your cowl has pine needles or mouse nests!

High speed bypasses all the resistors but not the thermal fuse (metal can)
You can find the test procedure in the appropriate EVTM section.

If it checks out it may be that the blower is pooched.
That comes out with 4-5 screws. See that the squirrel cage spins freely.
If it does you can jump 12V directly across it to see if it spins up.

by all means take the resistor assembly out and inspect it first. the catch fire thing is real! on every truck brought back to life i pull the blower out and use a shop vac to clean all I can reach. I have not always done so and have stories to tell as a result
ive even roasted a mouse or two. let me add that toasted mouse piss is NOT the smell that you want in your truck. chicks don't dig it.

mat in tn wrote

by all means take the resistor assembly out and inspect it first. the catch fire thing is real! on every truck brought back to life i pull the blower out and use a shop vac to clean all I can reach. I have not always done so and have stories to tell as a result
ive even roasted a mouse or two. let me add that toasted mouse piss is NOT the smell that you want in your truck. chicks don't dig it.

Aww come on! You’re just being dramatic! 😂



😳😳😳

LOL!  Yes, that stuff has caused many a fire, or at least lots of smoke.  Glad you checked.

Gary Lewis wrote

LOL!  Yes, that stuff has caused many a fire, or at least lots of smoke.  Glad you checked.

Me too.  Turns out, I’m a lucky idiot. Lucky in this case that I’m an idiot.

There was nothing wrong with the blower stuff…it helps when you turn things ON. 🙄

I’m used to my 70 F100. Turn the blower to high and it comes on, no matter what everything else is set for. The 86 has this position called OFF. Funny thing, it means everything is OFF. LOL



I had the blower on high but the system was OFF.

I’m an idiot.

I’m a lucky idiot though since that prompted me to solicit help and get the advice to check for fire hazards. I just pulled the blower motor and cleaned out lots of leaves.

Thanks guys!

Now to put this back together and figure out what I’m doing wrong with wipers…or maybe there really is an issue with them. 😜

All of us have done things like that.  

But glad you got the stuff out of the resistors.  

I believe I have a bad wiper motor. I checked the wires at the motor per this post on another site, and had power exactly s described, but the motor doesn’t turn. Beating on it a bit, it makes noise but it is obviously not free.



So I guess I’ll be sourcing a motor. Hopefully that swap isn’t too bad. Looks WAY easier than my 70 where it’s up inside the dash.

I believe I have a bad wiper motor. I checked the wires at the motor per this post on another site, and had power exactly s described, but the motor doesn’t turn. Beating on it a bit, it makes noise but it is obviously not free.



So I guess I’ll be sourcing a motor. Hopefully that swap isn’t too bad. Looks WAY easier than my 70 where it’s up inside the dash.

It does seem like you have a motor problem.  But you could try the tests from Ford's factory shop manual on our page at Documenation/Electrical/Windshield Wipers.

It could be the magnets have come unglued from inside the motor case.
*** Or often the output bushing wears out and the transmission binds up.

Changing isn't too difficult but you probably want to get new plastic bushings for the wiper linkage (Dorman/HELP has an assortment)

Removing the cowl is a little tricky but you can prop the hood about 1/2 way and sneak it out.
I common 'upgrade' is the '87-90 'polka dot' cowl. These help a lot in keeping those leaves out of the blower and plenum.

dramatic huh??  light that puppy!

mat in tn wrote

dramatic huh??  light that puppy!

LOL, it probably was about ready to light. Some of the leaves stuck to the resister already had burn marks on them.

The more I work on old vehicles the more I realize it’s a balance of “Make it go”, “Make it stop”, and “Make it not burn itself down”.

I revived an f250 this winter. an 81 ranger camper special. on one of the test drives I decided to stop at o reillys and get fuses as I had found the one for the blower bad. while at oreillys I replaced the blown fuse. now I know better, but I still quickly turned the blower on and back off just to check if it would make any noise or movement. halfway back to the shop I realized just how quickly that tinder can ignite. everything is turned off. but I'm smokin. I get caught at the only light in town. then I come rolling into the lot and shut it down and bail out running for a 5/16 nut driver. the resister fell out as it melted the housing around it.
I will tell these stories to make anyone laugh but mostly to say "DONT DO THIS". my childlike curiousity bites me sometimes.

Anyone know right off what this ground “blade” might go to? I’m guessing it’s what’s left of a broken connector that’s not used in my application but I’m not sure. I didn’t realize it was loose until I pulled the ground off the bottom (passenger side) screw of the wiper motor.

Working Wipers! Yay! And they are intermittent now as I swapped in a different switch while the dash was apart.

I used a Cardone 40-290 wiper motor I got from O’Reilly. No where near an exact replacement, but I’m in business again.





I had to swap the arm over of my old motor as the new one was WAY off from what is needed. I also had to enlarge the hole on the old arm to make it fit on the new motor.



As you can see, the arm that came with the new one was keyed 180• off from what is needed, and the stud the wiper arms connect to was way too short.

Only other issue was minor, as the ground wire for the motor came with a fitting instead of an eye. I just swapped on adifferent wire (didn’t want to mod the original in case I had to return the motor).

My grommets all seemed good so I returned the Dorman Help package I had picked up when I returned my core (whopping $6 core charge).



I figured out that removing the lower bolt, and loosening the upper bolt where the hinges bolt to the hood helps get the hood out of the way to remove the cowl without having to remove the hood completely, which is great when working alone.





I then put the instrument cluster and the steering wheel back on. I’ll leave the trim off until I’ve done done driving and am sure I’m done.


Started making new nylon fuel lines using the stuff Gary recommended (thank you sir!). I sandwiched two pieces of scrap wood in a vise, drilled a 3/8 hole through the joint, then loosened it, fed in the nylon, then 10 seconds with a heat gun, and tapped the fitting in using a hammer against 3/8 socket I dropped in where the removable bit of plastic goes. Super easy.