Hello All--

Long time no post, but for a good reason! 1994 Aerostar E4WD Ext. is running great! have done some maintence on it (brakes, tensioner, oil change....), but end of the month we are going on a trip (800 miles one way) and Hubby wants to take his 27 foot sailboat with us!

Aero has the factory installed tow package, and the "install a hitch" guy just left the house. Got a Class III put on it, just to be safe, and the wiring was suprisingly in great shape and was a breeze to wire up. Tommorow the Aero goes to the tranny shop to have the tranny oil and filter changed. He's also going to check out the driveshafts and U-joints while he's under there. There are some other minor things we want to get done to it (fix the air conditioning, clockspring--so the cruise control works, etc...)

BUT!!! Is there anything else that I am not thinking of that we should do before we make this trek!!!?????? Please post any and all wonderful advice you can think of!!

Thanks so much!

the Cowgirl Mechanic

 

The biggest transmission cooler available comes to mind. Good luck with the trip.

 

I'd make REAL sure the trailer's brakes are in primo condition and working well.

Steve

 

Ditto.


I would also make sure that the Aero Brakes are in Primo condition along with the E-Brake.)

 

You should or could also forget about the A/C if you use it when you are pulling like that you have a good chance of smoking your transmission.The biggest tranny cooler is still a good idea even if you dont use the A/C

 

[QUOTE=yendor]You should or could also forget about the A/C if you use it when you are pulling like that you have a good chance of smoking your transmission.The biggest tranny cooler is still a good idea even if you dont use the A/C. I would also use my foot so you can tell how far you are getting your foot in to it,with the cruse you cant tell how hard it is working

 

Check if they wired the trailer connector to actually use the trailer towing module.

I wrote a lot on this in this thread, much of which I now find less than comprehensible, but the gist is that if you have the Ford towing package, you have a towing wiring module that is completely inactive until it is activated by grounding a pin. Ford's adapter harness (sold separately, and NLA AFAIK) does this when you plug it into the two connectors under the bumper, but you can build your own harness (read that thread, it tells you how) or can cut and splice your own connector on.

My main point is that you are much better off utilizing the factory tow wiring module if present, than trying to drive the trailer lights off taps from the normal body wiring, which isn't designed for it.

You can tell if the trailer towing module is activated if you can hear a faint clicking from the left rear when you have a turn signal on (it's a relay clicking, that's powering the rear harness, but only when it's active).





Regards,
Al S.

 

I am happy to have this info, even though I will never pull much more than a trailer with my lawnmower. One thing I noticed was that you show the left and right brake lights and turn lights on the same wire, and mine are two different lamps. (brake is a red one and turn is amber.) Is there a different diagram for that? I have seen a couple of Aerostars locally that did not have the amber turn lights on the back.

 

In the past, all domestic vehicles used the same filament at the rear for brake and turn.

Almost all foreign cars use a separte (amber, usually) bulb for turn signals. Many if not most domestic cars now do this as well (the "Euro" look).

Almost every trailer on the road uses the old system.

One of the functions of the factory tow module is to combine the brake/turn functions out to the trailer. On our Aerostar, it's done with discrete relays. The converter module you can buy for non-factory tow module rigs is four low-voltage diodes to do the same thing.

You can't merely connect the turn and brake wires together, because when you'd activate a turn signal, both brake lights would blink. Hence the diodes. It's funny how much money those modules cost, considering they're just a buck and half of diodes plus some colored wire and a label and bubble package. (I soldered up the same thing in 1979 to my mother's Volvo, cost me about $3 from Radio Shack for four diodes.)

To summarize: the factory tow module has inputs of left turn, right turn and brake (three wires), to feed four filaments, and outputs those same signals on two wires for two filaments on the trailer.

If you have a trailer with separate filaments for the turn signals (separate from the brakes) then you can't use the factory tow module, because it does not provide the separate outputs.

Regards,
Al S.

 

Well, the tranny fluid and filter change went great! The tranny shop pro said everything looked tip-top and of course to tow in D not OD!! He said to keep an eye on the engine temp gauge and take a break if things start to look like they are running hotter than normal.

I will definetly look into putting a bigger tranny cooler on the van, and the Hubby agrees with you'all about nixing fixing the A/C for this trip. So I'm going to go shopping for a fan that will plug into the ciggy lighter!! I really don't want to bake if the weather turns warm again!!

The clock-spring is a must fix, cause the Hubby has a bit of a "lead foot" and making sure the cruise control works will keep him out of trouble!! We figure its a "cheap" fix compared to the potential ticket he might get!!!

I am having problems with the rear brakes, so if you can help, please reply in my new thread "Rear Wheels Draggin'-.."

Thank you all for your help and advice!!

the Cowgirl Mechanic

 

I do usually tow my 2 horses with my 1993 4.0l extended Aerostar, and am doing great. Since I am planning on getting a new trailer for 3 horses, I am concerned about 2 things:
a) the allowable tongue load for my Aerostar, and
b) The appropriate shocks for the job.

