NB Mk2.5 Heated Seat wiring

I can’t seem to find a definitive answer to this, and not sure where to look on the car for confirmation.

Do MK2.5 models that were originally supplied with unheated cloth seats have the necessary wiring in place to fit heated leather seats instead? I know that the switches would need to be added on the dash, again assuming the connector is already present in the area below the heater controls.



I believe not but someone a few years ago did a post with the wiring required for Mk2.5 heated seats on a car without the wiring factory installed.

I bought a pair of heated leather seats for my mk2. The seller gave me a small wiring loom for them, so I assume it’s not part of ithe main wiring harness.

I’ve fitted the seats but not yet tried to wire the heaters up.

I’ve recently put heated leather seats in my mk2. Got the switch from the same donor car. Haven’t done anything about wiring them up yet. 

Thanks for all the helpful responses. To partly answer my own question…

Having now fitted the heated seats I can confirm that what I assume to be the necessary wiring is already present in the connectors fitted to the car - black + green on the drivers side, black + green/red on the passenger side.

Also a 20A fuse is installed in the fuse box in the position marked for heated seats. However I haven’t yet had chance to determine where the underseat wires go to (presumably to relays if fitted) and the connector for the switches in the dash doesn’t appear to be present.

In just trying to get some retro fitted heated seats working on my NBFL. The wiring for the seats themselves is there (and the seats are plugged in), but there is no sign of plug/cable for the switch. I appear to have some spare plugs for relays up by the fuse box. What am I missing? Does anyone know what I need?

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I have the solution to this problem, but have not yet costed it. I am about to produce a loom to connect between existing wiring and the heated seat switches, which is not normally supplied with other parts available on known sources.

The ‘Dash loom’ does contain fuses (two are involved) which are fitted already to the main fusebox, plus relay bases and connectors under the seats, but does not contain the missing link between the dash loom and the heated seat switches. That is the key to the puzzle, which as I said, I’m working on.

It’s taken a lot of time figuring out what’s involved and what connections are required, not helped by the fact the electrical diagram is rather misleading, showing apparently a four pin connector which turns out to be a much larger item instead. An Email from a guy in Holland has been a big help, but he had the benefit of a donor ‘sport’ model from which he could extract the loom, and everything else needed.

Mist owners buying leather seats from scrapped Sport models will also need to source the two relays, and the heated seat switches (preferably with short ends of wiring still attached) and then add the loom I aim to produce.

There is a way (shown on Nutz) of doing all the wiring yourself, which is unnecessary, and also not professional - as the writer admits. Most of the wiring is already there, it just needs this missing link.

I also intend to produce a full instruction sheet, so if you can follow it, and have some electrical experience, you can do it yourself, but as that takes time and effort to produce, it will be at a nominal cost.There are still additional costs involved - e.g. the parts and some special tools.

Right now, it’s a case of “watch this space” till i’ve completed the first issue, where a very patient owner is also waiting for the final result. I’m also waiting for some additional info (correct part numbers) as sources shown on Ebay are vague and misleading. Once I have that, I’ll publish it on here - relay part numbers are one example. I have no intention of ripping anyone off, it’s a genuine attempt to help owners achieve what they hope for, a working heated seat (two of them!) And I would add - I’ve spent hours and days researching this, not helped by works diagrams.

Thanks. Its really odd why they partially wired the seats. You would like to think you could plug in a loom extender and that would sort it, but life is rarely that simple.



If anyone has the connector for the heated seats switch and the relays please let me know.


I was originally told, shortly after buying my car, that all wiring on Mk2.5’s included all wiring necessary, - advice I’ve been acting on for years.In this last two years, that advice was not entirely true, as while some looms have all wiring in them, interconnections are often missing between one loom to another. Take the dash wiring loom as an example, it appears it does contain all wiring associated with any switch or other device fitted to the dash, which is terminated at one of several ‘common connectors’. THe main fuse box (under the dash) for example has it’s own common connector, which means all fuses are provided in the fusebox for any additional requirement, but the connections between it and the dash loom are made between it’s common connector to the main dash loom connector via add-ons, usually made at the factory.

So the dash loom contains front fog lights, which were only fitted in early models to Sport models, so in that case connections were made between the dash loom, and another feeding the engine compartment. Not sure this holds true for all Mk2.5’s, as I have enough problems with the heated seats, however, if anyone wishes to know, I can take a look at that in the manual. (Later!) I do know that wiring extends to connectors which still require a short cord for the actual fog lights - as that’s shown in the manual.

