JimsNovaLS

I'm installing a gen4 where a gen3 was and got a Casper's cam sensor extension harness. With all the talk about having to switch the outer two wires in an extension harness, I'm not sure if mine is made correctly or not. I don't want to fry my new sensor by having it wired incorrectly.

My harness has brown-pink-red in cavities A-B-C on the back (harness) connector and red-pink-brown in A-B-C on the front (sensor) connector.

The red wire in the extension harness plugs into red wires at the back and at the front where it plugs into the GM short harness on the new timing cover so it seems like it's manufactured correctly, no? I'm about ready to start this think so please help!

JimsNovaLS

No one knows???

stevieturbo

You will not damage the sensor through incorrect wiring.

JimsNovaLS

Thanks for replying Stevie. Others, in other threads, have said it would fry the sensor. How would I know if it's backwards? When no one replied, I just plugged it in the way it came and took a chance. It runs but seems real rich, going to tuner tomorrow. It's setting P0103 and P0200, but nothing about cam sensor. My scanner doesn't read cam signal so I don't know.

tech@WS6store

iTrader: (2)

If it didnt work it would have a VERY hard time starting. It may or may not throw a cam code or cam/crank correlation code.

big hammer

It'll start without the cam sensor. Just crank longer.

Running rich has nothing to do with it.

I went through this on my car. I don't remember the exact order but you can figure it out for yourself.

The harness plugging into the sensor still have a positive, a ground and a signal. If you look inside of the sensor plug it'll tell you which is which. I think the middle is supposed to be ground, but I can't remember 100%.

If this is an fbody and the tach is working then your cam sensor is fine.

My harness was wired backwards and it did roast the sensor.

stevieturbo

Simple test, even if you dont want to connect it to the car.

Get a PP9 9v battery and multimeter. There are only 3 pins, so wont take long to test all configurations.

Basically the output wire of the sensor will switch between lo/hi voltage ( usually 5v output but can depend on input voltage...but often still 5v even if input voltage is higher ) when a ferrous metal object is in front of the sensor. ie steel

When you get the right pinout you'll see this happen.

If you dont or cannot remove the sensor from the car, you'll need to crank the engine over to see this, but with a multimeter and the speed this may be happening, it may be less obvious unless you turn the engine over by hand.

If you search youtube, there will be various videos that will show test methods etc although usually testing is done with a scope. But for this you can get away with a digital multimeter set to say 12v DC

JimsNovaLS

Thanks guys. Had the car to the tuner and he said the cam signal was working correctly. Some harnesses must come with the outer two wires backwards and some, like mine, are correct. Mine wound up with the red wire plugging into red at both ends, if that helps anyone else before hooking theirs up.

stevieturbo

The front and rear cam sensors seem to use different pinouts respectively.

big hammer

Yes they do and that's the issue