Thread: Dead at Wauchope - fuel temperature sensor

Limped it in to Wauchope with RAC guy following us. Hastings Diesel Service will be taking a look at it

This isn't going to help you, but I keep a selection of resistors in my tool kit for spoofing ratiometric sensors. These bloody things are so complex that .. well you've seen what a duff sensor can do. As long as you know it's not a real problem, being able to at least get a signal into a plausible range can be handy for "ongoing procession".

Originally Posted by BradC

This isn't going to help you, but I keep a selection of resistors in my tool kit for spoofing ratiometric sensors. These bloody things are so complex that .. well you've seen what a duff sensor can do. As long as you know it's not a real problem, being able to at least get a signal into a plausible range can be handy for "ongoing procession".

Damn good idea. I. guess you'd keep a list of "expected values"?

Originally Posted by Tins

Damn good idea. I. guess you'd keep a list of "expected values"?

Nope, although I do keep a copy of the manual on my iPad and that often has values or voltages listed.

I haven't had to use them in anger, but I did have a play with the water temp sensor one day. I monitored the live value on the GAP and just played around until I got something vaguely plausible. Off the top of my head I couldn't even tell you now what values I have in the box. The beaut thing about resistors is you can just put them in series or parallel until you get something that works. I've got a small 8 way chocolate block and some high temp silicone covered cable in the kit. So I can just hack together whatever is required to bypass/replace the faulty sensor.

Of course it's like having insurance. Since I have the gear in the car I'll never actually need to use it.

Originally Posted by BradC

This isn't going to help you, but I keep a selection of resistors in my tool kit for spoofing ratiometric sensors. These bloody things are so complex that .. well you've seen what a duff sensor can do. As long as you know it's not a real problem, being able to at least get a signal into a plausible range can be handy for "ongoing procession".

Good idea I'm sure I bought one of these from Jaycar but they don't seem to keep them anymore Resistance Wheel | Jaycar Electronics but there are other resistance boxes out there resistance box - Google Shopping and my fuel temp sender is leaking fuel through it.

Just buy a few potentiometers that will let you cover all ranges likely. Eg 1k ohm, 10k ohm, etc.

Then you can select and adjust to your need.

Remove sensor, clean connection socket thoroughly. Attach some "fly leads" to the connection pins, then fill the connection socket with Araldite, this will reseal the sensor. Replace sensor and connect fly leads to existing wiring.

Originally Posted by RANDLOVER

Good idea I'm sure I bought one of these from Jaycar but they don't seem to keep them anymore Resistance Wheel | Jaycar Electronics

I let the smoke out of those one day on a mates boat with a Cummins diesel. The resistors just didn't have the power handling capacity to emulate the oil pressure sender. Remembering you don't need a precise value to get out of trouble, just something in the range of "plausible".