Andrew at Autolink did kindly give me a part number for a works loom to connect between the main dash loom connector (X05) to the heated seat switches, but as he gave me two part numbers I’m unsure which is correct for an NBFL. Apparently this loom contains a pin for each of the four wires that plug into X05, so makes the work easy enough.(X05 has empty spaces where the additional pins fit) BUT - I have doubts about availability now, seeing as the model is between 13 to 17 years old, and I wonder what stock is left on Mazda’s shelf. Also time delays, anything in stock at the European depot (which take up to a fortnight to get to a dealer) and will take even longer if ordered from Japan - that’s for sure. If there’s not one left, then it needs a special order placed on an individual supplier to have one made, and that will certainly double the cost IMHO. “One-offs” aren’t cheap.
Anyone chopping a loom out of an old car - along with switches and seats, isn’t going to think about pulling the pins out of connector X05, so will probably cut the wires away from the connector, leaving the pins still inside. That makes connector more difficult, so anyone doing this from scratch has to connect the new wires to the relay base wiring, which is what I’m presently thinking of doing. However, if I can locate a source for these pins, then the fitting job becomes a lot easier. This is the type of info that’s elusive to find,as are part numbers, relay ratings etc. - none of which appear in the manual I have.

At a quick guess, there’s already several owners who asked for advice, and based on information given to start with, and what is visible in the manual, I told them all to look for a four pin connector behind where the seat switches fit, so until recently, I gave up, as most appear to have used the Nutz info to add the wiring themselves, ignoring the fact that the OEM wiring is 80% still in their cars. This way also ignores the fact that thore are two separate fuses involved, and advises tapping off the Cig. lighter instead.
Another version I read some time ago states that the headlight circuit is a good supply, obviously not thinking about cold winter nights, when you may need both at the same time!

I believe that certain sub looms that connect say the fuse box to a specific extra used on some cars was as you say made at the factory but did not in the end make it into the overall parts list.

I have been wrong in the past with my guesses.

The instance I can be sure of is that there is a bolt and washer that holds the handbrake cable receptical on the rear calipers of the MK3.

The workshop manual does not have a torque for the bolt, nor does the Mazda parts catalouge for the rear brake assemble show show this piece of steel that acts as the recepticle or the bolt and washer in question.

As aways some things just get missed out of the documentation.

There is a major problem on a number of North Sea production platforms where tweeks have been made to major control systems and the people who made these tweeks in the late 1990’s have now retired or moved on and the knowledge has been lost for ever. It happens in all walks of life.

Eddie (quote) “There is a major problem on a number of North Sea production platforms where tweeks have been made to major control systems and the people who made these tweeks in the late 1990’s have now retired or moved on and the knowledge has been lost for ever. It happens in all walks of life.” (unquote)

Frankly as a self taught control panel builder i have repaired/ fixed several panels built by larger companies than me, with some silly mistakes. Problem basically is, panels are designed by so-called experienced control experts, and built by morons, who most of the time can follow drawings, but cannot see mistakes made, with the end result, someone has to go onsite to sort the problem out. Fortunately, in my case, I never became involved in oil rigs, so my experience relates to general industrial equipment installed on the mainland (or Ireland in one instance) One example, a panel built by someone else was supposed to give mine a ‘handshake’ to say when I started a conveyor. They had two guys on site (both supposedly engineers) who claimed it was my panel at fault, they even pulled my wiring out of my panels trunking to find the non existent fault they claimed was mine. To say I was annoyed, is putting it mildly. I told that that they weren’t sending me the handshake needed, and proved it, without going into their panel at all. That was a Saturday morning, and I was already working on another panel. I left the site, telling them when they’d sorted out their problem, to give me a ring and I would come back. Come Monday, the site manager rang me at home, and queried the end result of what had, or hadn’t happened. I told him. He then asked me if I would go back to site (near Boston) and cure it, they wanted to start production, and the other company still insisted it was my fault. I already knew what the problem was, they had installed a wrong terminal block to one of their relays, and it was N/C, instead of N/O, so I took another terminal block with me, changed them over and switched both panels on. Everything worked fine. Never heard another word from anyone. You live and learn.

