91HerndonEx
New Member
- Joined
- April 25, 2009
- Messages
- 7
- Reaction score
- 0
- City, State
- Herndon, Va
- Year, Model & Trim Level
- 91 XLT
My 91 Explorer does not light the Parking (P) or brake warning (!)dash combination indicator light for any of these 3 conditions: parking brake lever depressed, low brake fluid level, or during the ignition start cycle which works thru ignition switch to check the light bulbs. I have read the posts I could locate here and generally on web, and my Haynes manual, and tried the following:
1) checked fuse 11 ( 15A) on both the inside and engine bay fuse panels, they both appear unbroken.
2) swapped new bulb into Parking/Warning Brake instrument console position and swapped bulbs between seat belt indicator and parking/ warning brake location. new and original bulb and socket appear OK as they both work OK in the seat belt indicator socket.
3) used an old shop vac to remove brake fluid from res until the float drops down. No brake warning light on, but the Rear ABS indicator lights (as it normally does momentarily during ignition cycle) and with low fluid stays on after start, which seems to indicate float and switch and RABS control module generally working OK.
4) disconnected and cleaned with CRC and toothbrush contacts for what I think is the DRL bypass wiring harness plug at driver's side radiator upper support (just under the "shelf" under the hood and to right of radiator when opening the hood ans standing in front of vehicle).
5) used multimeter to check the flex PCB wire trace between the individual pin for dash connector to the Brake P ! indicator light position positive side. That trace appears unbroken (on GND side of same Parking/Warning Brake bulb socket trace with ohmmeter to check all pins on same connector... could not really find a GND side connection to any particular pin on that connector), although other indicator lights like seat belt do show some connectivity on the GND side of their sockets to various pins on the same side (ground oriented ?) of the same cluster connector
6) Tried removing and bypass (back to normal) an aftermarket trailer light harness, even though this should have no direct relationship.
7) Tried CRC cleaner and then disconnect of the parking brake switch itself, .
Does anyone have a link or source for schematic that is better than the Haynes manual with its DRL block diagram stuff that confuses the issue?
Am I looking at Correct fuse location ?
I plan to try to test both fuse location 11's to see if they are actually getting voltage on supply side, etc. ?
There is also somewhere in the wiring harness a diode resistor assembly that sums the warning conditions, but could not find details, is it taped into or attached to wiring harness close to the instrument cluster like aerostar van ?
When all 3 modes fail, I would suspect the fuse (supply) , the bulb or instrument cluster PCB, (destination) or this Diode/Resistor assy, but not finding much detailed info to clearly tell If I am checking the right locations or conditions. Is it possible that a single part failure on one "leg" like parking brake switch or ignition switch cycle would keep all 3 faults/bulb test cycle inputs from being shown; ie, as a non-failure rather than a lit indicator?
It's a hobby project / backup vehicle, and even though the parking brake, and normal brakes work OK, the indicator not lighting just for parking brake is enough to fail state safety inspection, so I would like to try to get the reject sticker off. The inspector thought he saw the Brake indicator light on start-up cycle, but I think it was actually the Rear ABS indicator, which does a similar bulb check and lights up reliably (and stays on if low fluid).
I could get a recycled instrument cluster (unknown) for maybe $ 75, but would like to identify the correct things to check before throwing in more variables.
The inspector was laughing; is it worth it - to try to keep up an older vehicle ?, but it has some sentimental value, and still looks, drives fine and only 150K, which for a pushrod V6 should be only halfway into its life, so far - for its generation of electrical wiring harnesses, it is not bad, everything mostly works; door locks, windows, seats, AC, cruise, etc, but after rebuilding the transfer case servo motor twice, the only real mod was to make a copper tube/spring steel lever to engage 2H/4H change direct to xfer case thru floorboard instead of dash push-button.After working on my Honda all day in cramped conditions similar to the Ex's engine bay, I am in a solid state of denial - which will only end when the parting out process begins, or the thing falls on me in the garage.
1) checked fuse 11 ( 15A) on both the inside and engine bay fuse panels, they both appear unbroken.
2) swapped new bulb into Parking/Warning Brake instrument console position and swapped bulbs between seat belt indicator and parking/ warning brake location. new and original bulb and socket appear OK as they both work OK in the seat belt indicator socket.
3) used an old shop vac to remove brake fluid from res until the float drops down. No brake warning light on, but the Rear ABS indicator lights (as it normally does momentarily during ignition cycle) and with low fluid stays on after start, which seems to indicate float and switch and RABS control module generally working OK.
4) disconnected and cleaned with CRC and toothbrush contacts for what I think is the DRL bypass wiring harness plug at driver's side radiator upper support (just under the "shelf" under the hood and to right of radiator when opening the hood ans standing in front of vehicle).
5) used multimeter to check the flex PCB wire trace between the individual pin for dash connector to the Brake P ! indicator light position positive side. That trace appears unbroken (on GND side of same Parking/Warning Brake bulb socket trace with ohmmeter to check all pins on same connector... could not really find a GND side connection to any particular pin on that connector), although other indicator lights like seat belt do show some connectivity on the GND side of their sockets to various pins on the same side (ground oriented ?) of the same cluster connector
6) Tried removing and bypass (back to normal) an aftermarket trailer light harness, even though this should have no direct relationship.
7) Tried CRC cleaner and then disconnect of the parking brake switch itself, .
Does anyone have a link or source for schematic that is better than the Haynes manual with its DRL block diagram stuff that confuses the issue?
Am I looking at Correct fuse location ?
I plan to try to test both fuse location 11's to see if they are actually getting voltage on supply side, etc. ?
There is also somewhere in the wiring harness a diode resistor assembly that sums the warning conditions, but could not find details, is it taped into or attached to wiring harness close to the instrument cluster like aerostar van ?
When all 3 modes fail, I would suspect the fuse (supply) , the bulb or instrument cluster PCB, (destination) or this Diode/Resistor assy, but not finding much detailed info to clearly tell If I am checking the right locations or conditions. Is it possible that a single part failure on one "leg" like parking brake switch or ignition switch cycle would keep all 3 faults/bulb test cycle inputs from being shown; ie, as a non-failure rather than a lit indicator?
It's a hobby project / backup vehicle, and even though the parking brake, and normal brakes work OK, the indicator not lighting just for parking brake is enough to fail state safety inspection, so I would like to try to get the reject sticker off. The inspector thought he saw the Brake indicator light on start-up cycle, but I think it was actually the Rear ABS indicator, which does a similar bulb check and lights up reliably (and stays on if low fluid).
I could get a recycled instrument cluster (unknown) for maybe $ 75, but would like to identify the correct things to check before throwing in more variables.
The inspector was laughing; is it worth it - to try to keep up an older vehicle ?, but it has some sentimental value, and still looks, drives fine and only 150K, which for a pushrod V6 should be only halfway into its life, so far - for its generation of electrical wiring harnesses, it is not bad, everything mostly works; door locks, windows, seats, AC, cruise, etc, but after rebuilding the transfer case servo motor twice, the only real mod was to make a copper tube/spring steel lever to engage 2H/4H change direct to xfer case thru floorboard instead of dash push-button.After working on my Honda all day in cramped conditions similar to the Ex's engine bay, I am in a solid state of denial - which will only end when the parting out process begins, or the thing falls on me in the garage.
