Headlight washers
#1
04-27-2013, 10:02 PM
Headlight washers
I have a 96 SE7 and the headlamp jets don't want to work for me. I stood by the reservoir while my son activated the washers with the headlights on. The middle pump on the tank comes on after about 1 sec delay, runs for 1 sec and then cuts out. Everything else on the truck works great with the exception of cruise control. Is it possible the middle pump is dead or is there a relay or something else I can check? If the pump is dead can you replace just the pump or are theses built into the washer reservoir?
#4
04-28-2013, 08:10 AM
Super Moderator
zigzag3141 - when the pump ran, did it squirt? If not, there is a "T" valve on the fluid line between the washers where the pump connects, it is a "anti-drain back" valve. Could be stopped up. Pump is also replacable. See attached pages from your copy of the RAVE workshop manual. You should be able to remove hose from pump and blow air thru it, the T valve, and out the washer stubs. You can also run the pump without hose attached to see if it squirts, maybe even poke around the grille (oops - front bumper) and find the T valve.
Last edited by Savannah Buzz; 04-28-2013 at 08:30 AM.
#6
04-28-2013, 12:11 PM
#7
05-07-2013, 09:28 PM
So I finally got a different tank, plugged it in, and it does the same thing. With the headlights on, when you activate the windscreen washer, the center pump comes on after a brief delay and then quickly cuts out. Are the headlight washers designed this way i.e. to pulse once briefly? My headlamp washer still do not work however if all you get is a pulse I can imagine it will take a long time to prime the hose. Maybe it will start working someday...
If someone reads this who has a D1 with working headlamp washer can you please let me know how yours work?
If someone reads this who has a D1 with working headlamp washer can you please let me know how yours work?
#8
05-07-2013, 10:11 PM
Super Moderator
On a D1:
The headlamp washers operate automatically
whenever the windscreen washers are operated,
provided the headlamps are illuminated and switched
to dipped beam. For continuous washing, hold the
windscreen washer control in the washposition E.
On a D2 -
Operating the front washer switch with the headlamps switched on energises the IDM, supplying a voltage to the
headlamp powerwash relay, which operates the headlamp powerwash pump and increments a counter within the
BCU. This counter prevents the headlamp powerwash pump from operating every time the front washer switch is
activated. Headlamp powerwash is only operational every third front wash cycle, providing the headlamps are on.
The counter resets when the ignition switch is turned off.
When the BCU permits headlamp power wash operation, the pump motor operates only for 0.5 second.
The headlamp washers operate automatically
whenever the windscreen washers are operated,
provided the headlamps are illuminated and switched
to dipped beam. For continuous washing, hold the
windscreen washer control in the washposition E.
On a D2 -
Operating the front washer switch with the headlamps switched on energises the IDM, supplying a voltage to the
headlamp powerwash relay, which operates the headlamp powerwash pump and increments a counter within the
BCU. This counter prevents the headlamp powerwash pump from operating every time the front washer switch is
activated. Headlamp powerwash is only operational every third front wash cycle, providing the headlamps are on.
The counter resets when the ignition switch is turned off.
When the BCU permits headlamp power wash operation, the pump motor operates only for 0.5 second.
#9
05-08-2013, 06:49 AM
Super Moderator
and...
Headlamp power wash energised for half a second
That blurb from the electrical guide, for the multifunction unit. This is a timer module in a white box on the back of the main fuse panel under dash. It controls a variety of timing duties, like dome lights dimming, rear wiper, etc.
The box can fail and take one or more functions with it. I think it "grew" into the BCU of the D2.
Here is test for the module:
7. The MFU will then exit the diagnostic mode.
Headlamp power wash energised for half a second
That blurb from the electrical guide, for the multifunction unit. This is a timer module in a white box on the back of the main fuse panel under dash. It controls a variety of timing duties, like dome lights dimming, rear wiper, etc.
The box can fail and take one or more functions with it. I think it "grew" into the BCU of the D2.
Here is test for the module:
Diagnostic Procedure
1. Close all doors and the tailgate.
NOTE: If the oil pressure switch goes open circuit
(engine is started) during the following procedure,
the MFU will exit the diagnostic mode immediately.
(engine is started) during the following procedure,
the MFU will exit the diagnostic mode immediately.
2. Press and hold the heated rear screen switch
and switch on the ignition.
3. Release the heated rear screen switch within 2
seconds and the MFU will beep to indicate that it’s in
diagnostic mode 1.
4. Press the heated rear screen switch; the MFU
will beep twice. In turn, operate each of the following
switches, heated front screen, rear fog guard lamps,
side lights, headlights, front wiper and rear wiper.
The MFU will beep twice each time a switch is operated.
5. Pressing the heated rear screen again will cause
the MFU to enter diagnostic mode 2.
6. The MFU will provide outputs to the following in
order given below:
and switch on the ignition.
3. Release the heated rear screen switch within 2
seconds and the MFU will beep to indicate that it’s in
diagnostic mode 1.
4. Press the heated rear screen switch; the MFU
will beep twice. In turn, operate each of the following
switches, heated front screen, rear fog guard lamps,
side lights, headlights, front wiper and rear wiper.
The MFU will beep twice each time a switch is operated.
5. Pressing the heated rear screen again will cause
the MFU to enter diagnostic mode 2.
6. The MFU will provide outputs to the following in
order given below:
Heated rear screen relay energised for 2 seconds
Heated front screen energised for 2 seconds
Courtesy lights energised for 2 seconds
Dim dip relay energised for 2 seconds
Rear fog guard lamp energised for 2 seconds
Headlamp power wash energised for half a second
Front wiper energised for half a second
Rear wipe/wash energised for half a second
7. The MFU will then exit the diagnostic mode.
#10
05-13-2013, 03:23 PM
Super Moderator
changed my pump still the 2 second burst
ran the test procedure for mfu and second time around they started working
now I hit the sprayer and they spray ( with low beam on) for 2 seconds think that's all they are supposed to do on each pull, right? looks like high pressure coming out one less thing to fix yeaaah
ran the test procedure for mfu and second time around they started working
now I hit the sprayer and they spray ( with low beam on) for 2 seconds think that's all they are supposed to do on each pull, right? looks like high pressure coming out one less thing to fix yeaaah
