I'm working on my car right now and trying to fix the starting issue. All the dash lights come on but it doesn't crank. I recently changed the starter motor from my spare engine so I don't think that's the problem.

Being a noob I removed both interlock (white) and clutch (silver) switches. Interlock was a pita to remove and I bet it'll be pita to install. Just to make sure I made a perfect noob job I also snapped off the clutch switch (silver) cable, it kind of broke easy so I don't know maybe that was the problem in the first place.

So my question is do I bypass the silver or the white one? Can I bypass both? What do I do?

Btw easy on the noob, it's freezing cold outside and difficult to do all this with a lousy mobile phone led light. I've quickly searched some thread but so much talk of clucth and interlock switch I dont know which one does what.

 

Ok, I'm bypassing the cables going into the silver switch and putting white interlock switch back to how it was, fingers crossed.....

 

I don't know what the interlock switch is for, because I don't think I used it in my AT to MT swap, but you can bypass the clutch switch. It consistently starts better, but the problem is that you can start your car without having the clutch in.

 

For me that's a good thing. This is my first car that I have to press the clutch in to start and I think it's not necessary. Only my motorbike had the clutch in thing and that also failed from time to time due to water and dirt getting in. I think it's more for American market where majority have a 2nd car or used to driving an auto. I have never owned anything but manual.

I ordered Pettit Starter Booster which should also help with starting problems, I will also buy a Bosch or Varta battery (normal size, and higher power if possible), was thinking of something like odyssey 925 but decided reliability comes before weightloss.

I would like to find out what interlock switch actually does cause I'd like to eliminate or bypass it while I'm already dealing with clutch area. One less thing to worry about.

 

One of the clutch switches is in the starter circuit, I think that's the bigger one in your pic. It simply interrupts the starter signal. A simple jumper wire solves that problem.

The other switch gives input on the clutch pedal's position to the ECU as well as the cruise control. If you push in the clutch when cruise is on, it cuts the cruise control. The ECU uses the clutch switch to determine if the engine is loaded by the transmission spinning. Without the clutch switch you can get a funky idle with the stock ECU. Sometimes it will have idle surge, etc.

Also, the small switch acts as a stop for the clutch pedal's travel. That's why it's threaded, you can adjust the stop point of the pedal.

Dale

 

jumper the interlock switch temporarily to see if it's the problem. if it isn't, put it back.

 

I bypassed the interlock switch and clutch switch but no luck I bypassed just the clutch switch still no luck

Looks like the car will have it's first ride on a tow truck to the mechanics.

When I first had this full power but no crank/start problem, I tried to jumpstart the car then I changed the starter motor. Now I bypassed the clutch switch. So now I'm thinking it can be alarm system related (previous owner fitted one, I'll probably remove it) or fouled spark plugs cause the engine got flooded recently but I think that's a slim chance since the car did not start once before the engine was flooded.

 

If it was your spark plugs, the car would at least turn over.. look into that alarm system thing.

 

This has come up many times in the past. Your problem is the starter cut relay, located behind the driver's kick panel. There are two fat wires going to it, a Black/blue and a Blue/white. Connect those wires with a jumper wire of the same gauge and you'll be good to go. Either that or buy a new relay.

 

Thanks, you probably saved me from a tow truck cost I'll try this as soon as the rain goes away, sucks not to have a lock up garage

Thanks, I thought the silver smaller is the one to jumper and the white bigger one (interlock) is the one ppl are not sure about but I will jumper the bigger (white/interlock) one in the pic and reconnect the small switch (silver one) back to how it was.

But I ripped the cable of the clutch position switch (silver) when I was trying to remove the switch (I'll fix it). I don't think my car has cruise control (no buttons on steering wheel). Sooner or later I want to buy PFC and go single turbo, for future reference, does removing this clutch position switch or jumpering it's cable cause funky idle and idle surge on stock ECU only or will it cause problems with PFC also?

...and thanks all for the help.

