Antilock light

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stupidgeek

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#1
I have an 86 325es and the antilock light is on all the time. It used to go out until I had to jump the car and accidentally left the ignition on when hooking up the cables. STUPID! [?|] STUPID! [?|] STUPID! [?|]

Anyway, the light is on all the time and the antilock brakes don't work. I'd bet it's the control unit but I'm not very lucky at betting. Has anyone ever had to replace this unit, how much is it at a junkyard, and will it work if I replace it? I know the last one is a crap shoot but this does seem to be a sensitive system and I'm wondering if it's worth trying.

Or should I just pull the bulb and forget about it?

Mike
 
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epj3

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#2
stupidgeek said:
I have an 86 325es and the antilock light is on all the time. It used to go out until I had to jump the car and accidentally left the ignition on when hooking up the cables. STUPID! [?|] STUPID! [?|] STUPID! [?|]

Anyway, the light is on all the time and the antilock brakes don't work. I'd bet it's the control unit but I'm not very lucky at betting. Has anyone ever had to replace this unit, how much is it at a junkyard, and will it work if I replace it? I know the last one is a crap shoot but this does seem to be a sensitive system and I'm wondering if it's worth trying.

Or should I just pull the bulb and forget about it?

Mike
Click to expand...
Do they work? Next time it rains, get the car up to like 35mph and slam on the brakes.
 
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OreoGaborio

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I'm pretty sure i know EXACTLY what it is... when i was jump starting my car, my roommate thought i accidentally switched up the jumper cables w/ his truck and decided to flip the polarity on me before i could stop him... it blew out my abs at the relay.... but it IS a an easy fix...

here's what cha do:

first u gotta pull down the knee bolster & remove the ABS Relay. The relay clipped onto the top of the ABS "brain" which is the silver box that's about 1in x 4in x 6in... the relay is the little silver box clipped on top of it (kinda tough to get to) and is roughly 3/4in x 3/4in x 1in... just unclip it from the ABS "brain" and unplug it.

now... u can do one of two things...

1. replace the relay w/ a factory one (20-30 bucks from the dealer, maybe 10-15 for a used one)...or

2. u can repair the relay by picking up some 5 amp GLASS fuses for a couple bucks, opening up the relay, breaking open one of the fuses & souldering the wire from the fuse into the relay in place of the little wire that probably blew...

if you choose option number two, lemme know & i'll post detailed instructions on how to do that as soon as u let me know... [thumb]
 
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epj3

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OreoGaborio said:
I'm pretty sure i know EXACTLY what it is... when i was jump starting my car, my roommate thought i accidentally switched up the jumper cables w/ his truck and decided to flip the polarity on me before i could stop him... it blew out my abs at the relay.... but it IS a an easy fix...

here's what cha do:

first u gotta pull down the knee bolster & remove the ABS Relay. The relay clipped onto the top of the ABS "brain" which is the silver box that's about 1in x 4in x 6in... the relay is the little silver box clipped on top of it (kinda tough to get to) and is roughly 3/4in x 3/4in x 1in... just unclip it from the ABS "brain" and unplug it.

now... u can do one of two things...

1. replace the relay w/ a factory one (20-30 bucks from the dealer, maybe 10-15 for a used one)...or

2. u can repair the relay by picking up some 5 amp GLASS fuses for a couple bucks, opening up the relay, breaking open one of the fuses & souldering the wire from the fuse into the relay in place of the little wire that probably blew...

if you choose option number two, lemme know & i'll post detailed instructions on how to do that as soon as u let me know... [thumb]
Click to expand...
Damn man i Like you already, very helpful [thumb]
 
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stupidgeek

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OG,

Great idea. But since I know I never crossed up the cables (or did I - it was so long ago... naw, I'm way too smart to do that!) I'll pull the relay and check it in the hopes that it saved the computer during the power surge to the battery. It sparked pretty good.

Do you know if the schematic for the relay is on the label? That would let me check the operation without breaking it open. I've pulled apart a few relays in my time and have done a fair bit of soldering so the repair should be pretty straightforward. I just hope it sacrificed itself for the sake of the computer like it is supposed to.

I'll let you know how it turns out. Probably won't get to it until next week, though.

Mike

PS - I'm with epj3. You're all right.
 
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OreoGaborio

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#7
yeah i know u probably didn't swap the polarity, but i'm guessing since you had the same failure and it was jump starting related, it was probably the same thing...

as for the relay... i don't think the schematic is on the relay itself, but it does have some symbology on the bottom of it.... you'll see it

if i was a betting man, i'd still put my money on it being that tiny wire in the relay... u said you've pulled relays apart before, so i'm not too worried about cha, but just remember how everything was when u take it apart... there's a little paper card in there that prevents stuff from arching to the metal casing... just remember which side that goes on & you'll be all set...

if u do open it up, you'll see the wire i'm talkin about... it's a really thin piece, about 1/3 of an inch long at the base of the relay (the end that gets plugged in)

lemme know how it goes [thumb]

thanks for the kind words guys... and call me Pete [wave]
 
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OreoGaborio

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#11
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stupidgeek

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#12
Pete,

Pulled the relay apart and the fused link was open. Took a seven amp fuse (the relay said it was an eight amp relay - besides it was the only glass fuse I could find) and soldered the fuse part in. Put it back in the car and no more light on the dash.

Thanks for the great info.

Mike
 
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