  • I commented on here a while back that I often felt I could write a book, which did receive some encouragement to “DO IT!” Thinking about it, I could write more than one, a lifetime of various occupations, circumstances and even National Service. A book full of chapters is not enough! - One day maybe - - - - .

Right - late I know, but costing now done. Final information now completed also. I won’t go into the time spent on this, but the majority of that will be written off, at my cost. I still have to finish the instructions, but again, they will be at my cost. A nominal charge of £6.33 is included in prices shown below, which hardly pays for the hours spent in one day, never mind the weeks. Profit? - Ne way, I’d need twenty orders to show £5 at best. – My normal last SE rate was £12.50 per hour, and at a rough estimate, I’ve spent over 50 hours figuring all this out, even with some valuable help from others. This will give you an OEM solution, or as close as I can get. If you object to paying for any of this, then the alternative is contained on Nutz Forum, but you need to buy everything yourself, at the price of wiring plus relays - you can get from Halfords, or other sources. But – bear in mind this IS NOT an OEM solution, designed by a self-confessed non-electrical person.
So - at ‘giveaway prices’ these are the prices below, bearing in mind I am NOT supplying either Relays or Heated seat switches - complete with switch connector and wiring still attached, (a minimum of 4" - 100 mm is needed.) All items which you need to get from E Bay, Autolink, or any other breaker or scrapyard you are aware of. As a guide, don’t pay more than £6 to £8 each for relays, and while you can expect switches to cost more, I wouldn’t spend more than £25 on any second hand one. Don’t forget, delivery may cost more.
For anyone who say they have an OEM loom already supplied (Paul W in mind) - along with relays and switches, then I would suggest you check this - The loom should come complete with a heated switch and switch connector at one end, and I suspect, a pair of wires cut off from elsewhere, coloured Grey/Red stripe and Red/Black stripe which need to connect to the same wire colours present on the Headlight height adjustment switch - to the right of the heated seat switches. On the longer end of the loom, the wiring should end with an oblong male pin on each of four wires - these fit into empty slots on the main (X05) connector, for which I can send you a photo of where each pin (and coloured wire) these fit into to. PLUS - don’t forget - two relays. If the male pins are missing, (new spare pins are NOT available) then you need the full instructions, and six ‘tap’ connectors to finish the job. Cost? See below. Any additional wires in the OEM loom are not needed.(PM me with your home address, plus payment for the extra info. - and I 'll send it. - I just need an email address for the Photo if the male pins are still attached to the wires.

For anyone needing the new loom, there’s four prices, one for those intending to solder all connections (not recommended- safety concerns) and for those less adventurous, but needing a simple solution, there’s a higher cost, for all necessary ‘crimp’ connectors - with or without a crimp/ stripping tool), which adds to the overall mailing cost - doubles the weight. If you already have Crimp and Stripping tools, then you will not need the combined crimp/stripping pliers.

OEM loom in your possession, but no male connector pins included? - £7.50
Soldering all joints? - £9.80
Using crimp connectors - £12.50
Added cost of a crimp/stripping tool - £5.50 (with any order)
Costs include mailing envelope and first class postage. (my cost - around £2, or £3 with crimping. stripping pliers)

  • Payment- I don’t have a PayPal account (yet) so payment by cheque preferred, but no order dispatched till individual cheques are cleared.
    You will need a good pair of general type pliers, 8"-10" preferred. (Bigger the better) and a good pair of strong scissors, or a pair of side cutter pliers. - ‘End’ cutters are useless. If, lIke Paul W - you have an original Mazda OEM loom, complete with connector pins, then you will need a pair of good needle nose pliers. Anyone intent on soldering will need a roll of good quality electrical insulating tape to cover all joints.

Three looms reading for mailing, order fast! - Don’t forget to order crimping/stripping pliers if needed.

Just realised, the header for this thread says “NB Mk2.5 Heated Seat wiring”. Strictly speaking my posts refer to an NBFL (Facelift version) 2001 -2005, not to an NB (Mk 2 - 1998-2001). However, if the wiring includes all wiring including fuses (SEAT and A/C) and heated seat connectors in place under the seats, then you can include the Mk2 (NB) with this post.

I Just wanted to make it clearer.

Excellent piece of work Gerry.

Have you managed to sort this yet?? As it’s something I could well be interested in it