Sanky

1 hour ago, ½cwt said:

I'd never noticed the font difference before in this mod, but at least it is symmetrical with the two outside gauges.  I guess keeping the Boxster gauges avoids some (or all?) of the EEPROM reprogramming and calibration/scale issues for the speedo.

You still need to enable the oil and volt gauge in the eeprom.  But keeps it OEM for thing else.

Just now, ½cwt said:

That's the 996 instrument upgrade then.

Yeah, but using the 3 gauges from the 986.

Would have like to replace the gauge faces for the volt and oil gauge, so it had the correct Boxster font.

Any instrument cluster will fit, as long as it has the same colour connectors on the back.

But if you want it to match your existing one or upgrade to the dot matrix, you will need to check the images or cross check the part numbers.

This is my hybrid version

Just now, ½cwt said:

Yes, it would need to be the newer 2002 onwards instrument cluster to match your car, not the one linked to which is an early model one.

Both types of clusters were fitted, the dot matrix ones were used with factory fitted OBC ones and segment display for ones without.

Just need to make the colour of the connectors on the back are Grey, Green and Blue for the facelift.

2 hours ago, Christopher2110 said:

Morning all!

After a long winter, I've remembered I've still got the issue of a speedo that doesn't work!  After being heavy handed removing the dial fascias and buggering things up I no longer know how fast I am going! 

In an attempt for a temporary quick fix, is it possible to swap out the whole cluster? Something like THIS ?
I have a 2003 S so I understand it needs to be a 2002-2004 cluster from another S.
The mileage will not match but I believe that can be corrected by some programming. I have read that the stock radio will/ can lock out but I no longer have a stock radio.

 

Anyone know if it's a simple plug and play? Is there anything else to consider?

Yes you can swap out the whole cluster to the one you have linked.

But you may to upgrade to the dot matrix cluster like the one in the link below.  Gives a bit more information in the centre display.

2002 PORSCHE BOXSTER S 986 - SPEEDO / INSTRUMENT CLUSTER 98664123700 #SLG | eBay

Have you got OBC?

4 hours ago, TV8 said:

Thinking about this, doesn't connecting the elements in series increase the resistance compared with in parallel if connecting 4 down to 2? I have this memory of light bulbs being brighter wired in parallel than in series. Assuming brighter could also mean hotter, it might explain your lower than anticipated temperatures?

Correct 2 heating elements at 0.8ohm each, wired in series would be 1.6 ohm.

@K.I.T.T. there are 2 connections under the seat for each element disconnect them and measure the resistance.  Or measure like above to check the total resistance.  

Your fault sound like one of the elements is open circuit if the LEDs on the switch are coming on and off.  If you disconnect the elements you will get the same result

Parts list, apart from the heated seats.

Wiring loom as per wiring and routing of your choice, I followed the factory wiring loom best I could.

@TV8, the 986 seats don't have 4 heating elements built into them, there are just 2 heating elements wired in series that end up with 2 wires going to the CU unit.  Hope that makes sense.

11 hours ago, TV8 said:

Do you have 4 heater connection terminals with 2 on the base and  on the back? I only have two, at least as far I can see? 

Anyway, it seems like they are working correctly although not sure what sort of thermostat would be fitted. Timer maybe? 
When I was thinking about this earlier, I was expecting there to be a variable resistance added to change the load and you have a constant load. I was expecting a higher wattage and if it was 55w, that is exactly the rating of a headlight bulb. I would be trying the two settings on a bulb to see what happens! 
Good luck

@TV8, on the 986 seats you are correct there are 4 heater connections, 2 for the base and 2 for the backrest.

Then I mentioned thermostat earlier, its probably not the correct terminology and more like a thermistor built into the CU that measure the temperature.

Are you trying to fit 987 heated seats into a 986?  I think you should be able to do this quite easily if you were to use the 986 CU, switches and wiring.

You may want to start another thread if you are serious about getting the 987 heated working in a 986, as others may benefit from the details.

3 hours ago, TV8 said:

You mentioned the seats have a resistance of 0.8 ohm. My 987 seats have a resistance of 1.3 ohm.

Using the law of ohm V=IR.

Assuming V is 12v and as we have different resistances, we would see different currents in the circuit for our respective seats. Assuming the seat resistance is fixed (my seats have two terminals), the current has to be controlled somehow and must be also measurable at the output of the control unit? With the two settings on the switch, I would be looking for a difference between settings and if possible, absolute values for each with the ammeter in series to the circuit for the current.

 

0.8 Ohm is for each heating element, base and back.  These are wired in series giving a total resistance of 1.6 Ohm per seat, so not far off from you have.

When the seat heater is turned on one seat only, its drawing around 5.8A per seat.  It makes no difference to the current drawn if the seat heaters are set to High or Low.  The only difference for the temperature setting, is that control unit under the seat switches the power on and off to the heating element sooner for the lower temp setting.  So must have built in thermoset in the control unit to monitor the temperature.

Some calculations below using ohms law.

Current drawn 5.8A, Heating Element Resistance 1.6Ohm, Voltage 13.5

5.8A x 1.6Ohm = 9.28V across the heating elements.

5.8A x 9.28V = 53w for the heating elements, which seem correct on google for heated seats in general.

I took some readings with infrared thermometer, on High setting I get a temperature fluctuating  between 22C and 19C.

On the Low setting its around 16C and 14C.

