the sensor has been removed from the radiator and been welded shut, now the coolant light stays on all the time I didn't remove the sensor I got the car like that.

iv read around that people ground the wire from the coolant level sensor wire form harness and it switches the dash light off,
iv also read around that its a brown wire but I cant find it, theres a wire that has been cut real short on one of the harness connectors on the passenger side but not sure if its the right one.

where does the wire come from?

car is a 1980 1st gen.

 

It is a brown wire and comes from the drivers side headlight bundle of the harness. It's wrapped as a separate strand in most cases and will have a bullet connector (female) in the end. The coolant sensor is one lead and should read 'full' if you ground the brown wire to chassis.

 

Illustration: Coolant Level Sensor Wire

 

thanks for the pic.
so its tucked away somewhere behind the battery?

ill have a look shortly and let yous know how I go.

 

i found it, it was separately wrapped but has 3 female bullet connectors at the end,
2 short wires that are orange and brown and a longer wire wich is brown as well but it has the male bullet connector still connected.
are those other 2 shorter wires used for something else?

all 3 wires reach where the sensor use to be,
do i have to ground all 3 wires or just the longest one with the connector still in it?

 

the shorter wire is brown and white... the longer one is full brown and is the one im after.

does the coolant light have a buzzer with it? maybe that's what the extra connectors are for?

where are good spots to ground without drilling holes in the body?

 

Make a short piece of wire (6 inches, 12 or 14 gauge) with a loop connector or lug on one end and a female bullet connector on the other. Connect it to the screw that holds the oscillator right behind the battery (little black box).

I think it's time you download the wiring schematic and start familiarizing yourself with what is going on with this wiring. No better time to learn.

Foxed.ca - Mazda RX-7 Manuals

 

its all fixed now.


did pretty much what you said when I looked at it, just got some wire, crimped it in the female connector on the brown wire then on the other end put a ground connector and grounded it on 1 of the coil pack mount bolts doesn't look very tidy but its just for now anyways when I get a new radiator ill hook the sensor back up I think.


I hate wiring lol but I might start having a look at the manuals, I wouldn't mind tidying some of the wiring up
is the wiring pretty much the same from LHD to RHD just the other way round?

 

Yes, put the sensor back in and hook it up. Verify it works.
The one sure way to kill a rotary is to overheat it.
I know this for a fact from personal experience.

 

I know that, but the car isn't been driven, still have to get it registered.

cant put the sensor back in id have to break the weld on the radiator
I want to change the radiator once its registered anyways then ill wire a new sensor in.

 

I had this problem and I replaced the coolant level sensor with a new OEM one. That seemed to solve it.