New (kinda) on ClubRX - cleaning your ignition switch, no-start problems
01-26-08, 08:48 AM
#1
RX-7 Bad Ass
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New (kinda) on ClubRX - cleaning your ignition switch, no-start problems
Hey all -
I had to re-do the page after the site went down a while back, but fortunately I had a copy/paste of the page, so I had less typing. The old link to the page won't work, but this will -
http://www.clubrx.org/default.asp?id...ntent=74&mnu=5
Basically, how to remove and clean your ignition switch. This can be the cause of no-start problems, primarily when you turn the key to Start, get nothing, and on the 3rd try or so the car starts.
This helped my car, but I still had problems. I finally got medieval with a multimeter and did some homework.
The ignition circuit on the FD is VERY simple, as it is on most cars. The starter has a big power wire straight from the battery that's un-fused. That's the wire that bolts on the starter. There's also a small wire that clips on to the starter - that sends the "start" signal to the starter from the key.
When you turn the key to Start, the ignition switch makes contact and sends 12v heading towards the starter. From there, it goes to the clutch switch. The clutch has to be down for the signal to continue. If the clutch switch is bad (and there have been documented cases of them breaking) it will need to be fixed or bypassed. From there, it goes to the starter interrupt relay.
This relay ties into the factory security system - if the security system is going off, this relay is energized, breaking the circuit to the starter and keeping the car from starting. The CPU (not the ECU, the CPU is a black plastic box in the driver's kick panel) controls the security system, and it's what engages or disengages this relay.
In my case, this relay was flaky - it was causing the problem. You can bypass this relay with a jumper wire, or get a new one. The part number is H302-67-740 and it's about $23 or so.
Last part in the chain is the connection to the starter itself. This small clip-on connector frequently gets oil and crap in it, making a not-so-great electrical connection. If you unplug the connector and study it, you can actually disengage the plastic shell of the connector and remove it from the internal metal clip. On the side the wire comes in is a plastic tang - press it down with a thin knife blade or a fine pick, and you can slide the shell right off. I then used a wire wheel on a Dremel to clean the contact up nicely, then popped the shell back on.
Automatic FD's seem to frequently have click-click-start problems. I think part of it is from the starter being "backwards" and subjected to more heat, as well as the starter wiring. Mazda had a TSB for the automatics with hard starting problems that included a revised wiring harness for the small wire going to the starter. Supposedly the heat soaks into the wiring, ups the resistance of the wire, and you get a no-start. Whether that TSB part is still available is unknown. Part number is fdy1-67-sh0, and MazdaPartsCheap.com shows it for $92. This is likely something simple that could be homemade, but as I don't have an automatic, that's out of my field of experimentation
.
Anyhow, hopes this covers some bases. If you do have starting problems, best thing to do is go down the line with a multimeter and see where the problem is.
Dale
I had to re-do the page after the site went down a while back, but fortunately I had a copy/paste of the page, so I had less typing. The old link to the page won't work, but this will -
http://www.clubrx.org/default.asp?id...ntent=74&mnu=5
Basically, how to remove and clean your ignition switch. This can be the cause of no-start problems, primarily when you turn the key to Start, get nothing, and on the 3rd try or so the car starts.
This helped my car, but I still had problems. I finally got medieval with a multimeter and did some homework.
The ignition circuit on the FD is VERY simple, as it is on most cars. The starter has a big power wire straight from the battery that's un-fused. That's the wire that bolts on the starter. There's also a small wire that clips on to the starter - that sends the "start" signal to the starter from the key.
When you turn the key to Start, the ignition switch makes contact and sends 12v heading towards the starter. From there, it goes to the clutch switch. The clutch has to be down for the signal to continue. If the clutch switch is bad (and there have been documented cases of them breaking) it will need to be fixed or bypassed. From there, it goes to the starter interrupt relay.
This relay ties into the factory security system - if the security system is going off, this relay is energized, breaking the circuit to the starter and keeping the car from starting. The CPU (not the ECU, the CPU is a black plastic box in the driver's kick panel) controls the security system, and it's what engages or disengages this relay.
In my case, this relay was flaky - it was causing the problem. You can bypass this relay with a jumper wire, or get a new one. The part number is H302-67-740 and it's about $23 or so.
Last part in the chain is the connection to the starter itself. This small clip-on connector frequently gets oil and crap in it, making a not-so-great electrical connection. If you unplug the connector and study it, you can actually disengage the plastic shell of the connector and remove it from the internal metal clip. On the side the wire comes in is a plastic tang - press it down with a thin knife blade or a fine pick, and you can slide the shell right off. I then used a wire wheel on a Dremel to clean the contact up nicely, then popped the shell back on.
Automatic FD's seem to frequently have click-click-start problems. I think part of it is from the starter being "backwards" and subjected to more heat, as well as the starter wiring. Mazda had a TSB for the automatics with hard starting problems that included a revised wiring harness for the small wire going to the starter. Supposedly the heat soaks into the wiring, ups the resistance of the wire, and you get a no-start. Whether that TSB part is still available is unknown. Part number is fdy1-67-sh0, and MazdaPartsCheap.com shows it for $92. This is likely something simple that could be homemade, but as I don't have an automatic, that's out of my field of experimentation
.Anyhow, hopes this covers some bases. If you do have starting problems, best thing to do is go down the line with a multimeter and see where the problem is.
Dale
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box-o-aces (07-13-19)
01-27-08, 03:52 PM
#2
RX-7 Bad Ass
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Dang, no replies? People have been bugging me to get this writeup back in there!
Dale
People have been bugging me to get this writeup back in there! Dale
03-06-08, 07:11 PM
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Hey, I had a similar problem but it ended up being my clutch switch. I replaced the spring in the clutch switch with a similar size spring out of a pen. Important note about the cleaning procedure: When you get the ignition switch out, don't try to remove the black part that has the springs in it. I tried this and i had ball bearings bouncing all over my garage. Luckily I found them.
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03-07-08, 10:03 AM
#9
Gone to the dark side
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Great Write up! Thanks Dale.
This has plagued me for so long that I installed and push button start in my car.
We all at one time or another will go through this, thank you.
This has plagued me for so long that I installed and push button start in my car.
We all at one time or another will go through this, thank you.
03-09-08, 12:42 AM
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I had this issue with both of my Rx-7's and I ended up bypassing that switch entirely and making a "start button" for the starter. So it was essentially the same system as an S2K, you had to have the key in with accessory power and then you just pressed the make shift button for the starter.
It was a very easy process.
It was a very easy process.
03-22-08, 09:46 AM
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05-01-08, 01:32 PM
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