Shielding on crank sensor wire

pavel5 · Post by **pavel5** » Mon Dec 07, 2009 1:30 am

I am a beginner gentlemen so be kind.... Just looked at the crank position sensor for my homemade trigger wheel. When I pulled the plastic covering off the sensor wires, I noticed that the pair of wires (blue and grey) were wrapped in a wire shielding. The shielding was a simple wrap around, nothing as fancy as the braided shielding on cablevision wire.
Can anyone tell me where to buy a suitable paired shielded wire so that I hook up the sensor?

Should the shielding be grounded? If so, does it matter at which end and where the grounding is?

As I said, I'm a beginner!

Thanks

NITROPIXIE · Post by **NITROPIXIE** » Mon Dec 07, 2009 7:01 am

Hey pavel5

I think people have used microphone cable for shielded wire in the past. Search it and you should find something. I personally only use twisted pair and don't have an issue. The best place to ground the shielding is at the EDIS end. Not the sensor end. If you were to ground both ends and you didn't have a very good engine earth then the starter motor current could pass down the shielding and obviously it couldn't take the current so would melt, just to keep in mind.

Hope this answers yours questions

pavel5 · Post by **pavel5** » Mon Dec 07, 2009 4:58 pm

Thank you Nitropixie: Microphone wire looks like a good solution.... it seems to come in paired 22 gauge wires with braided copper shielding. The copper shield is better than the steel (Ford) shielding but will 22 gauge be sufficient?

Appreciate your help!

Pavel in Canada

NITROPIXIE · Post by **NITROPIXIE** » Mon Dec 07, 2009 7:46 pm

It should be sufficent. The signal is only a small voltage, around 2-3v and current is negligable so should be fine.

DannyP · Post by **DannyP** » Tue Dec 08, 2009 2:52 am

+1 Nitro. If you have a wrecking yard where you can pull stuff yourself, I am partial to Subaru OE wire. It is thicker than 1/4", heavy abrasion proof jacket. There are a few on the engine and some go from the ECU to the trans also.

Dean924s · Post by **Dean924s** » Tue Feb 02, 2010 4:24 am

I got a real of shielded wire from radio shack was short $$$

cng1 · Post by **cng1** » Tue Feb 02, 2010 9:32 pm

A few words of caution with regard to using microphone wire. The first is that it isn't generally designed to be oil/fuel resistant so over time it will degrade. Microphone wire also tends to have very fine strands so can be tricky to solder/crimp and because it is relatively flimsy you need to work hard to ensure that you have adequate strain relief or it will work fine for a bit, then the cores will start to let go and you'll be left with a difficult to diagnose intermittent poor running problem.

It is also worth correcting the misnomer that "it's just a couple of volts" - the voltage increases pretty much linearly with RPM, so on cranking 2 volts may be all you see but in use 50 volts isn't unusual and we've seen well over 150 volts on our test bench - there's some scope images on our website here: http://trigger-wheels.com/store/contents/en-uk/d25.html BTW should you need it we stock the "proper", military spec shielded wire.

mark pietz · Post by **mark pietz** » Sun Dec 02, 2012 1:40 am

Shielded security alarm wire from Home Depot works fine. Something like 24 cents/foot.

Dean924s · Post by **Dean924s** » Sun Dec 02, 2012 8:51 pm

Well 4 years and more than 100K miles on the radio shack wire with no issues seems to tell me that it works pritty well. I got a 50' roll for somthing like $9.99 4 years back when I installed it on my car.

thesameguy · Post by **thesameguy** » Fri Jan 18, 2013 12:29 am

You can buy the stuff from McMaster-Carr, part number 8219K61.

Use with controls and instrumentation where high-temperature protection is required. The conductors are stranded silver-plated copper with PTFE insulation, a braided silver-plated copper jacket, and a PTFE outer jacket. Conductors are color coded (1-black, 2-white, 3-red, 4-green). Temperature range is -67° to +392° F. Meets MIL-W-16878/4.

Note: Amp rating is the max. value for a single conductor at a room temperature of 86° F. Amp rating decreases as room temperature increases, if multiple conductors are bundled, or if conductors are inserted into conduit.

8219K61 is:

392 Degree F Multiconductor Cable 18/2 AWG, .18" OD, 600 VAC, White

It's $4/ft. Should be near-indestructible.

If you want to roll your own, Mouser #517-1170-50/18 is 3M 1170 aluminum foil 1/2" x 36yd EMI shielding, which is similar if not identical to what Ford uses on their VR sensor wiring. It has an acrylic adhesive so it'll stay wrapped around whatever you wrap with it.

It's $26/roll.

I went with used wiring. The mid '90s Explorer/Ranger (with the square front end) yield an EDIS-6 module, and it's pretty painless to get the connector and several feet of wiring. It snakes along the passenger side fender and under the brake booster. The oval-body Tauruses with the OHV V6 have the VR sensor right on top, passenger side, so you can grab the sensor, the connector, and another 2' of wiring. It loops around the top of the engine and heads into the firewall - also very easy to get.

When you're done, you have about 5' of shielded wire with matching grey/blue wires, an EDIS connector, and a VR connector. In my case, since I had a 3' long EDIS pigtail I had enough wire to get the PIP/SAW into the cabin & the MJ controller, too. With the exception of the rev limited->coilpack wire, it's basically all factory Ford wiring.