1981 straight six manual 4x4 project

For what it's worth, from what I can tell the connectors for my DSII harness seem like they'll match my harness which was originally mated with an EFI 302. But without the ignition module, I can't verify for sure, and am in the same worried boat that there will be multiple differences keeping me from running my DSII harness with my main wiring harness originally used with EFI.

I bought an 82 F150 351W in Kansas which came with a feedback system and an ECU under the driver’s seat. I pulled the ECU and associated wiring, and plugged a DS-II harness in under the hood. Worked great.

Gary Lewis wrote

I bought an 82 F150 351W in Kansas which came with a feedback system and an ECU under the driver’s seat. I pulled the ECU and associated wiring, and plugged a DS-II harness in under the hood. Worked great.

Very good news for me! 😁 Hopefully Shaun will be in luck with the EFI wiring as well, since the connectors are the same... thanks for the good info!

I'm gonna go out tomorrow and match the connectors up so that I can cross it off my list.

Well... I never got to the main harness last night... I was trying to charge my AC first, and change out the passenger door while I waited on the vacuum draw down. Things did not go well. No AC = no trip in the truck this time ☹️.

The dryer unit that I bought vanished into thin air. I reluctantly decided I would use the old one. I went to put on the new hose for the straight six engine application and it was way wrong. It had a totally inappropriate 90* bend at the compressor end. (Silver lining... it looks like it’s the correct one for an IDI). It is very tight, and I had to tweak the dryer tube, but I managed to stretch the hose from the 302 compressor donor across the 300 and hook it up. When I find (or replace) the missing dryer, I want a different hose. There must be something better than this in current production:





Next came the task of figuring out how to change the compressor clutch wiring from the York single pin to the two prong plug. I hooked up the vacuum machine, and other than the resting needle position being above zero, it seemed to be working (Autozone loan program tool). When I went to fill it, refrigerant started spraying out where the yellow hose connected to the manifold. Problem 1, an obvious leak. Problem 2, refrigerant could not enter the system. Turns out the R134A adapter wasn’t opening. This meant the hours of vacuuming and leak testing were meaningless... 😩 I borrowed another adapter from the bricknose parts truck but it still wouldn’t take much refrigerant. Pressure valve wasn’t working. Borrowed that too... finally got voltage at the clutch and it sounded horrible at first. It started to settle down so I decided to run it. It took 4 cans (12oz) minus what leaked out of the manifold (I finished the job with a cheap-o Walmart refrigerant dispenser. The air started to feel cool, then the compressor started to grind and stalled the engine. I’m guessing it was just bad (JY take-off) and/or dirt from the old dryer finished it off. Either way I’m sunk. I have two other compressors but I’m not inclined to try them without a new dryer, correct hose, and a working pump/manifold set. I don’t have time with everything else I need to do and leave Friday.  We knew it was reaching, and just about everything went wrong that could.

But... while I was wasting hours of time with the vacuum sucking on a broken valve... I did change the badly damaged passenger door. The replacement came from the Kingman junkyard and was just a bare shell. I had to move all of the glass, weatherstrip, door handles and latch, key tumbler, mirror etc., out of my old door. This took a minute especially since I had never taken the glass out of one of these before. Then I found out just how not fun it is to align one of these.... it takes 3 minutes to remove one, and almost two hours to get one back on in kinda the right spot. And hopefully you don’t care about the paint 😅. Funny, there were already a bunch of crescent shaped scratches from where a PO had aligned this door on the donor truck. I recognized immediately where they had come from once I started trying to work the bolts via the gap between the fender and the open door. It’s not pretty, but it does look better than the smashed one. It also closes a heck of a lot better and hopefully won’t chew up the striker sleeve any more. And the biggest motivator, the glass can now be rolled up and down without pliers! Yay.

And as Jim [and Gary] has been known to say, "progress is good!"

That sucks about the A/C Jonathan, but the new door looks good!

Not to hi-jack, but I checked my DSII harness against my 1986 chassis harness and everything matches up like it should, so I am good to go.

Bummer about the A/C, Jonathan.  But at least you got the door on - and can roll up the window!  

Shaun - Good to see that the harnii pluged together.  

Jonathan, that dose stink about the AC.

Is the truck an 81 in your sig?
If so and using the newer compressor, the 81 should use a York, here is what I had to do to get a complete sealed system on my 81 using the newer compressor.

You have to use a 81 dryer as the newer one will the fit the evap, different thread size so you have to use a dryer for the 81 to fit the evap..

So now on to the hose, you cant use a newer hose that would of fit the newer dryer as it will not fit the old (81) dryer, different thread size.
What I found was the old 81 hose that fits the old (81) dryer also fit the new compressor.

But ........ the hose runs totally different than the newer hose would, compressor to and across firewall to dryer. I don't remember how the York hose ran as I never had that system on my truck, remember all my AC parts came from my parts truck and the motor was sold before I bought the truck.
I don't have a picture of how the hose runs but it kind of goes across the top of the motor.
I also had to "tweak" the dryer & hose to clear the hood when closed but was not much.

As for the vacuum pump & gauges I bought new from HF.
The more thinking I did on the pump I did not know what I would be getting if I did the "loan-a-tool" if it come pull a vacuum. Same on the gauges if I could have even gotten a loaner.
My gauges only hooked up to the low side, guess I needed adaptor for the high side? But I was able to pull a good vacuum and it held for an hour while I did the electrical wiring side.

I did use a lot of cans of 134 before it would blow cold but the low side reading where in the green other wise it was to low. I would have to go back through my posts to see just how much if you need that.
Dave ----

Thanks Dave, apologies that I am only just now seeing this. I have been out of town and off line most of the time.

