Replaced the passenger side headlight bulb last week. Next night, after 40 minutes of use both headlights started to flicker. On and off like strobes. No other lights are affected. Tail lights, dash lights, and trailer lights are working perfectly. This problem reappears with each use of the lights. Once it starts it just goes on and on until the lights are turned off for a period of time.

Any idea what causes this?

Thanks

 

Most problems with intermittent headlights are related to the headlight switch. Ford engineers in their infinite wisdom built a switch that cannot handle the continuous current draw through it. Over time it begins to arc, which produces heat. This heat further damages the switch. Eventually the overheat cutoff is triggered. The headlights will come back on when the switch cools down enough. The solution is to replace the switch, an possible the harness that connects to it (Rockauto should still have the harness). Then install a relay harness to handle the current, so that the switch does not have to carry that much load. The harness has the added benefit of making the headlights brighter too.

Here is the harness you need, very easy to install. Don't worry that the Aerostar is not listed, I use this harness on my own van.
Upgraded Headlight Harness for 94 to 04 Ford with 9007 Bulbs

 

Thanks for the tip. I noticed the heat in the switch this AM.

 

SC-I just changed mine for this very problem yesterday. It is an Eddie Bauer with the head-light dimmer delay. What does that mean? This special head-light switch is a whopping 161.00 at Auto Zone as compared to just 14.00 for a regular one in a regular Aerostar. I don't need the special delay in the relay so I just installed the regular one. Same connection. Instructions: To replace is really simple now that I've done it. You won't find this 1st step in a Chiltons or Haynes. The plastic black ****. Van door open all of the way so that you can hold your head up close. See the notch cut out of the back of the ****? It has a spring clip in it. Take a miniature standard tip screwdriver. Hold the tool next to the metal stem then simply apply pressure and pull up on the clip/then **** with pop right off. Now you have to get to the area at hand. Start off by taking the bottom panel off under the steering wheel. Screws hold the dash panels in place. They are 9/32nds in size. Under the air duct next to the drivers door, to the right of the dash by the radio. Last but not least "DON'T FORGET THE TWO SCREWS AT THE VERY TOP OF THE DASH". I forgot and almost broke the dash by force. You will be looking straight at the switch at this point. It is held in place by 2 screws (remember all screws are 9/32nds). Simply tilt to one side and pull out slowly. It has a large black connector attached. It has 2 ea ears holding it in place. You don't want to force it or the feet will break off. What to do. What I did is this. Take a medium sized screw driver and place under each ear. By doing this you can just simply wiggle the connector off without breaking it. You will notice as you are taking your new head-light switch out of the box is that it doesn't have the pull **** rod in it. Before you start cursing the parts man look under the switch body. It has a "push" pin button on it. Push in on the detente as you are pulling the triangle sized rod out and and place it into your new switch. Well, I don't think I've left anything out. Good luck.--Boz

 

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i'll third the upgrade of adding relay power to the headlight circuit.
can make your own harness. couple 30 amp auto relays and 12 ga wire.

lots of writeups on the web, google

 

Nice pics inall of the books plus the pull up on the computers at the parts stores. Only problem. Doesn't talk about the **** removal. People usually end up twisting and breaking the shaft.

Follow how I explained the process and all should be fine.

Photo doesn't even show that the dash panel is still on the van. Switch doesn't just "come out". Push up on spring clip-all should be well. Don't forget-you have to reuse your own pull out shaft.

 

Some relay information that might be helpful. I plan to add one when I install fog lights. Catalog

 

Thanks for the responses. I've picked up the switch and will replace tonight. I'm going to put off the wiring harness for now. We are the original owners, she has 334,000+ miles and if (when) the engine (original, burns 1 qt. of oil every 1,000 miles) were to go we might not invest any more in her. But then again...

 

*gasp* You would get rid of a beloved Aero? It's just not done here

 

The problem with making your own harness is that after you buy the wire (you have to get more than you need), and the the connectors and stuff, plus if you don't already have a voltmeter, and a soldering gun, etc. You spend about as much or more versus buying a pre-made harness. I was very impressed with this harness. I had it installed (including routing the wiring and all the prep and clean up) in under half an hour. You just take your original headlight plug, plug it into the harness instead, rout the other end of the harness to the other headlight, plug it in, connect the ground lead to a good ground, and connect the positive leads to the hot side of the starter relay. You can screw or tie the relays to the inside fender, but I just left mine loose. Its really not going to save you much of anything to do this yourself unless you splice all your connections and already have the wire anyway, and already have the soldering iron or gun and materials.

 

Most likely will purchase the harness. Now that I'm watching for it I was surprised at how hot the new switch was after installation. On the plus side the new switch went in without any drama. It would be hard to part with the old thing. It is my daily driver (78 mile round trip commute), motorcycle trailer tow machine, and any thing else we can through at it. Are all 3.0s as durable as mine or have I been very lucky?

 

there are european type relays with "build in" fuse socket...



ore sockets for relay with fuse




You can made harness yourself, it is easy. No expencive tools. And you can use ruther thik wires (2.5-3 mm2) to have no voltage loss.....

 

I also advice you to get German Hella H4 headlamps of old WV Eurovan/Transporter.



But sime of them had round headlamps (fit Freightliner Century)...

EU headlamps are much brighter

 

I have Bosch H4 200mm headlights on my van now. Yes, they are brighter, and have much better pattern. That was a drop-in replacement for pre-92 Aeros. For 92-97, you will hav to change out the light housings and structures aroung it, as well as the wiring.

For convenience, it's hard to beat a wiring harness made just for your type of lights. But I made my own harnesses anyway. My problem with most premade harnesses is related to what Pablo mentioned; most of them do not use the heaviest gauge wires available, you're still using the stock wires from the relays out to the the lights, which can be as thin as 16 or 18 gauge, and you're adding another set of friction-fit connectors between the power source and the lights. While installing a relay cuts out the sections of thin wires going through the switches, it's still not quite as good as having 12 gauge wires going from the relays right up to the light sockets. Also, few of them have truely waterproof construction. In one of my projects, I was replacing the stock lights with HIDs in E4 housings, so I had to make my own wiring harness. Furthermore, I had to re-wire the lights to keep power to the low beam when I switch to high beam, because of the HID ballasts.

 

about 92-97 aeros... yeah! '86-91 light struckture fits well and it is available on JYs nearly for free....