So I was driving my girlfriends ford escort yesterday morning, and found it's one real redeeming quality (sure it's got better shocks, and more power, and a radio.....but all those things will be fixed on the chuxwagon in due time).....it's rear defroster can melt a thick layer of ice in a matter of a minute or 2....none of my subarus could do that to save their souls.....

 

anyone have an idea on how one could up the voltage, or amperage, or wattage, or whatever to make it heat up faster and hotter? I have a basic understanding of how it works, but not completely....

i have been looking forward to a thread like this for along time. I WANT TO KNOW!!! during winter this mod would REALLY help.

 

 

 

 

~Josh~

mine is always pretty fast - faster than my Mom's Aerostar or my Dad's Caravan - are your elements damaged? and which car? I have heard EA81 cars have poor rear defrosters - mine is an EA82 - I will confess I sometimes give it a run with the rear wiper, but only if some of the fog is outside

Check grounding? - dunno

 

I guess if you wanted to you could glue fine nichrome wire (heater wire) to your rear window in place of the defroster, and wire that in ....... be careful tho

well, if we had sigs you could tell what my car is [/editorial comment]

 

'88 gl wagon, ea82

 

I've got one element broken, but other than that, they all work. mediocre on dew, not at all on frost/ice, I've got to scrape it off by hand (the escort will defrost the rear in the time it takes to scrape the front)

sorry - I hadn't noticed that they had removed our signatures (I had my car on mine) - that annnoys me, cuz I am going to get tired of writing it

 

1985 Subaru GL Wagon

 

I guess I never have a problem with it because I always de-ice the car by hand anyway - prevents anything else from getting on the road when I drive off - my main concern is that it prevents fog-ups and dew (wiper can also do dew) - I sometimes put de-icer in my rear wiper washer resivoir too - that makes a BIG difference

there was one repair to the defrost system, but it was ~14 years ago, and I was too young to know (or care) about the details - I think the switch was replaced - as far as I have seen though, the system is factory spec

 

I wonder if the escort is the exception? the aerostar takes 20-30 minutes to properly de-ice by itself (on a good day, maybe less), and I don't want to know how long the caravan tales - mine takes 10-15 minutes if I let it de-ice by itself, but i rarely do that - defogging is almost instantaneous (what I care about)

 

just out of curiosity - does your girlfriend use RainX or some other window treatment? that affects it too - I don't like it because it does weird stuff to your windows, but it does help with de-icing - quickie lube places often apply it when you have your oil changed

You can think of the rear defroster as a light bulb... its just a wire with reisitance running through the glass... First thing I'd do is "relay-it-up". pull the existing wires, make that the signal for the relay and run something heavier to the battery... You have to be dedicated to do all that, but it will ensure that you are getting full power to the defroster... or you could just check the voltage and amp draw.

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~Only yellow lowered FWD 5-speed XT-6 Ever

~87 Lifted "outback" wagon

~84 BRAT For sale, Rick not included

 

Rick plus RWD = Sweet Jumps

Whatever one is harder to blow up.

To expand on kbd's post,

about all you can do is make sure you have a good power and ground line to the grid. Do this by checking the voltages while the defroster is on/off. If the positive side is dropping below the battery voltage, or the ground side is going positive a bit, there are some bad connections somewhere that need to be cleaned/bypassed. Same for the ground side.

 

Since the resistance on the grid is constant, the only way to make it 'work better' it is to get more voltage across it, either by cleaning connections or running bigger wires from the battery.

 

I checked the current draw on one of my EA82s once, and it was around 5 Amps (so be careful while you're working on it).

 

Out of curiosity, how many lines/how big is the window on the escort?

I'm not sure on the exact size of the window, but I think it's at least as big as the one on my subie...

 

I understand the basic concept behind it, it's a heating element, more power = more heat, basically. but I wasn't sure about exactly how.

 

Well, the next time the Chuxwagon runs, I will have rewired dang near the entire thing anyway, so I suppose I'll just make sure this get's looked at anyway

I usually find just removing and cleaning the two contact wires where they slip over the prongs on the windshield helps -- sometimes I've used just a pencil eraser, sometimes I've used electronic parts contact cleaner (the pressure can and brush thing from Radio Shack). Don't use sandpaper, you want a smooth but clean surface.

 

Corrosion seems to happen fast in that area because, uh, it's often damp.

 

I have several wires not working too; I'm about to try one of those electrical circuit writer pens after I go over the wires with a magnifying glass to find where the connection's broken. The brown color is just glue, I think, it's continuous, but there's a slightly darker line in there that must be the resistance wire.

I have several wires not working too; I'm about to try one of those electrical circuit writer pens after I go over the wires with a magnifying glass to find where the connection's broken. The brown color is just glue, I think, it's continuous, but there's a slightly darker line in there that must be the resistance wire.

 

I also had to repair a couple lines on my loyale.

 

Easiest way to do it...

connect multimeter ground to the ground side of the grid (doesn't really matter though)

put a piece of aluminum foil on the other multimeter lead.

Run the aluminum down each known bad trace, watching the voltage. Soon as it 'jumps' you've found the break.

 

'jumps' - as you run down the bad trace, it will stay at one voltage. After you cross the break, it will jump to a different voltage level.

If you run down a good trace, the voltage should linearly increase/decrease depending on which way you're going.

use a test light, going from one side to the other should go from full bright to very dim