You might want to check the shocks especially, and also see how heavy the tongue load of the trailer actually is.

Have a good trip!!
Axel

 

OK! New problem.....short story is after much frustration, Hubby checked the connector off the back of the van, a 6-pin, and found that the pin for the running lights had low volts and .1 amp. Suffice to say, that is not enough juice to run the lights on the boat trailer!!.... Now the lights (same lights) work fine for left and right turn signals, but no running lights......any suggestions?? Our temporary solution for the present is to get some battery operated lights, but if the problem can be fixed properly, quickly, and CHEAPLY....well then we'll do it, but we are leaving for our trip this coming Wednesday......Yikes!! Not alot of time, I know, but originally we thought the problem was faulty trailer wiring...that wasted some time, chasing our tails--so to speak.......

Oh yeah--correction on the boat size--its 17 feet, not 27 ft......seems like it's bigger to me!!

the Cowgirl Mechanic

 

I would change the fuse first. Once on my van the fuse looked fine, but it had a hairline crack. Without loads, it reads 12V but as soon as you put on a load, it drops to a few volts. It's a cheap try and you have nothing to lose. Also, in my younger days, my brothers and I used to drive from LA to Vegas without A/C. We bought an ice bag each from the gas station, wrapped them in towels, and embraced those icebags for the entire trip. Worked great

 

Ok.... where do I find the fuses in this Aero!?!?! I've looked and even read some posts on trailer wiring. One poster said he found fuses, specifically for the towing wiring, in a rear cubby behind an access door. I've checked BOTH of my rear cubbies and there is no access door. Is there another cubby that does have a "secret" access door for these fuses or are they with the other fuses for the van (which I cannot seem to locate!!).

Any help would be greatly appreciated!!

the Cowgirl Mechanic

 

Trailer wiring faults are almost always bad connections and missing grounds (same thing, usually).

First, do yourself a huge favour and run a separate ground from the van to the trailer. Just temporarily. You would not believe how many problems with trailer wiring come about from missing ground connections. I use a std battery jumper cable, one end to any handy bolt on the underside of the van's hitch setup, the other end you have to try to find someplace on the trailer that has exposed metal, sometimes not easy. You cannot rely upon the hitch to carry ground, it won't work.

The symptom you describe could be a missing ground, with the turn sigs working by grounding back to the van via the taillight filaments. The turn sigs wouldn't be as bright, but they'd work. Until you turned on the taillights, and then nothing on the trailer would work (probably).

If you've got turn sig power but no running light power, and are using the factory tow module, then its fuse is OK and you have a wiring problem or module failure. You can tell if you are using a factory tow module by looking for two under-car round connectors directly above your hitch. Both will have wires coming from them, and at least one and possibly two wires will run from one connector to the other! (See my pic of this upthread).

If you're not using the factory tow module wiring, then looking for the tow module's separate fuse won't help you.

That said, I've blown that fuse enough times that I've seriously considered extending it to a place where it's easier to get to! If a short occurs in the trailer's wiring, you have to change the tow module fuse (if you are using the tow module), and I've borrowed enough old trailers to have to do this a number of times.

From memory, the blade fuse is on the side of the tow module, which on the shorty is underneath the jack in it's stowage compartment at the left rear. My extended van keeps its jack under the floor instead, and doesn't have a tow package (so no tow module), so I can't tell you where it is on the long ones.

-----

I'm assuming you're not using the tow module (third-party installers avoid them, too much thought involved to get them to work quickly, which is what they do for a living: take your money quickly), and your trailer wiring is tapped in to the std taillights harness, so the van's std turn signal system has to power the trailer too, and there's a aftermarket converter module somewhere to convert the separate turn/brake power lines to the trailer's combined system. If the van's taillights work but you have no power to the brown wire (that's the color of the industry-std flat four-wire connector; ignore me if you've got the small round 4-pin or the larger 5-7 pin connector) then you have a wiring fault or aftermarket converter failure, and since you paid somebody to install it (I think), exercise your warranty and make them fix what they broke.

If you want to fix it yourself, and you do have van taillights working, you'll have to figure out how the installer tapped into the harness. The clean way is to use an adapter harness that plugs in to an existing Ford connector set (about $15, available from NAPA or U-Haul for the later Aerostars, but not for early ones IIRC), and provides a "tee" for the trailer wiring (again, this is for adding trailer wiring for van's without factory tow package). This will be easy to spot, as all the trailer wires will go to the same place, and that place is right behind the bumper above the hitch.

However, if you find that two wires (Brown & (Yel or Grn)) are running to one side, and one to the other side, then you have the "not clean" installation method, which is the most common I'm afraid. On the side where the two wires are running, remove the taillight assy and you'll usually find two blue Scotchlok-style tap connectors that are the actual line taps. Find the (usually) brown-for-taillights trailer wire and figure out why it isn't making a good connection to the wire it has tapped.

That's trailer wiring repair in a nutshell: correcting other people's poor workmanship, or corrosion related problems due to improper installation or other people's poor workmanship.

Regards,
Al S.