My 1987 Mercury Colony Park

[gadget73]

I used a standard Ford relay on my Towncar when I had that system in place, and it has the same ground wire that has to come out. I think the relay that is meant for the air compressor must be different than the usual Ford type because otherwise it would be a dead short. Best guess is that contact isn't actually a normally closed like a standard relay, but has a diode or cap or something to shunt any kick-back from the motor to ground without shorting out the power supply.

[Kodachrome Wolf]

Decided to get this whole thing done. Whipped out the NOS air shocks and tossed them in this morning. I put Gas-A-Justs in back in May of 2017 and those came out nice and easy. Such is the life of a non-rust belt car.

NOS Tokico OEM shocks:


Real Japanese content here:


I think both are from 1994 or a split between 1993 and 1994:



I found the rear air lines must have been clipped almost flush with the old shocks, so there was enough length left for me to just install the factory lines without any fuss or extensions. I did remove the linkage between the sensor and axle and greased the ball studs. Since the system really only works on "extreme" values from the sensor input (or at least that's how I read the EVTM), which is like 4.4v max each way before pumping or venting, it wasn't gonna run with the existing trim and I'm not heavy enough alone to sag the car out enough to make it go either. I decided to jumper the connector from the module to ground the relay and the compressor got to work.

Shockingly, heh, the shocks held air and lifted the rear about a good inch before I shut it down.


I got back on the bumper and jousted the car a few times. Firm and supportive is the best I can describe the reaction, similar to that of the KYBs that came off. I couldn't note any air leaking by from the fittings or shocks. Guess time will tell how long they'll last though.

[Kodachrome Wolf]

Probably the final update on all this air shock business for a while. Definitely need to adjust the trim settings for the shocks since I accidentally made a reverse adjustment so the system thinks the car is higher than it needs to be. NBD, just need to move the sensor a bit to the right spot and let it rip.

The regular gas shock dampening feels pretty good, so I can only imagine how it'll do with the base trim air added.

Here's two kinda lousy photos of the pocket mount:




The photo that's hard to get is where the air line comes out of (air cleaner is in the way). The compressor outlet is actually in the middle of the core support, but there was a perfectly sized hole that it conveniently lined up with and sticks up through. Probably a one in a thousand chance I'd just happen to land it there. With all the forward clearance, one could likely do a similar setup with the holder further forward if it could be adequately supported to offer better access to everything.

Definitely not a normal conversion for most folks as it takes a bit of work and fabricobbling to make it go. Likely easier to just retain the stock air cleaner and leave the compressor on the fender liner unless you're determined to run the later air cleaner and keep the compressor via relocation.

[gadget73]

The later compressors have the air line connection sticking sideways off the drier, the early ones I think are all sticking straight out the top. Probably why it lands a little funny.

[Kodachrome Wolf]

Okay, I lied about the final update.

Got a NOS control module for the system. Purchased a sedan one since it was the only style available, however the cover pops off easily and the board and be easily swapped between a sedan backplate and wagon backplate. Found the original control module was inop despite earlier inspection assuming it was functional.

Board for anyone interested:




Whole system is Tokico by Hitachi. Dunno what's specifically dead on the OE board, so I may do a post mortem unless someone just wants the old board to probe it for their own experience.

I got the base height trim set with the height sensor as well. Service manual says the system should maintain a base air pressure of 10-22 PSI, so I kinda just did that by feel against the air bladders by just barely getting the compressor to engage and pump up the shocks just a bit. Manual actuation of the height sensor without the linkage attached does get appropriate compressor and vent action, so I think everything is operating as it should now.


Also did get a NOS trailer wiring harness in the last few days, so I'll see about attempting to get that configured appropriately. This car was not a trailer package car, so I may have jumped the gun as the appropriate wiring harness connectors and relays may be absent and would otherwise would have to be installed in some meaningful way going forwards.

[Kodachrome Wolf]

I love wiring. I hate wiring.



Got myself a handy-dandy factory trailer wiring harness between the interior and exterior of the vehicle. Ford must have been using some serious cabling back in the day, as every wire was 10 gauge with the exception of the trailer brake wiring that was 12 gauge. Well in the case of a "lesser" option vehicle owner where the trailer circuitry is absent, I had to make do and just use that as a stub section of cable and build a harness to do the rest.

I had asked a question prior in the electrical sub-forum, and did run with using relays for the lighting circuits.


Ugly, but functional. I had plenty of the Ford OE Bosch style 5 pinners laying around and used those to drive the signals and brake light feeds.


With regards to the first photo, I did opt to install a 7 pin connector despite presently only the functions seen on a Flat 4 being functional. The reason for that is I did run the two additional wires for the battery charging circuit and trailer brake controller feed up to the passenger kick panel. That will simplify adding the brake controller that I already have, and if I so desire, I can easily add a key-on relay for the 12v charging circuit too. The only pin not used is the reverse light feed, but that's not present on the factory trailer harness. There is a brake light feed direct that I don't have wired in (and could be used for that instead) because the left/right signal feeds also provide a brake light feed, and such as a feed is not used on a 7 pin connector. I'm certain the setup was probably designed for a 6 pin connector, but I can't say I've seen one of those in use on most newer trailers.

