Connector identification - help please

Blink · 26th April 2019, 11:36

Does anyone recognise the two big grey 20-pin connectors on the left in this pic? They're tucked away to the left of the cupholder/cigar lighter/ashtray unit and were wrapped together with foam tape.

They appear to be just for joining wires together - i.e. they don't plug into anything.

Far left - 7 black wires (1 heavier than the rest)
2nd left - 8 red/white wires, one of them looped (1 heavier than the rest)

I'm trying to find a K-bus wire to tap into but I can't find any red/white wire that has yellow dots. I also need a switched live and a ground. (All three are needed for the e-Zee K-bus temperature gauge).

suzublu · 26th April 2019, 11:46

The K-bus wire is amongst the harness to the radio if that helps?

Blink · 26th April 2019, 12:38

Thanks for the info - I just had a look and one of the red/white wires on the green connector has a yellow dot, although you can't see it in the pic below. I might be able to tap into it further upstream where there's a bit more slack as it goes into a huge harness adapter plug (which converts from a Harmony head unit to a Symphony).

Any ideas on nearby earth and switched live wires?

I wonder if those are earth wires going into the big grey connector (the 7 black wires in post 1 pic)? That would be handy - it's just inches away from where the temp gauge circuit board will be.

raykay · 26th April 2019, 12:58

The grey connectors in the first picture are just joints, the Black cables are Earth connections, the Red/White are illumination connections (for switches, gauges etc.).
The K-Bus cable is in the green connector, switched live is Light Green/White in the grey ISO connector.

Blink · 26th April 2019, 13:23

Quote:

Originally Posted by raykay

The grey connectors in the first picture are just joints, the Black cables are Earth connections, the Red/White are illumination connections (for switches, gauges etc.).
The K-Bus cable is in the green connector, switched live is Light Green/White in the grey ISO connector.

Aha, excellent - thanks Ray!

So I'll tap in for the e-Zee temp gauge circuit board as follows:

K-bus - green connector (Red/White/Yellow wire)
Earth - big grey joint thingy (any Black wire)
Switched live - grey ISO connector (Light Green/White wire)

I do like short cable runs.

Blink · 29th April 2019, 13:22

I've hooked the gauge up as per post 5 and I'm not getting a temperature reading.

When I turn the ignition on, the PCB beeps four times and the display shows 888.C.

As soon as I start the engine, the display turns to .C (no numbers showing) and it stays like that - i.e. I never get any numerals before the .C (except the initial 888 of course).

Any ideas chaps?

PS. None of these items are in the car at the moment (not that it's likely to make much difference):

- IPK
- Radio (Symphony head unit with navpack panel)
- Aircon/heater control panel

milford man · 29th April 2019, 15:16

Not sure but what creates the K-bus? Is it in the IPK by any chance?

Regards John

Blink · 29th April 2019, 15:42

Quote:

Originally Posted by milford man

Not sure but what creates the K-bus? Is it in the IPK by any chance?

Regards John

I don't know to be honest. I'm trying to find out using RAVE / Haynes but no luck so far. At a guess I'd say it's more likely to be the ECU or BCU rather than the IPK.

Blink · 29th April 2019, 16:23

Ah, perhaps it is the IPK (lack of) - this video says: "The Rover 75 uses three bus systems that are linked together by the instrument pack".

Play from 7m 50s (ish) - https://www.youtube.com/watch?v=MVEgz8PccqE

milford man · 29th April 2019, 17:03

I can't see how it can work with out the IPK. Its the IPK that transmits the engine temperature. Its been a long time since I worked on a Rover 75 but from a quick look at the wiring diagrams. Engine coolant sensor is wired to the ECM which talks to the IPK via Can Bus. Engine temperaure is on the K-Bus (via IPK).