I think this concludes the seat heaters are working correctly and I just trying to compare older technology in the Porsche to my newer technology in the Jaguar.

But if someone can share some temperature reading with a similar device, it would be appreciated.

50 minutes ago, ½cwt said:

So if paired with the correct original switch and the correct wiring it should switch power modes I'd have thought.  You can't just plug in 12v and hope it will work correctly.  The wiring diagram gives you the pin outs for the switch, the control unit and the connector under the seat at least.

Not sure what you are getting at.  But I’ve done the complete wiring from the switch to the seat as per the factory wiring.  The switch is functioning as it should, press once for high, press again for low.  Press the led on the switch to switch off.

I just don’t feel the seats heat up as much I was expecting.

I have not fitted eBay heated seat elements to factory switches.

The control unit is part of the under seat heated wiring loom.  Looks like a relay, but has Pic inside with some other electronics to monitor the temps.

57 minutes ago, iborguk said:

Fair, do you have access to any Porsche diags kit with which you can read the live temp values of the seats ? 

 

 

It’s not that intelligent, there is no diagnostic wiring to any of the heated seat.

32 minutes ago, Menoporsche said:

Or an IR gun thermometer like got popularised during the pandemic?

I do, I’ll see what readings I get with that.

5 hours ago, iborguk said:

There is also the possibility that the heated elements themselves are no longer as effective due to aging. 

I had to replace the heated element for the back rest for a new, when I measured the resistance on the new element it was around 0.8 Ohm.  The other heating elements measure around the same resistance.  So think they are all good.

I can even see the seats drawing current on when the heating is on, which is a around 6A per seat for both high and low setting.  Can also seeing it going on and off as it gets to the desired setting.

Think it might be just the way they are.

9 minutes ago, Jon61 said:

With the 2-stage seat heating in my 986.1, like every other car I've had with heated seats, the hottest setting was too hot for my liking and I'd never use that setting for more than a minute or so. So I'd say the answer to your question is a definite yes, if they're working correctly.

Thanks, I'll have another look at the wiring.  As If I have got something wrong, I've done the same to both seats.

3 hours ago, TV8 said:

My 9x7 seats support two stage heating and this is linked to the ecu or some ecu linked controller.  I think, the 9x6 switches are single versions, ie on or off and reset to off with ignition or power disconnect. 
if you mean the video of the seats into the 986, I haven’t made it to the end of that yet. I decided to instal and sort the heating later. If it was a different one, can you remind me which was it was please?

The 986 heated seats also have 2 stage heating, press once for high heating and a second for low heating.  The switches have LEDS that glow red and orange.

12 hours ago, edc said:

That may be why it's not as hot as you expect? Perhaps some are broken? 

They are factory heated Porsche seats, if either of the elements were broken they wouldn't heat up at all.  I tested all the elements before fitting the seats and had to put a new element for the back.

What are peoples thought who have factory fitted heated seats in there 986 Boxster, do they heat up a lot?

1 hour ago, TV8 said:

I like those switches. Do you have a list of the parts you used and any pictures of the instal please?

I’ll put one together, not difficult to do if you buy the seats with heating elements already fitted.

Just finished retrofitting factory heated seats and I must say I’m not overly impressed with the amount of the heat they give.

I was expecting something like on my Jag where they get really nice and hot, that you have to turn them down.

I am in the process of fitting factory heated seats to my 986.  Doesn't look to difficult  as long as the donor seats have all the wiring and relays attached.

You need to add the wiring from the switches to under the seats, one of these wires is for the backlight of the switches.

A power wire from the seats to the fuse box A6, there is also a ground wire as well, but I think this is already part of the standard loom.

I have not got the car out from winter hibernation so not got around to actual fitting them, but I am ready to go.  I will be trying to keep the wiring as close to factory as possible, using the proper connectors and plugs.

The post below may help and feel free to shout if you need any further help with the diagrams or anything.

Option Retrofit - DIY Seat Heating for a 996t - 6SpeedOnline - Porsche Forum and Luxury Car Resource

27 minutes ago, Sanky said:

should be around 15 kg/h at idle but will vary depending on conditions. If you can read the live value of the MAF, you can remove the oil cap and check that the reading drops to rule out the MAF itself.

Should have added that the reading should be taken with all engine loads off and at operating temp of 90c

Just now, iborguk said:

https://amzn.eu/d/gjcZCNX

Have you tried these out on the round connectors, as I have similar sets and get any of them to fit on the round connectors.

19 hours ago, ½cwt said:

This might help as it gives the wire colours in and out of the connector and shows seat heating too:

and the connector, I'd extracted the red and yellow wire pins (pull out the blue tab you can see) but they are in the correct locations.

 

 

What tool did you use to pull the pins out?  I could do with one of those for my retrofitting of factory heated seats project.

4 hours ago, phazed said:

Does anybody know what the readings should be for the MAF?

should be around 15 kg/h at idle but will vary depending on conditions. If you can read the live value of the MAF, you can remove the oil cap and check that the reading drops to rule out the MAF itself.

If it was working fine before you changed the plugs and epoxied the coil packs, I would start from there and make that electrical connector is plugged in correctly.

But if the coil packs are cracked, would  just replace them as a maintenance item.

New control module arrived today, so did a trial fit and I am pleased to say its all working as it should be...whoop! whoop!

No special control module needed and no height sensors are need, if you use the retrofit wiring loom from Porsche.

I'll post a video up, once its out of winter storage.