Coolant gauge issue

SouthArk370Z

Please get some help before you kill some electrical component(s) or start a fire.

But, yes, a decent multimeter and tools to access the wiring/sensors should be all you need. I'm guessing that the problem will be pretty obvious with a visual inspection.

I haven't looked at the wiring diagrams but the 5V reference that Jhill refers to may be internal to the ECM. If so, you will need to check it at the ECM (if possible). If the outputs from the sensors are out of spec (I'm betting that will be the case), the reference is probably not the problem. The 5V ref is just a possibility. I think (and it seems that JHill agrees) that the wiring/sensors is the most likely culprit.

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Jhill

You're pretty safe to check it as the ECM typically have their own resistor in series before the output and that is how they determine a dead short or open as the sensors operating is typically .7-4.5 so if it sees 0 or 5 it know there is an open or short. On sensors that have a sig return it's a little different and if you screw the ref up well like the saying goes garbage in garbage out. Before you even venture in this journey I would highly recommend you pull those codes and get the wiring diagrams that go with those systems. Without proper documentation you are just guessing.

SouthArk370Z

IF the person using the meter knows what they are doing. Even if the ECM is bullet-proof, I'd hate to muck around, short some wires, and put 12V where it doesn't belong (like inside the gas tank). If it were you doing it, I wouldn't be too concerned - I'm not sure OP has acquired the skills to do the job safely.

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Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub
Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

Jhill

Too true. I've seen so called master techs do **** that I still shake my head at. It can be scary out there.

Wilson2608

Both of you are obviously very knowledable about cars/ electrical work, and i basically know little to none about this kind of stuff. But im adament about doing the work myself for the purpose of becoming more educated. When my engine blew in my 300zx I took it upon myself to do a motor swap. It took me like 2-3 months, but eventually i got it perfect with no issues at all. And now i could do it in half that time, and thats the reason I want to fix this issue too. I will follow the procesdure in the FSM so I don't mess anything up and i'll let you guys know!

Thanks so much for help mates

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Stillen G3, z1 Intake Manifold, Stillen Headers, Z1 HFC's, Stillen Catback. 330whp 267 ft- lbs tuned at Z1 motorsports.

Jhill

Dumb ? What's this FSM everyone is referring to? Are you guys getting access to the wiring diagrams?

SouthArk370Z

Factory Service Manual. See link in my sig. Merry Christmas. The wire color codes are not always intuitive.

__________________
Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub
Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

Jhill

Awesome, I can't download it on my phone but I will be once I get to my PC. My biggest worry about buying my z was getting future info if I have to work on it since I was an an ex tech I don't trust a lot of techs out there as there are a ton of bad ones and not being in the field any longer I don't have access to all data. So now I have my source. Thanks.