Hey guys,

I own a 01' FD RX7,

I have been trying to troubleshoot my failed/dead speedometer and odometer not counting problem,

as far as I have gotten is taking the cluster apart for suspect capacitors (as seen in another thread)...

I have also cleaned each plug behind the cluster and checked most of the wiring behind the dash and the engine bay...

I was wondering if the transducer/speed sensor is a usual fault for this, and if so, where about is it located on the gearbox??

My car is modified and lowered so I find it hard to see most of the gearbox and wiring..

Thanks in advance

Jim

 

The Speedometer sensor is on the transmission tailhousing on the passenger side (Driver's side for RHD ones), held in by one M6 bolt. Here's a pic of it: MAZDA RX7 FD SPEEDO DRIVE SPEED SENSOR - JIMMY'S | eBay

When you pull the sender, hook a meter up to it and check to see that it puts out EIGHT pulses when you turn it over ONCE. If it does, the sender is good. Also check the drive & driven gear for chipped teeth, spinning on the shaft(s), etc.

 

Does your odometer light up and display the mileage?

 

Thanks. I'll have a look at it
When you say pulses. Do you mean hook it into a oscilloscope or is the ac function on a voltmeter sufficient.

It still shows the milage on the screen. They're all 00000 now because I bumped the reset.

 

If i were to guess, you would check it with OHMs, nothing on a car is AC, you either check things with OHMs, or DC

 

Checking for continuity would be the first thing, but I suspect its output is an AC Sine Wave like the T-56. An oscilloscope isn't really necessary for this as long as you turn the sender gear slowly. 1/4 turn should make a regular multimeter jump twice

 

alright I will give it a go.

Thank !!