More wires than needed.

[bonedaddy]

So the PO did some "upgrades" but it looks terrible under the hood and makes everything confusing. There is a muscle car style MSD ignition installed, and the 3 vac motors (?) on top of the valve cover are disconnected, but the car runs good. I want to know what I can cut out of the mix and throw away from the firewall and get the harness sealed back up. Any ideas? http://http://photobucket.com/Bonedaddyeagle

[eaglefreek]

Man, what a mess. You probably have to trace each wire a determine if it's needed or not. Good luck.

[rohnk]

Wow, it looks bad but really isn't all that bad considering. Most of the harness is just that the sheathing is removed. It also looks lke a number of the fusible links may have been removed down in the ignition area.

While you are in there, this would be an excellent time to change that valve cover. It will give you some room as well to move the wiring around a little to spread things out and see where they go. Everything on the pass fender looks correct but there are a couple of extra taps off the battery from what I can tell.

Look up the schematics in the Eaglepedia to help yourself out on this job. Good luck and don't be afraid to ask questions!

[BenM]

As far as cleanliness, the whole ECM harness is mostly separate from the normal engine harness, and if you don't need to fix the emissions system, then start down at the firewall on the passenger side where it comes through, and pull it out. Looking at the way the connector for monitoring the ECM is chopped up, if you want to put everything back you may be best getting an new ECM harness anyway, that's chopped up badly. (Why leave it there?)

If you're not using the ECM, make sure that you have the correct wiring through the oil pressure switch to turn on your electric choke and manifold heater or it'll never work right when cold, I can't tell if that wiring is still intact or not.

Also, the "proper" distribution point from the factory is the battery terminal on the solenoid, it just looks cleaner then wires hanging off your battery posts. Every part of the car is a ground, so if someone feels the need to run a ground wire to the battery then I'd check all my ground straps, that usually indicates trouble.

Looking at the A/C routing I wonder if you have the dealer installed "American Air".

You're going to want to use the big TFI cap with the MSD or you're going to get crossfire problems. It's odd to spend all that money on the MSD and miss something as cheap as the TFI cap upgrade.

[bonedaddy]

Thanks guys, a lot of good info there. The carb has a manual choke old school push pull handle inside. I have no intention of emissions control in the future. I want this wired like a 50s rat rod. That being said, can I yank all those wires that go through the wall to the motocraft box (ECM?) ?? And those silver boxes on the firewall? I really would like to cut out whatever I don't need. I'm waiting on pushrods, rockers, and the valve cover gaskets and what not. There ordered.
I'm not familiar with the manifold heater, if you could explain that.
And what's American air? Thanks guys!!

[BenM]

The carb has a manual choke old school push pull handle inside. I have no intention of emissions control in the future. I want this wired like a 50s rat rod.

If you're going that route, you ought to put the Motorcraft conversion on it then and get the electric choke back plus a new carb will work better then an old tired one. (I like the BBD too...)

That being said, can I yank all those wires that go through the wall to the motocraft box (ECM?) ? And those silver boxes on the firewall?

The Motorcraft box is just the ignition, it should have been replaced with the MSD. If it's still there it's probably not wired up.

The AMC CEC system is connected to the ignition (usually between the sensor and the ignition module) so it can adjust timing, but it's completely AMC and it's inside the passenger kick panel. You ought to be able to pull that harness and most of what it's connected to, just be cautious as there are some connections with the other harness under the hood. If in doubt unplug the connector and leave it in until you consult a wiring diagram.

Some of those "boxes" are relays, you'll see what's connected to the CEC harness and what's part of other systems. You'll need a couple of those.

I really would like to cut out whatever I don't need. I'm waiting on pushrods, rockers, and the valve cover gaskets and what not. There ordered.
I'm not familiar with the manifold heater, if you could explain that.

It's pretty simple. There are three terminals on the oil pressure switch, one is the ground for the indicator light on the dash, the other two are connected when the engine is running. Power from the battery feeds into one and out the other. From there it powers the choke heater for your (missing) electric choke and a relay.

That relay has a heavy wire with its own fusible link to a junction point in the harness and it plugs into an electric heater that is installed in the intake directly under the carb. The heater draws a lot of current. Another wire from that relay goes to a temperature sensor in the intake that breaks its ground connection when the engine warms up and turns the heater off.

What it's doing is replacing the old method of having an exhaust heater under the carb so that it doesn't ice up and so that it doesn't have to run on the choke longer then necessary. 258s are quite cold-blooded and you can tell when all this is not working. When I put an aluminum intake on my Pacer I had to recreate the harness.

