Can we develop a field test for electrical items?

Post by **scot850** » 22 Oct 2017, 12:51

Following on from my heating system testing it has made me think that for those of use who are electrically 'challenged' it would be great if those in the know could help us develop an 'In-Field' simple test process for electrical parts or sensors that we could carry out in a junkyard with a basic electrical meter or test 'kit' of some sort that would help us have a better chance to bring home good parts for replacement or storing for spares.

I am working on the cabin temperature sensor for the 98-00 V/S/C cars, and I think there is the info on a thread jreed linked to that thread that may give a simple resistance test for the in duct sensor for the heating system (the one by the cabin fan). We can also either find or develop one for the ETC/ECT(?) coolant sensor from the info out there and the 2 temp sensors at the front of the car for outside temp for the car read out and the one for the engine sensor (similar/same part). Some may need to be 850 specific (different cabin sensors on ECC units x 2) or V/C/S70 specific.

Then we could add possibly cam and crank position sensors (I know there is a resistance range for cam sensors somewhere).

Some test for some electrical parts may only be a continuity test but still may be invaluable when at a junkyard.

The PnP's where I live do not refund payment for parts and only give you an in-store credit, which may be fine for some folks but I'd rather not (cheap Scotsman).

Any thoughts on this?

Neil.

PS78 · Post by **PS78** » 23 Oct 2017, 12:45

Here's a thought. With the ability of android and IOS phones to complete nearly any task anymore, including acting as multimeter's with the use of peripherals. What if someone developed an app with a database of all the electrical ranges across the line of different Volvo vehicles? So let's say you connect the fused test leads to your phone then bring up the app and enter year, make, model and the other specifics. After that a drop down of electrical items or sensor types that you can select from, with an additional step for verifying component manufacturer (Bosch, Denso, etc.) The App would already have the different acceptable values for each component when you perform the test with variations in temperature taken from the phone itself to ensure accuracy with components that are temperature sensitive, like the coolant temperature sensor for example.The app would say good or bad and give the reading as well as the range for each component. Maybe there already is such an app? I don't know. Sounded good.. Maybe a budding programmer could serve it up. This is what happens when I overdue it with the coffee.

Post by **tryingbe** » 23 Oct 2017, 12:59

Temperature sensors is a thermistor, its resistance changes at different temperature, this can be tested with a multi-meter easily.

Crank/Cam sensor is usually three wires, one for power, one for ground, and one for PWN signal. It usually shielded. Not so easy to test without the parts be installed.

TPS/MAP sensor have three wires, one for power, one for ground, and one for signal which changes depends on throttle position or pressure. Can be tested, you can provide a 5 volt battery and ground and have a multi-meter handy.

http://www.msextra.com/doc/pdf/html/Mic ... e-3.4.html

Post by **scot850** » 23 Oct 2017, 13:19

Interesting input and thanks. As I am not electrically biased, the link to megasquirt website I use for what information? The basic test info on each section or is it something that can be used in the field for testing somehow?

I appreciate that cam/crank sensors cannot be really tested unless in use for the intended purpose, but can anything be gained from a simple continuity test to reduce the chance of a flimsy part being damaged during removal at a junkyard?

Thanks,

Neil.

Post by **scot850** » 23 Oct 2017, 13:22

Apologies for missing responding your thought provoking input PS78. That would be the ideal junkyard raider tool, but would anyone be bothered to generate one for such old vehicles. But I really like the way you are thinking for those of us electrically challenged with a simple good/bad output.

Neil.

PS78 · Post by **PS78** » 23 Oct 2017, 14:13

I think as far as being bothered sure, the concept might be a little out there but an enterprising developer might see the potential to cover a broad range of makes with a similar format and make out decently. Considering they have virtually no capital needed and really only requiring there time and skill. With most of the yards having " no returns on electrical" posted, an application able to walk nearly anyone through testing and verification could pay for itself very quickly.

Post by **matthew1** » 23 Oct 2017, 15:05

Let me know what I can do to help.

Phones are nice... app approval can take time however. Then there's development.

What about Blackberry Pi? Those devices are simple, powerful and very cheap, and no approvals needed. There was a thread here yesterday or Saturday about one used for bench testing.

PS78 · Post by **PS78** » 23 Oct 2017, 16:17

Your raspberry pi idea is excellent. Lots of Linux distributions for those little guys. I've been interested in them ever since I saw that they're being used in smaller offshore buoys to control the instrument arrays, transmitting data,etc. The potential is definitely there.