I have a 90-91 Ford Aerostar Extended XL with the 3.0 V6. The Anti Lock Brake light stays on and the rear end locks up dangersely easy. I have disconected the Delta P stitch on the master cylinder, witch took care of the brake light being on but the Anti Lock light is on and the rear breaks lock up real easy and Is a real hazard to me driving when I hit the breaks not evan hard. Any Knowlege on this will help me and are there any way I can get computer codes with out a expencive code reader.

Thank you Very Much

Jeremy Vickers

 

Hit the "search" link at the top of this page and do a search on this subject. There have been numerous postings with instructions on pulling codes without a scanner. Most have been within the past 3 months but you may have to go back further to get them all.

 

I did do a search and did not find the information i am looking for, I know on some cars you can find the computer connectiion and jumper it with a peice of wire and turn on the car and the dash lights will bliink a certen way and you can figure out what is wrong. Is this posibile on an 90-91 aerostar?

 

Had the same problem a few years back on a Bronco II. I bought the car used from a Ford dealer. Before I got it I told him it needs new brake pads on the front. He put new ones on. A couple of months later I hit the brakes going down a slick snow packed hill. The antilock light came on. A few days back on again & the rear brakes were acting a little screwey. I checked out everything and after trying everything I bled the brakes. I went thru a couple of containers of brake fluid. I cleaned out the brake master cylinder & put in new fluid before I started. That fixed the problem and no problems the last three years. The Ford dealer when replacing the pads had pushed old fluid into the master cylinder when compressing the brake wheel cylinders to remocve the pads. He than forced the old dirty fluid back into the system when bleeding the system and seating the wheel cylinders against the brake pads & rotors. Hope this helps.

1989 Bronco II XLT
1993 Aerostar AWD XLT
1992 F150 XLT ext cab
1974 Ford Maverick

 

Attached is the procedure someone sent me when I had a similar question. I didn't use the procedure, but I would assume it works.


Make a jumper wire about 2-3 ft long with a small alligator clip on one
end, bare on the other. To locate the RABS test connector, look on the
inside, drivers side, above the kick panel. You will be looking up at the
wire clusters between the back of the fuse box and the firewall. Located
about midway is a squarish, open connector fitting with a single black
wire with orange tracer going to it. It is probably held onto the wiring
harness with a plastic anchor. You don't have to pull it loose, just twist
it around so you can see and access the connector spade tip. Attach
the alligator clip to the spade tip. The RABS
system will hold only a single code at a time. You need to recreate the
situation that causes your brake/antilock lights to come on. If they only
come on when driving, then drive it until they appear. The code can only
be read after the error has been detected AND THE ENGINE REMAINS
RUNNING. Shutting off the engine will erase the code from memory.
Once the lights have come on and the engine remains running, take the
bare end of the wire and ground it temporarily to the ignition switch or
other good grounding point. Just hold it to ground a second then release
it. The yellow antilock light will begin to flash. Usually a series of quick
flashes followed by one longer flash. It will then repeat this over and over
until the ignition is turned off. Count all the flashes including the long
one. I.E. two short ones and one long one would be an error message
"3". There are codes from 2 through 16, each with a specific meaning.
The Chilton's manual does contain the testing procedure as well as a
description of the codes. Or, you can post your findings here and get
further help. Finding the cause of these RABS problems is the most
maddening thing I've encountered. After countless hours and parts
replacements I am still not 100% certain what the root cause really
was.

 

Is Bleeding the rear breaks like bleeding the front? I have done front breaks on a differnt car but I have not look thourghly back there but I did put new drums on this summer.I will bleed the breaks tomarrow.


Thanks for your help

 

On my Bronco II & F150 it was no problem bleeding. I started bleeding the side that is the fartherest from the master cyl.You will get all kinds of sludge out.It should be like bleeding the front. Good luck. Careful you do not break the bleeder screws or round them off.

 

[font size="1" color="#FF0000"]LAST EDITED ON 31-Oct-01 AT 11:27 AM (EST)[/font][p]When the brake/antilock lights appear that is only an indication the RABS system is no longer functional. At that point you have a regular braking system. The fact that your rear brakes are locking up is not due to the RABS system but something else. Unless you are braking heavily for stops, your rear brakes should not be locking up that easily. As the rear drums were replaced earlier, could the shoes be reversed (leading/trailing edges) or the adjusters too tight?

 

The story with the light is last year the break light and the ABS light would come on avery once in a while. Some times just the Break and then the abs, but one day they both came on and would not go off. but on cold morning they would not come on until i hit the breaks after going down the road a ways. So I found this online document that said the Delta P switch is more likly the problam, there is no documentation on this part in the repair books i have, so I disconected the switch witch moniter break fluid pressure in the master cylinder. This took care of the break light but the ABS light stay on now un less its a cold morning and then after 3 minuets of driving it comes on.

 

Hate to say it, but it sounds suspiciously similar to my own experience, particularly being off when cold intermittently, then finally permanently on. Even with the diagnostics offered by the Ford shop manual, I could not pinpoint the root cause, as fixing/replacing one thing would cause other error codes to appear for something that was supposedly working just fine the day before. I replaced the RABS valve assembly with a rebuilt unit ($117 + core deposit) and scavaged another RABS control unit from the local boneyard ($20). Fired it up and both lights went out and stayed out - for one day. The following morning when I started it up, the red brake light came followed by the yellow anti-lock. I cussed and swore a blue streak. The error code said the reservoir switch was bad. I bypassed it, both lights went out, hooked it up and both lights would come on. Pulled it off, left the bypass jumper in place and drove around like this for several weeks. One day when changing oil, I stuck the connector back on. No lights! Been driving around without any problems ever since. I still can't say for certain if this is a single or multiple source problem. It's fixed and I ain't agonna risk disturbing the evil electronic gremlins that dwell within.

 

I discontected the pressure switch a while back and that took care of the red brake light I am fighting the ABS light now and I am trying to do it cheaply as posible

 

The two lights are inter-related through the RABS control unit. In other words, certain problems with one will activate both lights. To track the problem down, you need to pull an error code with the procedure mentioned in an earlier post. In the meantime, the first place to begin is with the parking brake switch. Park the van in a garage, darkened area or evening. Put the connector back in place and start engine. If the red brake light is off, pull up the brake handle and see if the red light comes on. If the red light is already on, do the same thing but watch closely, to see if the light becomes a brighter red. If not, your switch is sticking, broken, or disconnected.
Also, as you gather the error code, note whether the two lights come on simultaneously or if one light briefly preceedes the other.

 

The Light never came on then I pulled the parking brake. It never has.

 

The switch is stuck. Remove the rubber boot from the parking brake handle and put some lubricant on the switch. You may have to manually pull it up and down a few times if there is corrosion or gunk limiting the switch action.
Also, check to see your brake lights are operating, i.e. no burned out bulbs. After this, you need the error code to go any further.

 

Where can you buy just the switches that go in the master cylinder for the 91 Aerostar Ext? Everyone wants to sell the entire unit.