Regards John

26th April 2019, 11:36	#1
Blink Posted a thing or two Rover 75 Saloon Join Date: Apr 2019 Location: Under the car Posts: 1,840 Thanks: 210 Thanked 244 Times in 221 Posts	Connector identification - help please Does anyone recognise the two big grey 20-pin connectors on the left in this pic? They're tucked away to the left of the cupholder/cigar lighter/ashtray unit and were wrapped together with foam tape. They appear to be just for joining wires together - i.e. they don't plug into anything. Far left - 7 black wires (1 heavier than the rest) 2nd left - 8 red/white wires, one of them looped (1 heavier than the rest) I'm trying to find a K-bus wire to tap into but I can't find any red/white wire that has yellow dots. I also need a switched live and a ground. (All three are needed for the e-Zee K-bus temperature gauge).

26th April 2019, 12:38	#3
Blink Posted a thing or two Rover 75 Saloon Join Date: Apr 2019 Location: Under the car Posts: 1,840 Thanks: 210 Thanked 244 Times in 221 Posts	Thanks for the info - I just had a look and one of the red/white wires on the green connector has a yellow dot, although you can't see it in the pic below. I might be able to tap into it further upstream where there's a bit more slack as it goes into a huge harness adapter plug (which converts from a Harmony head unit to a Symphony). Any ideas on nearby earth and switched live wires? I wonder if those are earth wires going into the big grey connector (the 7 black wires in post 1 pic)? That would be handy - it's just inches away from where the temp gauge circuit board will be. Last edited by Blink; 26th April 2019 at 12:43..

29th April 2019, 13:22	#6
Blink Posted a thing or two Rover 75 Saloon Join Date: Apr 2019 Location: Under the car Posts: 1,840 Thanks: 210 Thanked 244 Times in 221 Posts	No temperature (numerals) showing I've hooked the gauge up as per post 5 and I'm not getting a temperature reading. When I turn the ignition on, the PCB beeps four times and the display shows 888.C. As soon as I start the engine, the display turns to .C (no numbers showing) and it stays like that - i.e. I never get any numerals before the .C (except the initial 888 of course). Any ideas chaps? PS. None of these items are in the car at the moment (not that it's likely to make much difference): - IPK - Radio (Symphony head unit with navpack panel) - Aircon/heater control panel Last edited by Blink; 29th April 2019 at 13:35..

26th April 2019, 11:46	#2
suzublu This is my second home rover 75 1.8 vvc club se wedgwood blue Join Date: Aug 2009 Location: Seaton Carew Posts: 26,920 Thanks: 65 Thanked 7,142 Times in 4,642 Posts	The K-bus wire is amongst the harness to the radio if that helps?

26th April 2019, 12:58	#4
raykay I really should get out more....... Now Other Manufacturer Join Date: Nov 2006 Location: Co. Kerry Posts: 2,786 Thanks: 16 Thanked 310 Times in 283 Posts	The grey connectors in the first picture are just joints, the Black cables are Earth connections, the Red/White are illumination connections (for switches, gauges etc.). The K-Bus cable is in the green connector, switched live is Light Green/White in the grey ISO connector.

29th April 2019, 15:16	#7
milford man Gets stuck in Jaguar XE Prestige Join Date: Oct 2010 Location: Coventry Posts: 540 Thanks: 155 Thanked 109 Times in 101 Posts	Not sure but what creates the K-bus? Is it in the IPK by any chance? Regards John

29th April 2019, 16:23	#9
Blink Posted a thing or two Rover 75 Saloon Join Date: Apr 2019 Location: Under the car Posts: 1,840 Thanks: 210 Thanked 244 Times in 221 Posts	Ah, perhaps it is the IPK (lack of) - this video says: "The Rover 75 uses three bus systems that are linked together by the instrument pack". Play from 7m 50s (ish) - https://www.youtube.com/watch?v=MVEgz8PccqE

29th April 2019, 17:03	#10
milford man Gets stuck in Jaguar XE Prestige Join Date: Oct 2010 Location: Coventry Posts: 540 Thanks: 155 Thanked 109 Times in 101 Posts	I can't see how it can work with out the IPK. Its the IPK that transmits the engine temperature. Its been a long time since I worked on a Rover 75 but from a quick look at the wiring diagrams. Engine coolant sensor is wired to the ECM which talks to the IPK via Can Bus. Engine temperaure is on the K-Bus (via IPK). Regards John