Hi All

1989 shorty, 3.0L - lately, last few months, when it rains, Im getting some sort of short where the door ajar light on the dash stays on, even though all my doors are closed, but this kills power to my windshield wipers...

Sometimes, I can drive around for 4-5 mins, and it will go away, and I can put the wipers on... but this sucks since I need the wipers in the rain, and this is when the problem happens...

Anyone point me to the right place? The switches for the doors all close, because I don't have the overhead light on...

what would cause this?

Thanks so much in advance - it's raining here and I hate to drive with no wipers!!

 

check the fuse box for moisture leak and corrosion.
pull it off the sheet metal and examine the back side

any leaks from windshield down into dash. examine with flashlight looking up from floor boards.

my Aero wiring diagrams are too new, '96.
try the Autozone site.
may be a common ground point used by the door ajar relay and the WW motor circuit, corroded and loose.

my Aero is the most electrically reliable vehicle I've ever owned and it's spent most of it's life parted outside in the NW rain.

 

mine was too, but the wiring is almost 25 years old.

I found the problem - at least I think I did - Bad Ignition switch... when I put it into AUX (all the way left) - never a problem, unless I turn it too far...

in the RUN position, it's touchy - never shuts the van off, but if I move the key with the play it has there in run, it will activate the short while van is running, then if I turn the key all the way to the farthest point in RUN, the short is gone usually...

How hard is this to fix, say replacing the switch, and /or the whole module? would I need to have it re-keyed? (this is an 89, before all the chip keys)

do I need to pull the steering wheel?

Thanks to all!

 

no need to pull the steering wheel!!
there is an access hole in the plastic cover, exactly under the ignition switch, stick a pick tool up the hole to push a pin upwards, and the entire ignition switch comes out by pulling it as you push the pin. Not easy the first time but keep trying.

If you have trouble reinserting a replacement ignition switch, you will have to remove the upper and lower plastic halves of the steering wheel column covers to get it right. (3 phillips screws on the lower half of the covers).

before you remove the switch, go to eBay and type "ignition switch aerostar" (without the quote marks), and you will see many replacements with two new keys included. Make sure you go through all the listings since there are many prices for the same part and some have Free shipping, and to find one for your model/year; the Free Shipping listings are the ones I look for when buying at eBay.

if you don't like eBay, (some people don't), go to google and type the same thing and you will see thousands af advertisers selling these switches. You can also check with RockAuto who others recommend here, but be aware that RockAuto charges for shipping.

 

Thanks - I actually thought I remembered a recall on this exact problem, and I don't think I ever had it taken care of, since it was in 1996, and by then I wasn't paying the dealer to do anything:

Recall Date:
APR 25, 1996
Model Affected:
1989 Ford Aerostar
Summary:
THE IGNITION SWITCH COULD EXPERIENCE AN INTERNAL SHORT CIRCUIT.
Consequences:
THIS CONDITION COULD CAUSE OVERHEATING, SMOKE, AND POSSIBLY FIRE IN THE STEERING COLUMN AREA OF THE VEHICLE.
Remedy:
DEALERS WILL REPLACE THE IGNITION SWITCH.
Potential Units Affected:
7900000
Notes:
FORD MOTOR COMPANY


Read more: 1989 Ford Aerostar Recalls & Problems - Motor Trend Magazine

is this the actual switch, or are they taking about the thing this would connect too as the switch? looks like there is a flat plastic plug that is related here...

Iam assuming that the cylinder itself has metal contacts too? I guess I'll know more once I pull it... but wish I had a diagram of that unit and what it connects to...

Thanks

 

you're welcome and yes I remember that news, a number of Aerostar catching fire was traced to the ignition switch. (after that news some people actually set fire to them!).