Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

Brake Warning Light

Thread Tools
 
Search this Thread
 
Old Dec 10, 2014 | 05:56 AM
  #16  
eakermeld's Avatar
eakermeld
Thread Starter
|
Cargo Master
Joined: Nov 2013
Posts: 2,168
Likes: 3
From: South Central,MO
The pedal is firm and the brakes function perfectly. It is definitely an electrical issue. If I only knew where that diode was I could probably fix it!
 
Reply
Old Dec 10, 2014 | 06:35 AM
  #17  
dixie460's Avatar
dixie460
Postmaster
Joined: Nov 2011
Posts: 3,533
Likes: 17
From: SW Florida
Originally Posted by eakermeld
If I only knew where that diode was I could probably fix it!
And a quick search says...

https://www.ford-trucks.com/forums/1...ock-light.html

Post #9 seems the most informative, post #6 just says the general location.
 
Reply
Old Dec 10, 2014 | 06:37 AM
  #18  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
Originally Posted by eakermeld
If I only knew where that diode was I could probably fix it!
For 1990 the Diode/Resistor Assembly is located in the main harness, near the Anti-Lock brake module.

For 1988 from the diagram post above for 1988 it shows it near S520. S520 is located near warning buzzer T/O.

T/O = a Take Out in a wiring harness (where wires split off a wiring harness).
 
Reply
Old Dec 10, 2014 | 06:44 AM
  #19  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
Originally Posted by dixie460
Post #9 seems the most informative, post #6 just says the general location.
Note that post #9 does not say what year the information is from and the Thread is about a 1992 truck that everything was different on than the 1991. The 1992 manual says "LH rear of engine compartment, taped in harness near C202 [6.7in from C202] (B9)". So it looks like it was from the 1992 manual.

So i would go by post #6 in that thread as it was from a 1989 manual.
 
Reply
Old Dec 10, 2014 | 07:08 AM
  #20  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
OK I found it in the 1989 F-series shop manual:


Both of these seem to say the same place:
For 1990 the Diode/Resistor Assembly is located in the main harness, near the Anti-Lock brake module.
Originally Posted by nitro94
In the 89 factory wiring manual it is listed as 44 inches from the parking brake switch. Thats all it says.
/
 
Reply
Old Dec 10, 2014 | 02:31 PM
  #21  
eakermeld's Avatar
eakermeld
Thread Starter
|
Cargo Master
Joined: Nov 2013
Posts: 2,168
Likes: 3
From: South Central,MO
Originally Posted by dixie460
And a quick search says...

https://www.ford-trucks.com/forums/1...ock-light.html

Post #9 seems the most informative, post #6 just says the general location.
Thank you Dixie!
Why is it when the person doing the search because they have a problem and desparetly need help can't find squat but everyone else can! I should have looked at more posts that included the antilock light but I didn't since mine only has the brake light on ant the rabs is working properly.
 
Reply
Old Dec 10, 2014 | 02:37 PM
  #22  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
Note that the Thread Dixie460 pointed to would be of no help to you as post #9 says it is under the hood and yours is inside the cab behind the dash.
 
Reply
Old Dec 10, 2014 | 02:40 PM
  #23  
eakermeld's Avatar
eakermeld
Thread Starter
|
Cargo Master
Joined: Nov 2013
Posts: 2,168
Likes: 3
From: South Central,MO
Originally Posted by subford
OK I found it in the 1989 F-series shop manual:


Both of these seem to say the same place:
For 1990 the Diode/Resistor Assembly is located in the main harness, near the Anti-Lock brake module.


/
Thank you Subford! That is great info to have. My truck has the rabs valve down on the frame but does not have a control module like a "real" rabs system. Is that wiring and diode still there or is it somewhere else?
Sorry to be such a pain to everybody. I know most people would just remove the bulb and forget it, but I like to try to keep my stuff right. I am a very capable mechanic and can do most everything, but electrical is not my strong point. Thanks again.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-1

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-2

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-3

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-4

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-5

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-6

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-7

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-8

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-9

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
Old Dec 10, 2014 | 02:54 PM
  #24  
eakermeld's Avatar
eakermeld
Thread Starter
|
Cargo Master
Joined: Nov 2013
Posts: 2,168
Likes: 3
From: South Central,MO
[QUOTE=eakermeld;14891934]Thank you Subford! That is great info to have. My truck has the rabs valve down on the frame but does not have a control module like a "real" rabs system. Is that wiring and diode still there or is it somewhere else?
Sorry to be such a pain to everybody. I know most people would just remove the bulb and forget it, but I like to try to keep my stuff right. I am a very capable mechanic and can do most everything, but electrical is not my strong point. Thanks again.[/QUOTE

I take the part about not having a module back, I see it now! But I have run out of time today to work on it. I will do some more testing and report back.
 