Anyway, the trailer I'm hauling Thursday to Raleigh only has a Flat 4, so I don't need the extra functions yet. Already checked the outputs as solid and cleaned up the grounds at the back near the tailgate harnesses. Turns out paint really sucks as a conductive surface, whoddathunkit.

[87gtVIC]

Looks fine to me. Throw that panel on and you wont see a thing.

Now you need a 7 pin to 4 flat adapter?

How does a charging circuit work?

[gadget73]

the charging circuit is just to recharge the battery in the trailer for the electric brakes. They have a cable on them that if it pulls out it locks up the trailer brakes. Usually its connected to one of the safety chains. I don't remember if its key-on only or not in stock form but its just a feed from up front to the socket, nothing at all special or fancy.

[87gtVIC]

So just 12v to the trailer battery is a trailer charging circuit?

[Kodachrome Wolf]

Looks fine to me. Throw that panel on and you wont see a thing.

Now you need a 7 pin to 4 flat adapter?

Panel fitted with all the sound deadner present muffled the relays pretty good. You have to be sitting by the cover with the radio off to hear them cycling.

The trailer plug connector features a split 4 flat and 7 pin setup, so no need for an adapter, which is what I wanted for simplicity.

the charging circuit is just to recharge the battery in the trailer for the electric brakes. They have a cable on them that if it pulls out it locks up the trailer brakes. Usually its connected to one of the safety chains. I don't remember if its key-on only or not in stock form but its just a feed from up front to the socket, nothing at all special or fancy.

Key on for the 12v charging circuit.

So just 12v to the trailer battery is a trailer charging circuit?

Supposed to be a charging circuit for an on board battery, but probably with the gauge of the wire that has to carry it all would be closer to a maintainer. Otherwise, it does provide a 12v source with the key on for anything that might utilize such a thing if the trailer supports it.

[VicCrownVic]

Marge has no sound deadener on that panel and those relays are loud, LOL. Kind of useful because it clued me in that the brake lights only come on at just about full pedal travel. I need to address that since I'm often not at full travel while coming to a stop, but it's getting to be the time of year where it's time to stop driving it until the weather gets better.

Someone (last 4 owners are all on here) had stuffed some towels around the relays... Yeah I did a pretty thorough cleaning including removing panels and cleaning stuff nobody would ever see when Marge first came to my place. Not a problem you have way down there in GA.

[Kodachrome Wolf]

Marge has no sound deadener on that panel and those relays are loud, LOL. Kind of useful because it clued me in that the brake lights only come on at just about full pedal travel. I need to address that since I'm often not at full travel while coming to a stop, but it's getting to be the time of year where it's time to stop driving it until the weather gets better.

Someone (last 4 owners are all on here) had stuffed some towels around the relays... Yeah I did a pretty thorough cleaning including removing panels and cleaning stuff nobody would ever see when Marge first came to my place. Not a problem you have way down there in GA.

I did have to add a small isolator pad of some folded fabric under the little tabs I mounted the relays on because having them solidly mounted directly to the panel sounded like someone unlocking and locking a door with the switch. They were incredibly loud in regular operation.

Brake light switch was replaced several years ago due to similar issues. Mine would usually just kinda flicker for the first 50% of pedal travel before staying steady.

I also cleaned under that panel while I was there. Removed the old Premium Sound amp since that's no longer operational. Really liked how those were installed with two self tapping screws right through the body and exposed to the environment. Had to clean up a bit of surface rust prior to filling the holes. There was also a lot of sand (?) or some fine powdery dust between the outer body metal and the inner body. Vacuumed it out, but it was like an inch or two deep. No idea where it came from or how long its been there. I couldn't find any holes in the body that would have allowed anything to build up there.

[gadget73]

the relays in the Towncar are in the trunk, and I can hear them operate through the rear seat.

[Kodachrome Wolf]

Tomorrow we're off for Raleigh, NC.

Gonna terrorize the Carolinas with this setup:


But with more tow mirror and functional trailer wiring:


Very old fashioned, but should prove useful. When originally checking the trailer hookup, it became obvious how poor the regular side mirrors perform for towing duties.

I slammed a transmission plate cooler on as well while getting the wiring done. Came from Nick's long since dead Explorer engine donor since the transmission was working well in that vehicle and not puking metal through the system. Those claimed a 5000 LBS tow rating, just like our cars when equipped with a 302 and automatic transmission.

I did flush it Kooler Kleen and tossed in a bottle of Lubegard ATF protectant. Not much for "mechanic in a bottle", but Lubegard always has seemed to work quite well in any transmission I've added it to. Probably one of the few brands I can trust when it comes to actually helping make things keep working properly and not just being snake oil.

Definitely won't be setting any speed records tomorrow, probably the most the wagon will see is about 65 MPH since I just plan on keeping it locked in 3rd gear and I'm not trying to wind the motor up above 2500 RPM for cruise speed.

[87gtVIC]

Yep. That’s a look alright. And I like it!