1989 240sx: Help wiring aftermarket gauges - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Blackhat · 05-17-2007, 09:20 AM

I got several new gauges and I'm having trouble figuring out a couple of things.

1) The water temp gauge works, but shows the temp higher than it actually is. I assume I need to put a resistor in there to change the signal but I'm not sure what size would be needed... Any ideas on how to figure that one out (I'd rather not do trial and error).

2) The Speedo has been one big nightmare. I can't figure out how the oem speedo got it's signal. I have the yel-blu and yel-blk wires, but not sure which is which. I have been assuming the yel-blu is my signal, but I'm stumped on the yel-blk. Maybe ground? or 12v?

3) Fuel level gauge also is a little confusing. I have a Grn-blu, red-blk, and black. I grounded the black and was thinking the grn-blu was just a signal for if the level got too low it'd signal the fuel low light, but apparantly I'm off somewhere in my thinking.

Well, at least the Tacho is working... of course, that one was easy. I'd do more trial and error on this stuff but I'm a little afraid of burning out sensors if I get it wrong.

05-17-2007, 09:20 AM	#1
Blackhat Join Date: Dec 2005 Location: Brunswick, GA Posts: 45 Trader Rating: (0) Feedback Score: 0 reviews	1989 240sx: Help wiring aftermarket gauges I got several new gauges and I'm having trouble figuring out a couple of things. 1) The water temp gauge works, but shows the temp higher than it actually is. I assume I need to put a resistor in there to change the signal but I'm not sure what size would be needed... Any ideas on how to figure that one out (I'd rather not do trial and error). 2) The Speedo has been one big nightmare. I can't figure out how the oem speedo got it's signal. I have the yel-blu and yel-blk wires, but not sure which is which. I have been assuming the yel-blu is my signal, but I'm stumped on the yel-blk. Maybe ground? or 12v? 3) Fuel level gauge also is a little confusing. I have a Grn-blu, red-blk, and black. I grounded the black and was thinking the grn-blu was just a signal for if the level got too low it'd signal the fuel low light, but apparantly I'm off somewhere in my thinking. Well, at least the Tacho is working... of course, that one was easy. I'd do more trial and error on this stuff but I'm a little afraid of burning out sensors if I get it wrong.