legacycentral bbs

Installed some 98 outback (limited) wagon front seats yesterday. Direct bolt in minus the seatbelt latch. Now I just need to hook up the heaters but have a few questions.

First: What model early legacy's came with heated seats and did they have a two position switch like the 98's? I would love to put in a stock looking switch installation if possible.

Second: What kind of amperage is flowing to the seats on high? I'm going to wire in relays regardless of what kind of switch I end up with so just need to see what rating I need.

Since you're not getting any response and I can't answer, check out:
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TD

I'm going to sit down with the service manual I think and do some figuring on wire sizing and what not. If I can stay motivated I'll try and do a write up on the setup. My goal is one main wire from the battery to a set of relays, then on to the seats. Now I just need to find some switches...

I'll be very interested (and grateful) to see your progress on this.

I have heaters in my '03 WRX seats that would be lovely if operable this winter....

suba wrote:I'm going to sit down with the service manual I think and do some figuring on wire sizing and what not. If I can stay motivated I'll try and do a write up on the setup. My goal is one main wire from the battery to a set of relays, then on to the seats. Now I just need to find some switches...

It should be pretty simple to wire in the seats, my e30 was pre wired for it, and all it was was a couple wires from the engine bay, and a couple from the seat. I haven't heard of 90-94 legacys with heated seats, but I'll go check if it's in the brochure.

Wave if you ever see me I'm going to school in Pullman, stock looking Slate grey metallic SS with tinted windows, I'm pretty sure I'm the only turbo over there...

Sweet, ya I've definitely seen your car, mine is the light blue N/A with the giant hellas on the front.

I just today saw a first gen post face lift legacy with heated seats. I thought that was odd. Should have taken a closer look. I do remember two switches in the center console. They were a rocker type switch with a dip in the center. Where the second gen switches are much flatter and larger. I cannot remember if it was a three position switch. When I stop by the dealership this week I will try to remember to take a look at it.

I was looking at it because it was in really nice shape, sun roof, heated seats, and the same color as my 93

Well, wtdash is sending me some switches from an outback so I can just mount those in the center console, should look pretty decent. I do have an electrical question for you gurus out there though. Looking through the diagrams for the heated seats:

http://www.main.experiencetherave.com/s ... iagram.pdf

It looks like there is a single power relay to the heater switches, from there it runs to the heater elements. It seems to me this means that ALL the current for the heaters runs through the switches and not relays, or am I off on that? Also, anyone know what the max current draw with both heaters on high might be? I see a 20 amp fuse in the diagram, so conservatively I can use a 30 amp relay and fuse setup. Thoughts?

I need to figure this out as well....I have the 98 outback seats with switches and can't get it to work.

Looks pretty basic. The switch has a low and high output and both seats on hi would only be 20 amps. Not too bad. If you're using the factory switches then you will be fine. you could also use two micro SPDT switches and use 3 relays instead. I have no easy way to draw this up however.

It will work with the factory wiring diagram. At most with both seats on high should be drawing 20A. Otherwise the fuse would blow on stock cars. Personally I would put heaver wiring in than stock. Probably 12-10 Ga. Just to make it a little more efficient and then measure voltage drop and compare voltage drop with and without extra relays and with and without the factory switches. I will be installing heated seats into my 99 legacy. But I have so much more work to do that I know I wont get around to design & implement this for some time.

Sounds good, my plan will be as follows I think:

-10 gauge wiring from battery to relay (fused)
-Ground from main connection to relay (undecided where yet)
-Relay connected to ignition source for activation (cigarette lighter circuit most likely)
-30 amp relay with two outputs to factory switches
-switches wired to seat heater harnesses

When I get around to doing this (probably next week I hope?) I shall make a little writeup, with a wiring diagram perhaps.

Testing my seats did result in finding one bad circuit on the drivers seat. The ground and one heater element appear to have a good connection, so hopefully I can repair the other connection. Otherwise I suppose I'll just have low heat, better than none I suppose.

jesus christ guys, 10 awg wire for 20 amps? follow the chart people...



16 to 14 is plenty good.

Ya...10 may be a bit excessive for two heated seats....BUT I do have a reason

I kinda forgot to mention, I'm considering at some point in the future adding an inverter in the center console with a plug out the back so I thought I'd leave myself some extra capacity for future expansion. I may or may not do that, I need to take a look inside the center console to look at my mounting options. You are however totally correct, 10 gauge is a little unnecessary

I prefer larger wires, esp when I have lots of 10 floating around.

More so for headlight wiring were a small voltage drop can mean a significant drop in lumen output (for a flashaholic). The larger the gauge the lower the voltage drop and higher performance.

For 12V

In 7 feet, using 10 AWG you get a voltage drop of about 0.288V

In 7 feet, using 16 AWG you get a voltage drop of about 1.166

Voltage drops are measured under full load.... btw

When it comes to incandescent light bulbs a 1V drop is a significant reduction in lumen. Heated seats probably not so much.

I like to get as much power as I can to what I am running. And using a larger wire really has no downside once installed.

And the ratings given for AWG are in ideal situations being "single wire with open air cooling"

The wires you will be using will be contained in bundles with other wires, stuffed under carpets.

Current capacity drops when a wire is heated.
De-regulated capacity for a wire in a bundle for power transmission (can vary on who you ask, but this is fairly close)
14 gauge - 17 amps
12 gauge - 23 amps
10 gauge - 33 amps
Add engine bay heat etc.....

So honestly in real world conditions I would use 12 gauge at MINIMUM. Its my car and I like to keep things cool.

