Mattsuffolk Posted April 2, 2017 Share Posted April 2, 2017 Hi all, I'm in the process of fitting a Nige MS kit to my '88 RRC. As I'm replacing a flapper system, I have fitted a hot wire top end (from Nige) which came with a TPS with the Blue/Brown/Green wire colours, and I cannot find the correct information regarding which colour is which related to the red/green/yellow of the MS wiring. It is in Nige's manual, but there is a typo and it mentions the green TPS wire twice and no mention of the brown, found some info online but that contradicted the manual. Have spent a while searching online before asking and couldn't find the answer. Could someone let me know the correct wire configuration please. Also, on a side note, is the PWM valve polarity sensitive? I'm assuming not as I can't find a definite answer online or in the manual And one last thing (promise), the feed to the temperature gauge in the instrument cluster is a totally different sensor on the hot wire top end (small with a bullet connection) than the flapper (larger with a spade termainal), I hoped to just fit the flapper one in place of the Hotwire one but they are a different size thread, can I just connect the Hotwire sensor and all will be well?? Thanks Matt Quote Link to comment Share on other sites More sharing options...
Quagmire Posted April 3, 2017 Share Posted April 3, 2017 On your tps the middle pin should be signal out, one pin will be +5v in (sometimes called Vref) and the other pin will be earth. On MS the Vref comes from pin 24, the middle/signal connection into pin 22. I would make a guess that the Flapper wiring is such that red is Vref, which leaves yellow as earth and green as signal? Bowie or Fridge should be able confirm or deny this! Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted April 3, 2017 Share Posted April 3, 2017 I suspect the blue/brown/green is likely to be an aftermarket TPS, I've not come across another version of OE fitment colours. It is likely though, that the outer wires are ground and 5V, and the centre signal. Easy way to check it if you have a multimeter (I don't know the actual figures here, just making an edumacated guessitmate): Set it to resistance/ohms Put a probe on each of the outer wires, should read quite a high resistance, maybe around 5KOhms Put a probe to one outer wire, and the other to the centre wire, should be around 50-500 Ohms. Open the throttle, the resistance should change You've at this point confirmed the middle wire is signal, if it doesn't do this, then try other combination of wires, first find the pair that give you the high resistance, then the other is likely the signal. The ground/0v line goes to the 'outer' wire that give you a LOW varying resistance between the signal wire and itself. The 5V wire goes to the 'outer' wire that gives you a HIGH, varying resistance to the signal wire. PWM valves are not generally polarity sensitive, assuming a 2-wire. I can't confirm or deny the temp sender compatibility, I would suggest you just try it, and see what it reads, you may be in luck. I have had a look but can't find the sender specs anywhere. HTH Quote Link to comment Share on other sites More sharing options...
Mattsuffolk Posted April 3, 2017 Author Share Posted April 3, 2017 (edited) Thanks for the replies, I will stick a meter over it tonight and see what I can find out. Edited April 3, 2017 by Mattsuffolk Quote Link to comment Share on other sites More sharing options...
Mattsuffolk Posted April 3, 2017 Author Share Posted April 3, 2017 Right, all tested and worked out, I'll summarise below as to hopefully help someone in the future: TPS Green - Signal - MS Red TPS Brown - Ground - MS Green TPS Blue - +5V - MS Yellow 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted April 3, 2017 Share Posted April 3, 2017 Excellent Quote Link to comment Share on other sites More sharing options...
Mattsuffolk Posted April 11, 2017 Author Share Posted April 11, 2017 On 03/04/2017 at 9:42 PM, Mattsuffolk said: Right, all tested and worked out, I'll summarise below as to hopefully help someone in the future: TPS Green - Signal - MS Red TPS Brown - Ground - MS Green TPS Blue - +5V - MS Yellow Having just had it powered up and running, I've discovered that this is in fact incorrect. My TPS was reading backwards... The correct arrangment should be (I had the ground and reference voltage round the wrong way): TPS Green - Signal - MS Red TPS Brown - +5V - MS Yellow TPS Blue - Ground - MS Green I did try and edit the original post but it wouldn't let me, maybe a mod could change it and delete this post? Quote Link to comment Share on other sites More sharing options...
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