I bought three digital guages from a guy here on the forum and began the install in a custom cluster I made. But I have having some questions about the hookup. One is oil pressure; one is water temp; and one is amps. On the water temp do I just connect to the wire on the temp sensor on the side of the block?? As for the oil pressure I got some help earlier from Injuneer and shoebox about the alternate location for the sending unit but here's what else I need to know. Does it require a special sending unit or could it theoretically be connected to the existing oil sending unit at the back of the intake?? I got a sending unit with the guages but the threads don't match up with the hole in the block so I went to Summit and they are sending me a special adapter for it. But maybe I just don't understand how it works. If I thread it into the block and simply hook a wire on the end how can that send the oil pressure to a digital guage?? Sorry for the length but it kind of has me baffled.
Thanks!

 

You can not run two devices (stock gauge + aftermarket gauge) to a single pure resistance type sensor. The coolant temp sensor is a thermistor.... resistance is inversely proportional to temperature. To read that sensor, your stock PCM runs +5V to one side of the sensor, and the other side of the sensor is grounded. The PCM measures the temperature by looking at the voltage on the circuit. Add two gauges to the single sensor, and the voltage vs. resistance calibration is going to be thrown off. Neither gauge will read correctly. That's the same reason you can't tap into the stock oil pressure gauge sensor for your new pressure gauge... neither oil pressure gauge will read correctly.

For the coolant temp gauge, if its electronic, it should have come with a temperature sensor. That sensor has to be located somewhere that it can read coolant temp. There is a hole in the passenger side head (which is really the same hole as the drivers side head, the head is just flipped), with a pipe plug in it. You can put the sensor there, IF you can access it. Its between #6 and #8 and hidden by the exhaust.

If you can't get the temperature sensor in there, I can show you how to insert it in the steam line from the back of the head (I have mine located there).

The electronic oil pressure gauge should have come with a pressure sensor. You screw the adapter that Summit is sending you into the hole right above the oil filter, then screw the sensor into the adapter. Then connect the wire from the gauge to the pressure sensor. The sensor may not fit because it is so crowded, and that's why I showed you the photo of the brass elbow that I used in that location.

 

Thanks, Fred. Great info. If I need to get an elbow for the oil sensor where would I be able to get one or did you make it?? Also, I'll check out the hole on the other side for the coolant temp and see if it is acessable. If not I wil check back with you and see about the steam thing you mentioned.

 

You can get a brass elbow like that at any plumbing store. Just show them the adapter and the pressure sensor, and they will sell you the correct fitting.

This is the extra coolant temp sensor in the steam return line. Notice also that the airbox has two separate IAT sensors, because I feed the data to two separate computers... the stock PCM and an aftermarket MoTeC ECU: