FridgeFreezer Posted November 28, 2019 Share Posted November 28, 2019 Does anyone have the resistance measurements (Ohms / temperature) of the GAUGE sender (not the ECT for the ECU) for early P38's? I was sure it was in the RAVE manual or something but jiggered if I can find it Quote Link to comment Share on other sites More sharing options...
elbekko Posted November 29, 2019 Share Posted November 29, 2019 Can't find it... not even mentioned in the BeCM docs. Quote Link to comment Share on other sites More sharing options...
Blanco Posted November 29, 2019 Share Posted November 29, 2019 Found this for you, ... any good? Table Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 29, 2019 Author Share Posted November 29, 2019 2 hours ago, Blanco said: Found this for you, ... any good? Table That's the ECU coolant sensor (2-pin), I'm after the gauge one (single pin). Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted November 29, 2019 Share Posted November 29, 2019 I've only ever seen figures for the Ecu sensor. Quote Link to comment Share on other sites More sharing options...
Blanco Posted November 29, 2019 Share Posted November 29, 2019 Forgive a mere mortal wot hasn't had a V8 now for many a long year......... Apparently Rave does reference it somewhere:... saw a reference to section 19 somewhere? In the Rave manual, it shows a picture of two engine coolant temperature sensors, but in the description, it just talks about one (my guess it is talking about the one with the single bullet connector. It says it should measure 28k ohms at -30 degrees C, 300 ohms at 85 degrees C, and 90 ohms at 130 degrees C.What is the other sensor for (the one with a two prong connector)? Found the above comment Here Also found This and This too, on the basis that the sindle pin sensor is AMR1425, 'green' which I think is correct. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 29, 2019 Author Share Posted November 29, 2019 Thanks Blanco, hadn't figured it as the same as earlier models but that likely leads to a more informative section of the RAVE manual... Quote Link to comment Share on other sites More sharing options...
TSD Posted November 30, 2019 Share Posted November 30, 2019 AMR1425 Coolant - Disco/RRC/Def 3.9 4.0 4.6 around 96-99 Also 300tdi 'GREEN' sensor Also Td5 RoW Spec 136ohms 'cold' 17 ohms 'hot' CI XTT109 Green 1/8x27NPTF Quote Link to comment Share on other sites More sharing options...
TSD Posted December 1, 2019 Share Posted December 1, 2019 Hmm, I cut and pasted the above from my notes files, I should have read it first - I have a second file in my archive with numbers that much more closely match the aulro link that Blanco posted. As a penance, tomorrow I will put the kettle on and measure one....again, and this time I'll try not to lose the test data Quote Link to comment Share on other sites More sharing options...
TSD Posted December 2, 2019 Share Posted December 2, 2019 (edited) Measured a new Bearmach AMR1425 sensors today. Also did AMR3321 and ERR2081 since they were handy. Posted here so they don't get lost again. (First column is Temp in C, Second is Resistance in Ohms. Open in a text editor if you don't do spreadsheets.) AMR1425.csv AMR3321.csv ERR2081.csv Edited December 2, 2019 by TSD 2 Quote Link to comment Share on other sites More sharing options...
TSD Posted December 14, 2019 Share Posted December 14, 2019 Just for completeness, added ETC8496 to the list. This might be a useful one for someone, as it's very close to AMR3321 in performance, but packaged like ERR2081, so fits the sensor boss hole in the middle of the 300tdi head. Might be a useful conversion part for someone? ETC8496.csv 1 Quote Link to comment Share on other sites More sharing options...
owenduffy Posted March 15, 2021 Share Posted March 15, 2021 (edited) Fixed images pasted, ignore last. Thanks TSD for measuring and publishing the NTCs above, I dips me lid to ya! I calculated two point R25/B models for each using Two point thermistor calibration . They provide a simple comparison basis. Owen Edited March 15, 2021 by owenduffy 2 Quote Link to comment Share on other sites More sharing options...
owenduffy Posted March 15, 2021 Share Posted March 15, 2021 I might mention that if you were trying to fabricate a sensor (eg in a stud to suit a foreign engine), R25=2k2 B=3950 thermistors are not too hard to obtain and might be a good enough substitute for AMR3321, ETC8496, ERR2081. Owen Quote Link to comment Share on other sites More sharing options...
owenduffy Posted April 5, 2021 Share Posted April 5, 2021 (edited) So, putting this information to good use... The question here is whether in a particular vehicle, the dashboard gauge and ECT sensor are compatible. 1. 'cold' resistance of the ECT with wire removed is 2730 ohms at around 20C. This hints the ECT sensor is unlikely to be a AME1425 but one of the others mentioned (which are fairly similar). 2. Connecting to parallel resistors for total R=155 ohms yields the following: 3. Connecting to parallel resistors for total R=27.5 ohms yields the following: d 4. Calculating the expected temperature of the AMR1425 at 27.5 ohms from the constants above, we get: ... which was bang in the middle of the red zone. This gauge appears to be compatible with the AMR1425 ECT sensor, not the one fitted to the engine. This seems to be the result of an unprofessional / half baked conversion of a petrol vehicle to a diesel engine. Owen Edited April 5, 2021 by owenduffy Quote Link to comment Share on other sites More sharing options...
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