The heated front windshield in my 2000 obw is not functioning. I would like to determine if the element is an open circuit which would mean that the windshield would have to replaced to repair the problem. The connections are obviously at the base of the windshield on the drivers side. Is there an easy to reach diagnostic spot that can be accessed without tearing the dash apart? The owners manual does not show this circuit on either fuse panel. Does it have an inline fuse or relay? If so, any idea where that inline fuse or relay is located? Is there any indication of the wire color and diameter of the leads to the heating element? I would have to guess that the wiring for this circuit is heavier than other wiring under the dash.

 

Steve

It should have a fuse. It may not be a separate fuse though. Does anything else not work?

 

You may want to try putting a voltage meter across both sides of each fuse to verify that they are good.

Only guessing her, but I would think that there is a relay involved as well. Switches just can't normally handle the amp draw of a heater circuit.

The heated front windshield in my 2000 obw is not functioning. I would like to determine if the element is an open circuit which would mean that the windshield would have to replaced to repair the problem. The connections are obviously at the base of the windshield on the drivers side. Is there an easy to reach diagnostic spot that can be accessed without tearing the dash apart? The owners manual does not show this circuit on either fuse panel. Does it have an inline fuse or relay? If so, any idea where that inline fuse or relay is located? Is there any indication of the wire color and diameter of the leads to the heating element? I would have to guess that the wiring for this circuit is heavier than other wiring under the dash.

 

Steve

 

How have you determined that it's not functioning to begin with?

are the wipers getting frozen to the windshield or is the button simply not lighting up?

Sorry for the lack of replies. I got caught up in other projects and was not getting on the web much this past week.

 

 

To answer the questions posed.

 

The owner's manual does not list the circuit as being fused. My guess is that it probably operates through a relay but not having a wiring diagram I just do not know.

 

I am fairly certain that the heated windshield is not functioning for 2 reasons. First the owners manual suggests not leaving the windshield heater on for more than 15 minutes as this may draw down the battery. From that statement in the owner's manual, I reasoned that such a draw should have a visable appearance in the brightness of the headlights. It does not. I see no change in the headlights brightness, no slowing of the engine as the load to the alternator should have jumped, and no drop of voltage as measured at the battery terminals. Second, the snow and ice of last weekend did not melt from the base of the windshield.

 

The button on the switch does go on and off when the switch is operated but fo the reasons I stated in the previous paragraph I do not believe that the heating element is operational.

 

What would be nice would be to locate a test point. Or, knowledge of the wire color and diameter that carries the current to the heating element, or the location of the relay (if so equipped). I have a volt / ohm meter and can test things if I had some idea where to test. I just hesitate to begin tearing apart my primary transportation for something that I find annoying but not required for the safe operation of the car.

 

Steve

i think it is like the rear defroster, that it is not built into the windshelid, but laminated on it.

 

Try #1 - see if you can read power directly off the grid on the glass

Try#2 put a voltmeter on the battery, with the car in the on position but not running, you should see a voltage drop on the battery (have somone else turn it on)

Try #3 pull the switch out and see if there is current going to the switch. Make sure the switch itself works.

Try# 4 look in the owners manual and see if they say what fuse works it. It may have its own fuse under the hood. Modern cars have 2 or three fuse boxes, not just one.

 

nipper

Sorry for the lack of replies. I got caught up in other projects and was not getting on the web much this past week.

 

 

To answer the questions posed.

 

The owner's manual does not list the circuit as being fused. My guess is that it probably operates through a relay but not having a wiring diagram I just do not know.

 

I am fairly certain that the heated windshield is not functioning for 2 reasons. First the owners manual suggests not leaving the windshield heater on for more than 15 minutes as this may draw down the battery. From that statement in the owner's manual, I reasoned that such a draw should have a visable appearance in the brightness of the headlights. It does not. I see no change in the headlights brightness, no slowing of the engine as the load to the alternator should have jumped, and no drop of voltage as measured at the battery terminals. Second, the snow and ice of last weekend did not melt from the base of the windshield.

 

The button on the switch does go on and off when the switch is operated but fo the reasons I stated in the previous paragraph I do not believe that the heating element is operational.

 

What would be nice would be to locate a test point. Or, knowledge of the wire color and diameter that carries the current to the heating element, or the location of the relay (if so equipped). I have a volt / ohm meter and can test things if I had some idea where to test. I just hesitate to begin tearing apart my primary transportation for something that I find annoying but not required for the safe operation of the car.

 

Steve

 

You're in southern Pennsylvania?...Have you tried turning it on when the bottom of the windshield is frosted up after parking outdoors overnight? Start the engine, leave the blower motor off, and turn the wiper defroster on just to see if the wiper park area begins to thaw.

If it's any consolation, the wiper defrost feature on our '98 Outback Limited doesn't dim the headlamps either. I'm fairly certain that the wiper defroster doesn't draw nearly the same amperage as the rear window defroster, because the heated grid area on the windshield is really quite small.

Doesn't the owner's manual say "don't leave the wiper defrost feature on....with the engine not running"? The wiper defroster will not draw down the battery if it's on while the engine is running (with a properly functioning alternator).

There are two things that you can probably count on. There is a relay that controls the voltage to the window, and there is a connector that you can disconnect to check voltages.

 

You'll probably have to find the wires coming from the window to be able to solve this probem. The window may read a couple hundred ohms, not sure, but aircraft windows work the same way, using a thermal film.

Nipper - you are correct the element is laminated to the windshield. It is so low that you cannot touch it from inside the car, so testing its operation in this fashion is not possible. Its one reason why the element itself normally cannot be damaged by use. The rear window grid is easily damaged. Even aggressive cleaning can leave one or more of the lines non functioning.

 

I like the idea of turning on the circuit with the car not running - I should have thought of that!

 

The frost on the windshield is another possibility for the next frozen windshield morning.

 

Checking the back of the switch is an idea that might work. I suspect that I will find power at that location because the indicator light does function. Any clues on how that switch is mounted? My guess is a couple of small screws on the back side of the dash hold the switch in place?

 

I also just saw on another thread that the service manuals may be downloaded from Subaru - but a $35 fee for 3 days is required just to find out what content is available. Anyone know what year 2000 info is actually available on the web site? Are the wiring diagrams available?

 

Steve

Put a new heated windshield in an OBW today.

The connection to the glass as someone else said is well below the dash line and cannot be accessed. Although, the hookup is under your drivers side interior A pillar trim. If you carefully pull on the trim starting at the top, there are 3 simple push in clips that will release. Once the A trim is off, near the base you will see a large white plug. This is where the wire comes from the windshield and hooks up. This is a good place to check to see what kind of current is actually getting to the windshield. (assuming both connections are still attached to the glass?)

Snce these things dont change much from car to car, i looked in my freinds 2005 Forester Owners manual. It said the heated windsheild fuse is #13 and located under the hood. The rear veiw mirror outside defrosters is also on the same fuse. May be worth looking there to start.

 

nipper

Today I was off and it was rather pleasent outside so I went back to testing the windshield. It appears that the heating element must be working as the voltage on the battery terminals was 12.7v with the key in the on position but not running. Turning on the heated windshield caused the voltage to drop to 11.8v. So something must be happening. It just seems to be very incompetent at melting the snow and ice off of the wipers.

 

I also rechecked the owners manual and did discover that the circuit is fused. In fact it shares a 20a fuse with the heated mirrors.

 

Steve