ABS Light flashing -
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ABS Light flashing -
I know this isn't a new topic and I have done much searching but cannot come up with a logical solution. I do need help. 1996 f150 supercab, 5.0, 4r70w trans, 115,000 miles. One owner - me. ABS light on dash flashes steadily, cannot shift out of park, brake lights do not work, cruise does not work. I replace fuse, start truck and light is off for a couple seconds and starts flashing again. Same symptons as above. Pressure switch on top of master cylinder was leaking and melted the plastic 2 wire connector causing a short, I thought. Replaced the pressure switch and the the connector - Same thing, engine runs for a couple seconds and blows the fuse. Don't even have to step on the brake pedal - blows fuse on its own. I have not had codes read at this time. Has anyone had the same problem? BTW - if I disconnect the switch and leave the connector hang freely and replace the fuse - all is fine except for the Cruise control, it still does not work. Brake lights work and no ABS light flashing on dash. I checked the new switch for a dead short - was good. Also tested the connector pins - showed no short. Any ideas/ suggestions??? Thanks - Jerry
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From: Central NY
By any chance to you have a friend with a simular truck and can try thier rabs module?
The short might have caused another short in the RABS module itself. Pull the connector on the RABS and see if the fuse still blows.
Thats about all I can think of at the moment.
Keep us posted,
Popa Tim
The short might have caused another short in the RABS module itself. Pull the connector on the RABS and see if the fuse still blows.
Thats about all I can think of at the moment.
Keep us posted,
Popa Tim
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From: Pulaski, TN
well i don't know much about the abs, i have a problem with mine that i can't fix, but it sounds like you have a shorted wire somewhere, so all i can say is check the wiring, maybe the test wire inder the dash on the passenger side, it should be an orange and black wire in a connector.
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Good advice. I hadn't thought about pulling the wire on the rabs. Don't know of anyone close enough to switch modules. I'm going out of town for a few days but will be back next week and will start checking out things again. Thanks for your inputs Popa Tim and Jim Bob. Any and all ideas are welcome. I will most definately keep you posted. Jerry
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Hello, it's me again. After reading your inputs I started thinking about how I checked for a short in the 2 wire harness that connects to the pressure switch. I was measuring for a short between the 2 wires a green one with brown (I think) stripe and a black one with a orange stripe. I went back out to truck and measure the harness from each wire to ground. The green wire showed nothing at all but the black w/orange stripe showed almost a dead short - had like 2.4 ohms of resistance. I'm thinking as Popa Tim suggested, it might be the sensor on the differential that is shorting - - does that make sense???? Jerry
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From: SC lowcountry
The red /White wire should have 12 volts on it at all times when fuse 13 is installed; Teh Black/yellow wire should go to the cruise control servo/ amplifier assy - I would think it should not show direct ground unless something is shorted in the cruise amplifier. Hope this helps. The differential sensor is a different input to cruise control.
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95X15, I haven't found a red and white wire but I thank you for the information. Now that I'm back in town I'm going to start my search again. I will keep posting what I find out. Thanks again. Jerry
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Okay - - found time today to do some more checking. The black w/green stripe wire from brake pressure switch goes to the cruise servo and measure dead short to ground. The bright green w/dk orange stripe wire from pressure switch goes to fuse #13 and is always hot. I measure the switch again across the two pins coming out of the switch and they measure a short between themselves but not to ground. Does anyone know if they should measure a short between themselves - I don't think they should cause that seems to be what is popping the fuse every time I put the plug on. It is a new switch by the way - - but I know you sometimes get a bad "new" whatever. If they are supposed to measure a short then I have a problem somewhere else. What about the black w/green stripe wire going to the cruise servo - should it measure a short to ground? Thanks for any additional help. Jerry
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From: SC lowcountry
The pressure switch is normally closed (without brake pedal pushed) and always has current thru it, although small in normal conditions - when brake is pushed the switch opens and deactivates cruise. I would think you have a bad servo or amplifier for cruise. Suggest taking cover of servo off and making visual inspection of internals; if bad look to a junk yard for a replacement.
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95X15, thanks for the info. I just came back in from making the internal visual inspection of the cruise servo. It looked very clean - all plug in contact points shiny and clean also. The circuit board looked like new with no dirt, corrosion or burn marks anywhere on it. Now another question - - will the switch read open without the hot wire attached and the brake pedal pushed? I would really like it to be the switch but I am gonna try to find a servo at the junk yard. I know where there is a 94 with cruise so the servo might be the same. Thanks again for all your help. Jerry
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From: SC lowcountry
The switch is normally closed - will conduct when no pressure is applied to switch port. I missed a wire color change coming thru the bulkhead connector from red/white from fuse to light green/red coming out of bulkhead to switch (12v) thru switch to black/yellow wire going into the cruise servo amplifier.
Since you said you had searched the forum I figured you had seen the fact that this switch is the subject of recall for vehicle fires on later F150's - the recall harness I have seen probably has a fuse/fusible link in the harness. I personally would not play around with this particular fix. It is possible one of the parts suppliers may have just the amplifier available. Good luck.
Since you said you had searched the forum I figured you had seen the fact that this switch is the subject of recall for vehicle fires on later F150's - the recall harness I have seen probably has a fuse/fusible link in the harness. I personally would not play around with this particular fix. It is possible one of the parts suppliers may have just the amplifier available. Good luck.
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Fixed. Thanks to all for the tips and help you provided. The pressure switch was good, I checked it with pressure and no pressure and it worked just like 95X15 said it should. I talked with my ford dealer and the parts guy said the electronic control module on top of the servo is usually what goes bad. They do not sell that separately so the complete unit was $297 and change. He told me all f150s from 92 to 96 used same module. I went to a local junk yard and found a 94 - purchased the electronic module for $35. Put it on and - wah la !!!! No more blown fuses, no more shifter lockup, no more abs light flashing - - I'm a happy camper to say the least. Thanks again to everyone for the tips - ideas and help. Jerry
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Maybe this is my problem too? I don't drive my truck very often at all, maybe twice a month... A couple months ago, my cruise went out and I have been trying to figure out the cause. Thought I had pinned down to the steering wheel controls. Well I haven't had the time to mess with it recently so I have just left it.
Well I used the truck about a week ago to pick up some furniture and the ABS light starts flashing... So I check the #13 fuse and it's blown. I replace it, and as soon as I do so it blows the new fuse. Even with the truck off it will immediately blow the fuse.
Guess I'll start looking for the electronic module in the junkyard.
Well I used the truck about a week ago to pick up some furniture and the ABS light starts flashing... So I check the #13 fuse and it's blown. I replace it, and as soon as I do so it blows the new fuse. Even with the truck off it will immediately blow the fuse.
Guess I'll start looking for the electronic module in the junkyard.
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well, looks like that is the problem! Went outside and unplugged the cruise, put a new fuse in and everything is fine! Man I love sites like these, saves you hours and hours of time looking through the manuals and troubleshooting! Off to the junkyards!
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I'm a liar!!! It was the cruise control sensor on the master cylinder which is responsible for vehicle fires! I pulled the haness off the switch and the plug was dripping with brake fluid. I'm glad that fuse kept blowing or else I wouldn't have a truck!
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