And what's American air? Thanks guys!!

It's a different way of installing A/C on a car that didn't come to the dealer with it. Your HVAC system is different than most Eagles with different parts, for example your compressor and alternator are in opposite places.

Do you have pictures of your dash on the inside? Pictures of the belt routing on the front of the engine? Those would really cinch weather you have American Air or a grafted on compressor and factory A/C.

[bonedaddy]

I couldn't log on for some reason for a few days. I'll get you those pics. Any links to related wiring diagrams for that harness?

[BenM]

I couldn't log on for some reason for a few days. I'll get you those pics. Any links to related wiring diagrams for that harness?

I think we all had problems.
Check the Eaglepedia Diagrams, The only thing I think it's missing is the full wiring layout. Check here for that.

A TSM would go a long way as well.

[bonedaddy]

I can't thank you enough for your time. I'm sorry that I'm so confused. Is the CEC the silver box behind the passenger kick plate? Or is there another item behind the box that says motocraft? The diagrams are helpful, but I'm not sure how to figure out what I need and don't need, and if I have to reconnect anything in order to bypass said items, lol. 
TSM IS GONNA BE NESSECARY.

[BenM]

Well, CEC is the whole engine management system, but the control box is the one behind the kick panel, and it should only say AMC. It's steel. (Except in 82 where I'm not sure, that's a different box but in the same place and I can't recall the material.)

The original electronic ignition box, which held the same function as the MSD box, is a Motorcraft part. It would originally have an AMC label on it, but I believe had "Motorcraft" stamped into the casting, and as they do tend to fail over 20 or 30 years some have been replaced with genuine Motorcraft modules. It would have been mounted on the passenger side inner fender and would be left natural aluminum. I can't tell from the pictures if it's still there or not.

The CEC manages the solenoid on the carb, and the solenoid wiring interconnects with the A/C and headlights through a set of diodes, it would step up one level when the A/C compressor, headlights, or rear defroster turned on, and on a higher setting using a vacuum connection on deceleration and some other cases when idle drops too low.

[bonedaddy]

If I do manage to trace out and remove the cec, which is disconnected right now but the car runs, is there any way to restore that function that controls the step down for lights,ac, etc? Or is that already not in use do to me having no electric choke?

[BenM]

Look though your wiring and engine for the diode pack.



Here's a diagram with it, it's toward the middle, look for the solenoid. The three arrows pointing at lines "-->|--" are near by, some of those diodes are diodes in that pack. The A/C, headlights, and several other things have wires that go into it, and then one wire comes out that goes to the electrical connector on the special "Sol-Vac" solenoid on the carb.

In addition to the normal step-up, some people here at the Nest have wired one of the vacuum solenoids to a switch on the dash and used it to trigger the vacuum part of the Sol-Vac to get the slightly higher idle it produces, which is nice on a winter night with all the accessories running.

Here's a good introduction to wiring I came across, if it will help when reading diagrams

[bonedaddy]

This is just awesome, thank you. The pic looks a lot like the pile on my passenger seat, lol. I have to find that diode pack. It must still be under the hood. I pulled the CEC and it's harness, and most of what I traced from it was cut on the other side by the PO. Those two "boxes" ( diag. ports with dust covers?) that you saw in the pics are gone, ( the ones on a bracket next to the wiper motor).  Everything still starts and runs. I still have a ton of wires that are cut I have to trace. My headlights don't work, but haven't since I picked it up. I'll find the diode pack and take some pics as well. Thanks!!

[jspeez13]

i was wondering how its going with the computer removal.  i am in a pretty sticky situation.  i have a non running car. im trying to do the mc upgrade and i have some mouse damage.  my thoughts were to romove computer and eliminate anything that doesnt need to be there. then i wouldn't be repairing mouse damage on things that are not needed.  can you pretty much pull the computer and trace and remove all connected components with the exception of the diode pack?

[ammachine390]

i was wondering how its going with the computer removal.  i am in a pretty sticky situation.  i have a non running car. im trying to do the mc upgrade and i have some mouse damage.  my thoughts were to romove computer and eliminate anything that doesnt need to be there. then i wouldn't be repairing mouse damage on things that are not needed.  can you pretty much pull the computer and trace and remove all connected components with the exception of the diode pack?

Since you have an 81 California model, you don't have to remove the computer or cut any wires. Just unplug the stepper motor from the back of the carb and you can be done. The 81 models that came with computers, did not have any ignition timing control, so there is no wiring that is necessary to modify, just unplug the stepper motor.