It may depend on the application. But the DIS brick that I have (from a 3100 SFI) uses pins A and C for the crank trigger. According to the schematics, Pin B is an optional (unused) ground, for RFI shielding on the crank trigger wires.
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11:05 PM
Apr 7th, 2012
ConvictedRedneck Member
Posts: 1034 From: Easton, PA - USA Registered: Nov 2005
I'm curious to this as well...I'll be doing this as soon as I get your connectors, phonedawgz. Did the two different wiring setups use the same sensor? I'd assume they did but just throwing out ideas.
I think the first time I wire it up I'll use A-C. Ryan has that in his wiring chart. However, this chart still has it A-B...
The reason I asked about the sensor type is because the picture above is specifically for using the ford escort sensor per that thread, whereas most other guys are using the GM sensor meant for the 3.4 block.
On a related note, my Ford crank sensor isn't labeled A/B, does it matter which wire goes to which pin on the ignition module?
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12:09 PM
Blacktree Member
Posts: 20770 From: Central Florida Registered: Dec 2001
Since I'm putting DIS on a 2.8, there are no provisions for a GM crank sensor like on a 3.4 (or that's what I was under the impression of). I followed the instructions as outlined here and the design of the ford sensor makes it ideal to use in that application.
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07:23 PM
Blacktree Member
Posts: 20770 From: Central Florida Registered: Dec 2001
It is my understanding that it does matter if the crank sensor is wired backwards. The page below is quite long but if you scroll down to where it says:
The following diagram shows what happens when the VR jumpers on the V3.0 PCB or the VR sensor is wired incorrectly:
Then you'll see the explanation of what can happen if the sensor is hooked up incorrectly. That's a missing tooth system instead of a extra tooth system but you can see how things get messed up.
I'm kinda stuck...the thread I referenced for adapting the 2.8 to DIS using the Ford sensor doesn't mention which pin is which on the sensor and the one I have doesn't have any labeling...
Any way to determine this? Trial and error?
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07:38 PM
ConvictedRedneck Member
Posts: 1034 From: Easton, PA - USA Registered: Nov 2005
As you are wiring up the VR sensor make sure you have the polarity correct. The following procedure is on the 'net at several locations and works well:
Connect the sensor to a digital volt meter and place the meter on the most sensitive DC voltage setting.
Take the sensor and allow it to drop onto a steel object while viewing the meter.
The meter will momentarily register a small voltage (less than 100mv). If the voltage is positive then the (+) lead on your meter is connected to the VR sensor (+) pin. If the voltage is negative then you have your meter probes switched around.
The sensor should produce a positive voltage spike as it transitions from air to metal. Dropping it onto a steel plate is an easy way to do this.
Keep up the great work on this.
- Steve
So assuming I can figure out which pins are positive/negative on the sensor, anyone know how positive/negative corresponds to the wiring at the DIS module?
ETA: Adding to this, would the positive pin be the 'crank sensor hi' or 'crank sensor low' as labeled in Ryan's wiring chart? I'm inclined to think positive would be 'low' since the low spot in the harmonic balancer is what sensor first picks up and the 'hi' follows the low spot, making it the negative?
...I'm by no means an electrical engineer so this is looking at it from a very mechanical, intuitive perspective.
[This message has been edited by ConvictedRedneck (edited 04-10-2012).]
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07:46 PM
Apr 11th, 2012
neophile_17 Member
Posts: 58 From: Southington, CT Registered: Aug 2007
You're putting too much thought into it. The electrical guys think of high as positive. Even if you get it backwards you shouldn't cause any damage. I didn't anyway.
~sam
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09:43 AM
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phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
