More wiring, this time the car side.
I wanted to find a good source of switched +12V and ground, which required probing around the connectors floating in the dash.
I got sick of trying to stab a too-big-probe into the connectors to check for voltage while trying to hold the other probe on a ground and hold the meter and the connector and dropping everything etc etc.
So I bought a cheap small multimeter and a "probe kit" of different probe tips. So I slapped on an alligator clip and a reeeeaally pointy probe. Clamped the alligator on a ground and easily poked the pins. Much better. Highly recommended.
I found the wires that went to the cigarette lighter and little light next to it- Jackpot!
So I went into the pile of interior bits removed from the car and even found the other side of the connector- double jackpot! I pulled the pins out for the little light, I won't be using that, and now have a nice connector to 20A fused power.
With the number of gauges, and hopefully a datalogger, to go in the car, I wanted to make a nice access point for ground and power, so I found these marine lugs the accept 1/4" ring terminals. They don't have caps, but will be back in the dash, so I'm not too worried. Plus, it's fused in case something goes too awry.
Here's the newfound connector and the lugs.
I clipped and spliced to get power to the lugs from the connector. I doubled up the 20awg wire because that's the only size I have, and it seemed like the right thing to do.
I found some nice holes to mount the lugs to in the car. At some point, I had the foresight to buy a kit of stainless hex screws with washers and nuts. It was eyebrow-raisingly cheap on Amazon, so I probably wouldn't trust my life to these, but it was nice to have fresh hardware to pop this stuff in.
Now I can easily add items that need power and ground in this dash area. Yay.
I had to run new wire for the EGT sensor and the oil temp sensor, but the splice had to be near the firewall by the pedals. Horrible contortions ensued to get this stuff spliced in nicely.
I've since learned from RYEPhil that the EGT sensor is probably a K-type thermocouple that needs special wire and connectors to work properly. Thermocouples work by generating a voltage from different materials as they are exposed to heat. When you splice in the wrong type of wire, it jacks with the relationship and pretty much ruins it.
So that's annoying to find out after-the-fact.
Anyhow, I got everything wired up to the other side of the DTM connector and plugged everything in to see if I got it right.
Here's an 11-second video of the gauges lighting up and doing the apparently-desirable needle sweep:
Well, the boost gauge needle doesn't move at all, the oil pressure seems like it might be correct, and the EGT just acted bizarre, which i now know is probably due to my ham-fisted sabotage.
I was grumpy and didn't take any photos. I spent some time double checking things, and that's when Nik told me the boost gauge wasn't working even before the flood. I probed the signal output of the boost sensor and there was nothing there. Due to the fact the gauge fired up and behaved normally otherwise makes me think the sensor is bad.
I hit up RYEPhil for a sensor recommendation and he pointed me to some $200+ MoTec 3bar 5V reference sensors that "might be acceptable". I paid $1500 for the car.
In a fit of cheapness and not being fully committed to this solution right now, I instead found a $17, yes $17, boost sensor WITH GAUGE. RYEPhil is not amused by my #1 Lucky Golden Boost Gauge, but it should be here next week and we can all find out together.
Thanks for reading!
damen
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