Holy shit I love your setup. I'm just electrical ignorant, I despise it. So by taking out the oil sending switch and using the new one for the gauge, will it throw a low oil light? If its just the gauge that won't move I won't care tbh
Thanks
So I re-read what I had typed, along with your question, and realized I probably wasn't very clear. Sorry about that :-/
There are two oil related senders on your car (assuming we are talking about a 95 Mustang with a 5.0). One is for
oil level, and is located on the driver side of your oil pan (the rear sump portion). The other is for
oil pressure, and is located on the driver side of the block, close to where the oil filter goes. (This is not like the coolant temp, as there two coolant temp senders on the car, that perform an identical function: one for the gauge, and one for the ECU.)
The gauge in your cluster hooks up to the
oil pressure sender. The warning light in your cluster for low
oil level hooks up to the low oil level sender. Neither of these connect to the ECU.
For the
oil pressure, if you want to put in an aftermarket gauge, you can completely replace the stock oil pressure sender with the one that came with your gauge. This will not affect the car (other than making the oil pressure gauge in your dash no longer work - which is fine, it's not very accurate anyway).
There's no reason to replace the
oil level sending unit in the oil pan unless it is faulty. If it is faulty, replace with a stock/OEM replacement.
If you swapped out your oil pressure gauge, and are getting a low
oil level light, you either replaced the wrong sender, OR your stock oil level sender happens to be faulty (or you have no oil in the car, which is a possibility).
Edit: also, I have completely re-wired the dash (and some other stuff), if you have any electrical questions on that as well, I'd be happy to assist.