If you dissagree, meh its your wiring but for the extra $5 in wires. Ill go 10 AWG.

Not much more I could say if you are not convinced.

Wiring installed, I think its working, kinda hard to tell when it's 85 outside. Later this week I'll post some install pictures/diagrams

soooo.... last night when the temperature dropped I thought I'd jump in the car and see if the seats got hot. Turned the switches to hot, seems to be working. Turned the switches to low....dash lights. Now, I very carefully wired the switches up using the 99 fsm so either the switches are different on a 98 (unlikely), the wiring is different on a 98 (unlikely), or I have the same wire crossed on both switches (also unlikely). I'm going to pull them out sometime soon here and double check to make sure I didn't look a the diagram backwards or something.

Once again it comes down to "check the obvious first". Checked the switches, they're fine (though with three burnt bulbs). Started checking my wiring and realized that I was looking at the diagram with the plug side , not the switch side so I connected the wires to the switch inverted. So remember kids, read first, plug second. quick swap around with the connectors and viola! Heat!

I was gonna say, if I turn on the seat in the g35 on the hottest day my ass still feels like its on fire lol.

I would love to see your wiring diagram. It would be nice to get these working before it gets cold.

Also, how did you test the heating elements in the seats? I need to see if my seats are even in a condition to work.

Hmm...sorry the bulbs were burnt out. Was not aware.

FWIW, I've heard the reason the elements burn out is because people leave them on all the time. I don't think the switches have a built-in timer.

TD

No worries, I don't really care about the bulbs, switches work just fine.

I started going through the pictures and will be putting together a wiring diagram tonight hopefully.

^^^^ yes please! & thank you.

Sorry for the delay, but I ended up having to leave town until next week so I will post pictures and diagrams as soon as I get back!

Okay, first the disclaimer: Sorry about the fuzzy pictures, didn't realize until after I got everything back together that there was a problem with my camera

lens. Also I realize the wiring diagram is a bit crude so if you need any clarification feel free to ask me.

So here is what I started with: 98 outback seats, both plugs on the seat side and no plug for the switches. Finding connectors that will fit on the thin

connector of the plugs is possible, but a pain so I would recommend getting the switch plug as well if you can. These went in to a 90 Legacy L model, though

wiring is the same for any car that doesn't already have a seat heater wiring harness.

What you need:

*~10 ft of wire from battery
*Inline fuse for
*wire for grounds (anywhere from 2 feet and up depending on where you choose to ground it)
*wire for seat to switch harnesses (recommend 20 gauge, larger is unnecessary and just makes the bundle big)
*Relay (minimum of 20 amp, dual 87 terminals is easiest, standard trailer wiring relays work great)
*female spade connectors if you don't have harnesses for switch and seat
*Post connectors for Battery connection and grounds
*Splice connectors if needed
*Zip ties, lots of zip ties

What I used:
*10 gauge wire from battery (little excessive, but I plan on installing future rear power outlets so I wanted extra future capacity)
*14 gauge wire for grounds (I like black grounding wire, and thats what I had laying around)
*16 and 18 guage harness wires (used what I had)
*40 amp relay (just happened to be the one they had in stock with two 87 terminals)


Step 1

Run the power wire from the battery with an inline fuse (fuse should be close to the battery)






On the first gen legacy's there is a little rubber cover on the passenger side. Poking a little hole in the rubber lets you slide the wire through just

behind the glovebox and you can route it under the carpet and up the center console.

Step 2

Connect/install relay. I mounted mine right next to the handbrake and grounded the ground terminal to the mounting screw.



The red wire comes from the battery, green is the relay activation source. I used the power wire for the cigarette lighter for this, but any source that

powers on with the key will work. The idea here is to shut off power to the seats whenever the car is off to prevent battery drain. The brown wire in the

picture is the ground.

Step 3

Build/connect seat harnesses. I forgot to take a picture of the harness before I installed it but I'm sure you have an idea of what it should look like.

Luckily this part is only three wires so shouldn't be too tough to route, I went under the carpet via a hole I carefully cut with a razor. (having the seats

out would have made this WAY easier)

Step 4

Connect the switches. This is where the wiring gets a bit messy, make sure you have everything clearly labeled to avoid hooking things up wrong, or backwords

in my case. One thing to remember is that the seats do not ground via the switches directly so the ground wire in that harness does not need to be bundled

with the other two wires. If you plan ahead this means you can connect those grounds first, out of the way, and have two less wires running around in your

switch area. My finished harness looks like so:



with a ready to connect bundle as such:



Step 5

Close switch panel and admire your handiwork.



Of course, if you have a little more motivation you can always make your switch installation a little prettier, I got a little lazy so they stick out a bit.

Step 6

Flip the switch to high and sit back and wait for that nice warm butt.
Step 7

Troubleshoot why your butt isn't warm. If you get to this point start with the easiest first. Check to see if you remembered to put a fuse in the fuse holder

(because you were smart and DIDN't put one in the first place I hope). Next check your grounding wires. Then check the Switches for proper operation (FSM

link below). Check the harness and seats for proper connections (FSM again). Check the wiring diagrams again just to double check that you read it right. Log

on to the bbs.

Wiring diagram and Links



FSM Service Procedure
http://www.main.experiencetherave.com/s ... cedure.pdf

Factory Wiring Diagrams
http://www.main.experiencetherave.com/s ... iagram.pdf

Final notes

First, keep things neat, loose wires are lazy and are the leading cause of gremlins. Second, use shrinktube and solder whenever possible. Twist connections and electrical tape are not the best and only save time the first time you install it. If anyone has any questions feel free to ask.