I went to the wreckers this Saturday to look for some heating pads to install on my existing seats, but I found a nice '96 with black leather, power, heated seats so I took the chance and bought them. I've modified the seat tracks so they fit in my '89 now, but I'm at a loss as to how I could / should wire them up.
My fuse box has empty slots that I could use if I insert some metal prongs for the fuse and wires to attach to (I'll just yank'em out of a spare fuse box I have lying around). But I'm no electrician and I've heard that with high-load circuts you can't simply run the power through the switch (specifically for the seat heater) cause it will over-load the switch in a hurry.
So I'm wondering if the correct way to wire these seats is to modify my fuse box with 2 additional circuts - one for the power movement of the seats, and one for the heated seats - and then put a relay on the heated seat circut?
Any help would be appreciated. Thx.

 

Yes, good plans.

Btw. Did u also get the sw panel?

What did u need to change? (For my eyes, 5gen seats = 3gen = stanza...)

I wouldnt bother with relay (originals dont have either), I'd not even add on fuses: I'd piggyback =add the load on some existing circuit and then use there little bigger fuse. (But dont believe me, do with your better plans...)

 

By 'sw panel' do you mean the switches? If so, then yes I got the switches too.
My old seat leather was too brittle to survive taking them off, installing heating elements, and then re-installing. Getting newer seats that were specifically designed to be heated from the factory seemed like an easier, safer way to go. I chose these seats because of the condition of the leather, heater and cost - seemed like the most economical way to fix my leather AND get heated seats. I'm not overly enthused that I will have power seats tho - as I actually prefer manual seat adjustment. I had to modify the seat track mounts extensively to get them to be a perfect drop-in, but in the end they're solid, fit really well and sit at the proper height.
If I were piggy-back a circut I'm afraid I'd be forever blowing fuses or worse yet that I would fry the wiring and possibly cause a fire due to the high-load on something like heated seats? At first I thought I would tie the heated seats into the rear defroster circuit, but then I thought about the load and the fact that much of the time I'd be using the heated seats, I'd also be running the rear defroster and the heated mirrors as well. That just seemed like waaaay too much for one circuit to handle safely?

 

Rear defrost sw is tied to ECU... activates A/C when pressed on. I would not like that with seat heater.

The seat heater is std 'on all nissans' here. But. I was lookin at my fuse panel - it does not list that, neither the US schematics... If u want, I could now go and check what circuit they are originally added on???

I am certain that as u got the original switches, they can handle the seat heater load.

 

Here is a thread of maxima-4dsc's install of 4th gen seats.. You have to be mechanically creative to get these seats in there.....

http://forums.maxima.org/showthread.php?t=356100

 

So I did go and mea-sure-x...

The stock seat heater(s) are fused to L13. No Relays. Both seats switches at Hi, draw only 4.45Amps. The 10A fuse is sufficient, switches have no problems...

 

Ya, you're right - I wouldn't want the AC to kick on whenever the seats were activated. So scratch that idea.
It'd be great if you could tell me how your heated seat system is wired! Thx.

I remember that post - I even asked for mount pics in it... ;-)
I didn't see any pics when I opened the link, do you have any? I also didn't notice if you ever answered when people asked if you got the power and heat to work? If you did, then perhaps you could tell me how you went about it and if you've experienced any blown fuses or whatnot?

 

Thanks so much Wiking! That should help A LOT!

I was worried about tying into that specific circuit since it's a pretty important one that runs so many things. Seems odd that the seats would only draw 4.5 amps tho? I wonder if the 4th gen seats draw that same amount?

 

Whatever happens to your seat heater & wirings, these resistors cannot harm the other circuits behind this fuse. Only fuse blows... Its like the 12V systems "danger" overall: one has to swallow the batt to get killed. And then most probably cause of death is the plastic casing... (What one should not do, is to drop wrench on batt poles, there follows nasty acid explosion.)

Heaters may differ in size, somewhat in amps. Do measure yours:

Attach +12V & gnd wires from batt directly to u heater. Install your Multimeter between (in series), first change multimeter probe to 10A setting, read. I bet reading is about same...

 

Anyone know if the 4th gen heated seats heat the cushion AND the seatback (like most modern cars) or if they just heat the cushion (like most cars did when seat heaters started to become more common)?

Bear in mind I haven't wired mine up yet, so I don't know...

 

I dunno - but have strong eu-pinion: yes they do as any nissan from 80's... Never heard one havin only on the cushion.

Btw. You can measure the the amps...

