Page 1 of 1
Re-wiring temperature sensor and switch?
Posted: Sat Feb 16, 2013 6:54 am
by whiteretta
I'm finally after two years going from a three wire temp sensor to the original temp sensor and temp switch, however since I now have a 3400, where should I relocate the temperature switch to?
With the two wire temperature sensor re-installed, it's already running much, MUCH smoother, I just need to figure out the temp switch to make it all work, lol.
Any help is appreciated!
Re: Re-wiring temperature sensor and switch?
Posted: Sat Feb 16, 2013 2:30 pm
by 3X00-Modified
Just wire it like a 3400 and use the three wire sensor. The other sensor is for the dash, the one that's by the thermostat controls the ECU readings and fan turn on and stuff.
Re: Re-wiring temperature sensor and switch?
Posted: Sat Feb 16, 2013 5:59 pm
by whiteretta
I originally was running this sensor, but had an issue where the car would stutter and stumble horribly upon start up. I switched back to the two wire, and the problem went away?
Re: Re-wiring temperature sensor and switch?
Posted: Sun Feb 17, 2013 6:38 pm
by whiteretta
Well I wired back in the three wire sensor today, with the same wiring as shown in the linked post, and she's back to running pig rich with a stumbling rough idle. Looks like I'll be picking up a new sensor from my work tomorrow, lol.
http://www.beretta.net/forum/viewtopic. ... sor+wiring
Re: Re-wiring temperature sensor and switch?
Posted: Mon Feb 18, 2013 7:58 am
by 3X00-Modified
Then you have something miss wired... I have a stock 3 wire sensor on my car with no issues at all. If it's running pig rich then it has no idea what the coolant temp is so the circuit that should be feeding a signal to the ecu is not wired properly.
The wires on a 96 sensor are Black Yellow and Green. The Black is ground the yellow is 5V and the Green is the wire for the dash. Unfortunately the 96 wiring diagrams show a 2 pin sensor feeding the ECU and call it pin's A and B, A getting the black wire and B getting the yellow wire. later in the harness it swaps to Orange/Black and Yellow... Thats only because its a common sensor ground wire so they use the orange back.
And using typical electrical logic and what this sensor has...
The black wire should go to the black, Gray is a typical 5V signal wire so that should go to yellow and then the blue should connect to the green. The diagram that is on the link you posted has the black and signal, or brown as noted on that one, backwards. Depending on which end he has facing you... If that diagram is trying to show the back where the wires come out its wrong, if your looking at the front of the plug then its right.
Re: Re-wiring temperature sensor and switch?
Posted: Wed Feb 20, 2013 6:57 pm
by whiteretta
I verified that the sensor's wiring was correct, switched out the old three wire sensor for a new three wire sensor and she fired right up, no effort required.
The help was much appreciated!

Re: Re-wiring temperature sensor and switch?
Posted: Thu Feb 21, 2013 7:47 am
by 3X00-Modified
That's good that it was just a POS sensor... less time involved in chasing something.
Re: Re-wiring temperature sensor and switch?
Posted: Thu Feb 21, 2013 10:43 am
by woody90gtz
That happened with me back in '06 too. Installed a 3-wire that was good a couple days, then ran like garbage...returned it for another sensor that also ran like garbage and got fed up with parts store crap. Put the original 2-wire in and it ran great.
Re: Re-wiring temperature sensor and switch?
Posted: Thu Feb 21, 2013 11:12 am
by 3X00-Modified
buy one from rockauto next time... better brand selection...
Re: Re-wiring temperature sensor and switch?
Posted: Fri Feb 22, 2013 10:47 am
by whiteretta
I had one of those "bad out of the box" sensors, just never thought it would've been the sensor, lol. Two years later... finally fixed...