I got a set f 83+ AC brackets, and the compressor, dryer, and hose came from a 1985 Bronco with a 302. I bought a hose and dryer from RockAuto that was supposed to fit a 1986 300 six application. The hose was way wrong at the compressor end, and I managed to misplace the new dryer. I did the rental because this was a last minute thing, and there seem to be better compressor/gauge manifold sets for less money on Amazon than what HF had on the shelf. I will buy a set for the next time I try this. I’m not quite sure what I want to do about the hose, the 302 one does actually work but the fitment is awful. The one from RockAuto is absolutely a no-go, but will fit my IDI. I might order a hose from a local parts house so it’s easier to return or exchange if it’s wrong.

No problem we all know life gets in the way of our trucks LOL

You do have a whole lot of different year parts for the AC

I just wanted to let you know what worked for me on my 81, using I think it was a 85 compressor I picked up from the junk yard.

Good luck on the next go at the AC.
Dave ----

So judging by Max’s post (http://forum.garysgaragemahal.com/York-to-Sanden-AC-compressor-questions-tp60023p60095.html) I seem to have the wrong compressor for the AC hose that I purchased... the connections point straight back instead of out the side. Since this compressor appears to be ruined anyhow, it looks like I may need to get the right compressor for 83-86 straight six.

I dont think is the compressor bolt on hose fittings don't come with the new compressors.
At least what I saw in pictures so you may want to check into that.

Because of that I checked Ebay and found them for $100 each.
That was one reason why I went with a junk yard compressor for $75 cash.
Good luck
Dave ----

edit: If you look at the compressors in the pictures you will see they are different.
IIRC the ones for our trucks use the ones that bolt on the side.
The other compressor has the hose connections on the rear.

I dont think is the compressor bolt on hose fittings come with the new compressors.
At least what I saw in pictures so you may want to check into that.

Because of that I checked Ebay and found them for $100 each.
That was one reason why I went with a junk yard compressor for $75 cash.
Good luck
Dave ----

edit: your pictures have 2 different compressors in them.
Our trucks use the side bolt on hose fittings.
The other has them off the back and I don't think they bolt on.

Dave, I didn’t even think about the connectors being a separate part from the compressor but you’re right. I have a junkyard compressor that I found in the cab of a truck that was new in the box— never installed. It has no connectors. I should probably source some for the straight six, and buy the second hose if needed (and I probably will).

When I was looking up different compressors is when I saw some had the hose fittings off the back like the one you pictured. They were mostly for after market AC systems IIRC.
Also someone pointed out to me a compressor think for a Jeep that had the hose fitting off the back side.

The compressor for our truck from the factory had the bolt on hose fittings that were on the side of the compressor. I just had to make sure that the JY compressor had the hose fittings other wise it was for nothing as I did not have them.
Dave ----

Well 💩💩💩……



This is the second time I have had this failure in my life of owning straight sixes… both times I was being extremely gentle and snugging the two bolts alternately, a little at a time.

Fortunately this time I had an older type, cast iron housing to replace it with. And fortunately I was able to find it when I needed it which I am hard pressed to do these days 😖.

The down side is that the cast iron one has no provision for a temperature sensor (which I was using for my electric cluster gauge), and the heater hose nipple is short, so my existing heater hose no longer fit. Not a big deal except it’s our water truck and when your cistern is running low and it’s late evening on a Friday these are the kinds of road blocks you don’t want. Never again with the pot metal thermostat housing… for now I will just add the electric gauge to the list of things that don’t work.

When I bought the new thermostat, the clerk suggested a fail safe. I was under the impression that most new units were designed to fail “open” but I guess not? We compared thermostats and the $6 to $12 ones did not have the mechanical provision but the $21 Fail Safe one did. It seemed like an excessive price difference for a couple brass tabs, but I guess the $15 will seem well spent if it fails on me in Bullhead City when it’s 122*F outside.

The truck overheated and I saw bubbles coming from the thermostat housing gasket joint… but the root cause of the failure was the water pump. Odd thing is it didn’t give me any of the warning signs that I’m familiar with, except a bit of belt chirp that I often hear anyway. When I pulled the belts the fan pulley was rocking up and down almost 1/4” 😱.

The old ‘81 still needs love, I went to start it after the water pump change and had zero power anywhere in the truck. Completely dead. Battery had over 12.3v but nothing in the cab. I cleaned the contacts and grounds, nada…. I fumbled about tracing wires and found nothing. Then as mysteriously as it died, it started working again… which allowed me to get a tank of water but that’s the very worst kind of “fix” 😬😬😬.

BumER!  Did the thermostat slip out of the depression?  Or is that one of the ones that the thermostat can't slip out and the pot metal just failed?

And 1/4" is a lot of slop on a water pump pulley.    I'm surprised you weren't spewing coolant past the seal.

Yes, you need to give it some TLC.  I'll bet it is lonely and its feelings are hurt.    But glad you got it back on the road, sorta.  I HATE fixes where you didn't really fix it as you know it'll come back to bite you at the worst possible time.

My housing did the same thing but I found mine when I was cleaning the old gasket off.
I could not get the last bit of gasket / sealer off and when looking closer saw it was cracked.

The Auto Zone one I get had the wrong size opening for the heater hose nipple.
I got the right size from O'Reilly's
https://www.oreillyauto.com/shop/b/engine-cooling/thermostat-housing-water-outlet/248157cbd990/v/a/5281/automotive-truck-1981-ford-f-100?compares=MRY-84913,MCS-4913KT,DOR-902-1025

Dave ----