 

As I mentioned b4...., I'm not good with electronics... Electricity and I do not get along well...
So I know I could measure it myself (once it's hooked-up) but I don't have the slightest idea how to, or a strong enough desire to do so..
Hence why I ask the 'pros' such as yourself for advice and opinions.

 

The basic measurements are easy. First thing is to get handle of the fear that youll burn smtg. Rest assured, u will as u learn more. When u can burn customers equipment with straigh face and charge him, then you are a pro...

10$ multimeter DMM. Turn selector to 10A. Re-Position the red probe to adjacent 10ADC slot. For this current measurment, the current has to flow through, both seat resistor and your DMM. No Polarity requirements.

Get some wire: 'start' with wire from batt positive, attach to DMM one (whichever) probe, attach other DMM probe to seat one wire. Next connect seat second wire to batt negative. Now u have a closed circuit and current flows through it, gauge will give the reading - in the selected AMPS...

Simple measurement schema:

Batt+ -------◘DMM◘--------◘SeatR◘------Batt.neg.


Note: After measurement, return DMM probe to the slot it was before: VΩmA. This is because typically ppl do Voltage measurements. (From experience I can tell, u will lose all smoke from ultimeter if u try to measure battery voltage with probe in the 10ADC slot... I could not pump the billowin smoke back, but had to buy another 10$ multimeter.

 

WTF are you talking about???
the front defroster kicks on the A/C not the rear

 

Skimmin through the schema the other day, I tumbled on this connection. I'll check the nuances, but tomorrow. Bedtime here. Btw. No el front defroster in my max...

As always, I may be wrong. As always, I may be right. As always, reader is left responsible


Well here it is. See RH bottom -corner and the DEF -txt. As when if the schema is ok, The Rear win Defroster switch is workin parallel with A/C switch.

 

when you put on the front defroster (blows to the windshield) that activates the A/C
that shematic only shows defroster on the temp panel which is for the front

 

Yes, so it is. The RH button on the manual climate panel activates A/C. Thats the parallel DEF -sw in the schema.

Rear Defrost doesnt affect A/C any way. I was abs defr wrong.

Here one may ask nissan why-o-why this -not- tHat, as A/C is used to dehumidify cabin air in winter -and- cool in summer...

 

I thought that I was the only person with 4th gen heated seats on here

I tried to wire up the heaters on the seats but I ran into an issue. as you prob know shvelle, the stock connectons for the heated seats have 3 prongs on them. I assumed 1 for bottom 1 for back and 1 for neg. well I tried every single combination that I could think of and I could only get eather the bottom or the back to heat up. I could never get both the bottom and the back to heat up at the same time.

one thing I didnt try was hooking up 1 positive to one sorce and the other positive to another souce. I dont know if that would help or not.

I would really like to see you get this to work. then you can tell me how you hooked it up so that I can get my heated seats to work. winters comming and I hate cold leather in winter.

BTW if you want to see what my seats look like check out my cardomain page.

 

Seat bottom parts have two resistors R1 & R2, back has two resistors R3 & R4.

Bottom R1 is connected with Back R3 - that is one pin for Lo.
Bottom R2 is connected with Back R4 - that is second pin Hi.
All have common gnd - that is third pin.

Lo -switch position connects one heater element in bottom & back
Hi -switch position connects both heater elements in bottom & back

Then u have the thermostat(s). They disconnect at their nominal temp, connect few minutes later.

Maybe u have some wire broken? U have to open upholstery, follow wiring and determine the resistor heater elements and thermostats. Broken parts may be resoldered. Draw a picture on what u find... I may take a pic, measure on the workin seats.

 

I will check it out but I dont think its a wire broken, only because the same thing happens to both seats. I will take a look and see if I can find any wires broken.

 

I checked the Connector:

Place lock clip on top for correct view.
'first top row': one single connector pin A.
'second row': two pins side by side B & C.

Ign ON.

A gets +12V when switch is in Lo -position (C disconnected)
C gets +12V when switch is in Hi -position (A disconnected)
B is gnd

 

THAT IS AWESOME! THANKS wiking! when I get time I will wire them up that way and see if I can get both the bottom and top to work!

 

Ya, thanks for learn'in me Wiking! I'm sure the info you provided will come in very handy when I get to the point of wiring the seats. Appreciate your help!

 

That's really cool and skilled of you shvelle to do such a mod. But one thing you'll find is that during long trips, the third gen seats will be more comfortbale than the 4th gen seats. Were you able to get anymore stuff from the 1996 Maxima? I can sure use a set of ignition coils, and would certainly drive down there if it was worth it, seeing as I have never been to your city.

Oh, if you had black leather in your 1989 Maxima, be sure to switch the headrest from the 3rd gen to your 4th gen seats; the tilting headrest is a Godsend!

 

Update...

Both seat tracks have been modified to fit the existing mounts on the car and both seats are wire and installed and working fine. I chose to only modify the seat track mounts so I could instantly put a stock seat back in if I ever needed to. Modifying the tracks required that I cut/drill all 4 mounts off the 4th gen track and 3 off my stock seats. The 2 mounts closest to the outside of the car had to have a 1" spacer inserted between the mount and the seat track to get the seat to sit level. The rear, inside mount (near the back of the console) had to have a 4" (aprox) extension welded to to so it would reach the 4th gen seat track.
My choice to NOT modify the car mounting points resulted in 2 things...
1) the seats mildly rub against the center armrest (I have the thick one)
2) the seats sit aprox 1" higher at the back of the butt cushion than the stock seats did, which makes you feel as tho you're sitting higher.

Other things I noticed:
1) the driver seat is about 1/2" off-center from the steering-wheel (towards the console)
2) the power seats do not slide back as far as the stock (manual) seats did. NOTE: I checked a 4th gen seat movement with power seats and it too didn't go back that far - so that was not my error - it's just the seats.
3) The 4th gen seat cushion isn't as long as the 3rd gen, so it seems to provide less leg support. (this may be why Will said they wouldn't be as comfy on long trips)

WIRING...

To power the seats I first went to the wreckers and found a 3rd gen with factory power seats. I then cut-out the wiring harness that runs from side-to-side under the seats. After dismanteling that harness I discovered that the factory tapped-into the WHITE WIRE W/RED STRIPE for power, and any of the many black wires for ground. I wired it this way and it works fine. NOTE: wiring it this way ties directly into a 'BAT' circuit - meaning that the seats can be moved at any time, without having to turn the ignition to the ACC or ON position.

To power the heating elements I used my cigarette lighter circuit (since I no longer have a cigarette lighter...). I ran power and ground through that circuit to the switches and tied the seat harness ground to this ground as well. Using this circuit proved perfect because the wires run out from the bottom of the dash and under the console perfectly.
I then installed the switches in the console – one on each side to the e-brake lever.

DRIVER HEAT SWITCH:

WHITE = power
BLACK = ground
GREY w/BLACK = same to seat harness
GREY w/BLUE = same to seat harness

PASSENGER HEAT SWITCH:

WHITE = power
BLACK = ground
GREY = same to seat harness
GREY w/RED = same to seat harness

All in all I would say it was worth it. The seats don’t get as hot as I had hopped, but apparently that’s the seats. The seatback definitely gets warmer than the seat cushions. The wiring was the toughest part cause I over-thought it and because I wanted it to look factory (which it does now). Because of the welding and grinding and wiring required to do this – not to mention the time – I would say this is about a 9 on the ‘Trucks’ difficulty meter.

I’m still watching for shorts or fires or failures. If I get any I’ll update again.

 

so you got your seat heaters to work by using WHITE = power
BLACK = ground? what did you do with the 3rd wire? I guess you just left it alone. that is awesome that you got it all to work! you said that the bottom didnt get as hot as the back so I guess thats why I didnt think that I could get them both to work because one was just not as hot. congrads and props to you I would love to see pics when you get a chance.

 

My head is so retarded, that next morning there would be no click no nothin with described direct pwr sw settin. In my car, all has pwr consumption has to close before ign key drops into my pocket.

For me, this means a cutoff relay in seat heater supply as is in fuse L13 circuit.

 

The third wire coming off the seat harness is the ground (black) - and I tied that into the same ground as the heater switch (from the cigarette lighter circuit).

Seat Heater Switch = 4 wires
Seat Heater Harness = 3 wires
The power wire (white) only goes to the switch - not to the harness. Only ground and 'Hi' / 'Lo' wires run into the seat harness.

Oh...., and I forgot to mention that although the power seats run directly off the 'BAT' (trace white w/red wire to back of fuse box, note position, then look at diagram on fuse box door to see if the circuit is 'BAT', 'IGN', 'ACC'). The heated seats run off a 15 amp cigarette lighter circuit which only operates when the ignition is at least turned to the 'ACC' position - so there is no draw when the car is off.

 

Yess sir, youre right. Luckily at least my retarded head (=no ign, no ping) was proven.