ABS lights on-no boost

B

Blown6

Registered User
I have a 90 SC and the ABS light and red brake warning lights are on all the time and there is no boost,the brakes feel like standard brakes which is not very good.If anyone has come across this and knows what it might be,please feel free to post your thoughts.
 
When you have both lights on on the dash like that , your going to have to replace something on the ABS or replace the whole unit.
There are alot of parts for sale in the classifed board of this site and the prises are'nt that bad.

If your gauge is not reading boost it could be that it is unplugged from the back of the gauge on the dash Or at the engine.

Kurt Sr
 
You need to determine if the ABS pump is running at all like Tbird 88 suggested.. If not, it could be the pump relay or the pump motor. You can do this by simply turning the key on but engine off and pressing the pedal a couple of times and listening.
 
the manual says start with measuring the resistance of the LF wheel sensor, compare that reading with the other sensors(in ohms), should all be with about 10%. The other option is to get the codes read
 
Thanks for the input,I have already tried to retreive codes but that doesn't seem to be getting me anywhere.I realize that I have to replace something,I have already replaced the pressure warning switch and pump relay but that didn't repair it,I also tried an abs power relay but it didn't change either.
The pump runs briefly when the key is turned on which is a good sign of operation.....I just came in and the the whole drive was light free and I had good brakes until I got into my driveway,then they both came on and the pedal got hard-I'm stumped for diagnostics at this point.
 
then they both came on and the pedal got hard-I'm stumped for diagnostics at this point.
Click to expand...
I had the same problem, turned out to be the BROWN ABS fuse on the passenger firewall. You can get a new one from NAPA for around 20USD maybe less. It fixed my problem when the same thing happened to me 4 months ago.

Cheers,
Calvin
 
Maybe the accumulator...

Had the same problem in July this year. Both lights would come
on while braking, then go off. If you can hear your HP pump run,
then try starting the car and wait till the lights go out.
Then push your brake pedal down firmly like you're going to stop,
then let up, you should be able to get three cycles out of your
accumulator before the HP pump recharges the accum. Mine was coming
on every time I pushed the brake pedal. I changed the accum.
and it fixed everything.

Prior Reman. sells them new, shipped UPS for $106.97 Their number is 1-800-444-4821 Email me for instructions if that's
what you need to change.

J.
 
in his first post he says they stay on all the time, if they only go on when he hits the brakes then I'm betting 100% on the accumulator, if hes in B.C. I just removed my accumulator for no reason and replaced it...dont ask:D. Yours for 50cnd swap, since I have to return a core.
 
Start with the relay, it is the brown one on the passengers side fire wall. With the ignition switch in the run position U can just remove it and jump it. If the pump runs change the relay. If not get back to me U can E mail me.
 
Probably not the accumulator

The sudden loss of braking power is most likely an electrical problem. The accumulator will degrade over time and when it goes, the brake/anti-lock lights will start coming on and going off.

Oh wait.. scratch all that....

After going back and rereading Blown6's posts, I'm fairly sure it IS the accumulator. Blown6 sounds like he let it go on for so long that its just plain out not holding any sort of a charge. I'll bet the lights have been going on/off for quite a long time, haven't they? :eek:

What we really need to know is how often the pump runs. And one more note, a failed accumulator won't throw a code. Nor will a failed pressure switch, nor any of the relays.
 
Thanks for all the input on this one,sounds like it is probably the accumulator.I haven't had the car very long so I don't know how long this has been going on.In the last couple of days,after starting the car, the lights would be out and I would have good brakes for a few stops,then they feel hard and the lights come on again.The accumulator , according to what it is supposed to do seems like it will not build and hold pressure(does that make sense?).Hey AaScLoWn,I'll buy that sucker of ya if we can get that arranged,that would be cool(you said don't ask but why did you change it-if it wasn't neccessary then I guess the one you have is good......you don't have to answer that.
Peace..
 
yea I got your mesage, both of them:p . I bought it and thinking changing it would make a difference in pedal feel eventhough it felt fine and no lights. Dont know why but the prior unit has a stiffer feel than the original(was thinking of putting the original back):rolleyes:. It doesnt have the pedal feel like the OEM Ford unit. The factory also had 2 styles, the longer and smaller length fitting. After-market is the smaller length. If I had to do it over again I would buy OEM, feels like I'm driving a truck:(
 
You must log in or register to reply here.
Back
Top