 

This was the problem with my car. The funny thing was that I fought a 'starter' problem two years ago. Coincidentally, the starter had a glitch of its own, but this past summer I could hear clicking while driving. I replaced the relay with a used one which laster a couple of months. You gotta hand it to the Japanese. They make things pretty consistent. I've had this same discussion with so many people this past summer. This relay seems to have reached the end of its life on many FDs lately. Just bypass the stupid thing. It's part of the useless security system. Make yourself a jumper with a 12 gauge wire or whatever the OE wire is and crimp two high quality spade connectors. Jumper the two wires I mentioned above and Voila!

 

Wow man, thank a lot, I also hear clicking sometimes when driving and the sound comes from around the kickpanel, clutch switch area, I mentioned this in click click start problem thread but obviously what you mentioned here is the problem.

I will jumper it straight away, not going to buy a new one. The less things that can go wrong the better.

So I will jumper the white clutch interlock switch, I will bypass the starter relay, remove the alarm, and if I can find out I'll bypass the auto door lock thing and anythingelse that can go wrong in the future.

 

Good call on most of them. I'd leave the clutch interlock switch in there in the event that someone else jumps in to start it and plows into something...just my $0.02

 

Just before I bypass the starter relay tomorrow, I've spoken with a mate of mine today. He an engineer and a M5 owner. He didn't insist or anything and he said he doesn't know much about RX7s but he just suggested that I look into it before I do this mod as bypassing starter relay might cause drained battery problems or even cause fire etc. He was basically saying to be careful with electrical mods. Is this a common mod (jumpering starter relay) amongst RX7 owners?

His suggestion was since I can buy generic relays for cheap, to buy few and change as they fail.

 

You're talking to an engineer with well over 25 years of automotive experience and with over 15 personal RX7s under his belt and many, many, many dozens of serviced vehicles.

It's important to keep in mind that this is a starter CUT relay. It gets activated by the CPU as part of the theft-deterrent system. This is not an integral part of a typical starting system. Its primary purpose is to defeat the starter upon activation not enable it (in other words, when the theft-deterrent system detects a problem, the starter is disabled). This starter cut relay does the exact thing your clutch interlock switch does. The clutch interlock switch is activated mechanically, while the starter cut relay is activated electromechanically by a little coil which receives a signal from the CPU. Your idea to bypass the clutch switch should have the same "risks" as bypassing the starter cut relay. The fat wire which goes through the starter cut relay as well as the clutch interlock switch only receives a signal when you turn the ignition switch. There's no wizardry there, just a dumb direct signal from the ignition switch. The starter cut relay determines if a signal should go to the clutch interlock switch and the clutch interlock switch determines if a signal will go to the starter.

Don't misunderstand, I'm not saying this to sound like a know-it-all, but in this particular case, I think you need to think logically about the situation. If you're not comfortable, buy a relay from Mazda because you can't use an aftermarket relay unless you make a few changes - an then you're dealing with mods again. My advice is purely from an analytical and logical viewpoint and not to convince you to take on something on that you feel is risky.

 

Like I said my mate did not insist or claim that he was 100% sure, his was just a friendly suggestion to check further and since your final explanation it's even more clear. It was never my intention to make it sound like my mate vs. you or doubt your knowledge and I hope you didn't misunderstand. I just wanted to raise the question before I pulled the plug.

Anyway, I bypassed the clutch interlock switch and the starter relay and fixed the ripped cable of clutch switch today. It's perfect! I'm very happy and really appreciate your help. I also had the alarm system checked and everything is good, no lose wires, no wrong connections or nothing that'll drain the battery abnormally.

 

bringing this thread back from the dead because it is 10000000% spot on to my EXCACT situation.

i am in the EXACT same situation. i just want to know if this would also affect the fuel pump. would this issue keep the fuel pump from priming when the key is turned?

 

The answer is no. Your fuel pump should still prime when you turn your ignition to "on" regardless if the clutch switch is in there or not.

When you swapped the motor, the motor came with its own harness right? Happen to know what series FD the harness went too? You might have a series I-III harness on like a series 5 or 6 ecu or vice versa.

 

Hoping this is my problem as well. Going to make a little jumper wire today and hopefully the car will fire!

 

Thanks forum!!

My blue switch gave me starting problems as well. 5mins later, with wires laying around.

Starts!