Reply
Old Dec 11, 2014 | 06:39 PM
  #25  
eakermeld's Avatar
eakermeld
Thread Starter
|
Cargo Master
Joined: Nov 2013
Posts: 2,168
Likes: 3
From: South Central,MO
Here is an update. Checked the diode in the harness and it's doing what it's supposed to. So the next step was to go back to whatever I did before I saw the warning light, which was the instrument cluster. So pulled it out of the dash and went over every connection on it looking for burnt of bad spots in the circuitry. Nothing. So I went and got my old cluster w/o tach and put it in. No light. Ok lets try the other one again. No light. WOO HOO! It's a miracle! Put the dash panels back and fired it up to move it out of the shop........there's that friggin' light again. WTH! So I guess there must be something bad in the printed circuit of the cluster that I cannot see that touches something when it's fastened down. Next time I get a chance to work on it, I'm going to take things apart one screw at a time and watch that light like a hawk and see what makes it go out.

If anybody has any insight on this, fire away!
 
Reply
Old Dec 12, 2014 | 07:53 AM
  #26  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
I may have missed something on this problem.
You are changing clusters, why?
Is the replacement cluster from the same year as your truck?
If it was the same year was it from a diesel and yours is a gas truck?
Dose one cluster have a tachometer in it and the other does not?
Did you get the replacement cluster from ebay, salvage yard or one of your other trucks?
 
Reply
Old Dec 12, 2014 | 08:17 PM
  #27  
eakermeld's Avatar
eakermeld
Thread Starter
|
Cargo Master
Joined: Nov 2013
Posts: 2,168
Likes: 3
From: South Central,MO
Originally Posted by subford
I may have missed something on this problem.
You are changing clusters, why?
Is the replacement cluster from the same year as your truck?
If it was the same year was it from a diesel and yours is a gas truck?
Dose one cluster have a tachometer in it and the other does not?
Did you get the replacement cluster from ebay, salvage yard or one of your other trucks?
I'm changing clusters because the little stud that holds the speedo needle broke off. Extremely rare failure, but pretty much normal for my luck.

Cluster came from a running 1988 truck out of a salvage yard. Everything I read said what I already knew, that anything 87 thru 91 is simply plug-n-play. Light wasn't on in that truck and wasn't on in mine for the first day.

From gas to gas.

Yes, the replacement has a tach, the old one did not. That was another reason I wanted it.

I know this is my fault because I did the oil pressure gauge mod but didn't change the sender the same day I changed the cluster and drove it for a day with the gauged pegged past H which burned something up. If you unhook the sender wire the light just barely glows. Hook it up and start the truck or ground it out and as soon as the gauge moves the light comes on bright. Now it's just a matter of figuring out what got cooked.

Thanks again for all the help you have given me so far.
 
Reply
Old Jan 2, 2015 | 08:33 PM
  #28  
eakermeld's Avatar
eakermeld
Thread Starter
|
Cargo Master
Joined: Nov 2013
Posts: 2,168
Likes: 3
From: South Central,MO
To update the thread. It was my fault. I burned up something in either the printed circuit or the indicator warning control assembly by doing the oil pressure gauge mod without changing the sender. So the fix was......

Installed Autometer sender part#2241. This sender has an OHM range from 70 to 10. Works perfect for the OEM gauge after the mod is done.

Got ANOTHER gauge assembly, did the oil pressure gauge mod, cleaned it up and installed it.

Now everything works perfectly. Thanks to everybody, especially Subford, for all your help.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ozzy_2_me
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
14
Jan 7, 2010 04:26 PM
turboguy
1987 - 1996 F150 & Larger F-Series Trucks
2
Jan 29, 2006 07:52 PM
2kf150
1997 - 2003 F150
6
Apr 2, 2005 12:14 PM
flagator
1967 - 1972 F-100 & Larger F-Series Trucks
5
Feb 19, 2005 08:56 AM
idealtrucks
1967 - 1972 F-100 & Larger F-Series Trucks
5
Nov 27, 2002 12:42 AM




All times are GMT -5. The time now is 04:59 PM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-1
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-2
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-3
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-4
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-5
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-6
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-7
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-8
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-9
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE