electric seats

[barkster1971]

My 940 was already pre-wired for elecrtic seats on the driver's side but not on the passenger side. I am almost there wiring them up but there are three wires involved (from a V90). Red, black and orange. I presume red is +'ve , black -'ve/ground but what is the orange one for? I guess there's a relay involved somewhere as I get a nice click when the black and red and wired and got the seat to recline briefly. Has anyone successfully done the transplant. Can the relays be removed and the seat still work?
Cheers, Carl.

[barkster1971]

Well after a bit of google it apppears the orange wire is switched 12v.
Black - Ground
Red/Black - Permanent positive via 30A Circuit breaker
Orange - Positive via 15A fuse
White - To diagnostic unit pin 6 (or any available space depending on your car)
May twist them (orange and red) together and see what happens!

[FIREBOLT]

I guess these three wires are from the electric seat itself?I thought the seats had a control module underneath them with any relays required. The wires to them are just to supply power.

Originally Posted by barkster1971

Well after a bit of google it apppears the orange wire is switched 12v.
Black - Ground!

This obviously goes to earth, have you got it bolted down to a good earth?

Red/Black - Permanent positive via 30A Circuit breaker

I guess this is power for the seat motor(s) itself as it requires a 30A supply. Is this wire bigger than the others?

Orange - Positive via 15A fuse

This is power for the switches on the seat, small current to operate the relays in the seat module.

White - To diagnostic unit pin 6 (or any available space depending on your car)
May twist them (orange and red) together and see what happens!

You said these are switch & permanent live, they are not meant to be joined together. The red/black is the main power cable for the seat motor. The orange is power to a switch(es), which should operate a relay to power the seat motors.

[barkster1971]

The bug bear is the relays. The leather seats have a big green relay underneath. If you put the V90 heated seat connectors together they will not heat up (in a 940) although the 940 has heated sets. Once the relay was removed the heated seat worked. I think this is beacuse the relays need an exact current to work correctly.
In the 700/900 FAQ it gives instructions on how to wire up the electric seats which says once the red and black wires are connected it will work. It will not. I think I'll have to connect both the red and orange wires to the correct fuses in the fuse block to get this to work. i.e red to a 30A fuse, orange to a 15A fuse. I'll have to see what current I'm getting then I think I'll be in business.
The easiest option may be to T into the wires on the drivers side. I'll see tomorrow. The black ground wire can just attach to the bolt.
I guess the red constant 12V is to retain the 3 memory functions?
cheers, Carl.

[FIREBOLT]

Originally Posted by barkster1971

The bug bear is the relays. The leather seats have a big green relay underneath. If you put the V90 heated seat connectors together they will not heat up (in a 940) although the 940 has heated sets. Once the relay was removed the heated seat worked. I think this is beacuse the relays need an exact current to work correctly.

Relays are quite simple, they are just an electric switch which uses a small current to operate a soleniod to switch a large current on. As you don't really want a 30amp supply to a small switch on a seat. Unless you like frankenstein style switches!
They do not need exact current to work, they just require the correct connections to work.

In the 700/900 FAQ it gives instructions on how to wire up the electric seats which says once the red and black wires are connected it will work. It will not.

I'll have a look at this see what it says.

I think I'll have to connect both the red and orange wires to the correct fuses in the fuse block to get this to work. i.e red to a 30A fuse, orange to a 15A fuse. I'll have to see what current I'm getting then I think I'll be in business.
The easiest option may be to T into the wires on the drivers side. I'll see tomorrow.

I would definately connect the wires to the correct size fuses & size cable unless you want a fire.

The black ground wire can just attach to the bolt.
I guess the red constant 12V is to retain the 3 memory functions?
cheers, Carl.

If this is the red wire which requires a 30a supply? then the memory function may use power from this, but its main function would be to supply power for a motor & or the heated seats.

[barkster1971]

ok after having a look at the V90 passenger seat wiring diagram from the connector to the seat the orange wire goes to the red "stop" switch then to a relay.The red/black wire joins the orange wire at this relay. From the relay both wires feed the same switches. Therefore I am going to remove the relay and have it so the wires bypass it. I bet the seat will work then! I'll have it working by lunch tomorrow

[barkster1971]

Well I whipped the seat out. Dismantled all the wiring and then put it back together again and it's fine. There's a small relay in the circuit board behind the seats switches that I had a look at but left alone. Connected the wires up and it works fine. Just need to permenantly wire the bugger in now. But at least I've got the four bolts in now!

[czech240]

...but thanks to your sig pic I realised its possible to open the bonnet further than normal when one is working in the engine bay... I first though you had ground off the stops on the bonnet hinges...but upon closer inspection realised the stops are not fixed....nice touch Volvo!

[barkster1971]

I only knew about that after about 7 years of ownership! It does make gettting at the dizzy easier for one thing.

[Big IV]

We are switching out our tan manual seats in our 740 with black leather electric seats. I'd honestly prefer the manual seats but the black seats were the only ones that we could find and they were electric.

We're considering switching over the manual bits.