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-   -   No ignition problem (https://www.miataturbo.net/general-miata-chat-9/no-ignition-problem-12946/)

piratetim 09-28-2007 02:10 AM

No ignition problem
 
Ok so im replacing all of my parts and im almost done. I put the key in and turned it and there was nothing but the door open chime. I check my fusible link for ignition and it was blown. So I replaced it. Now I turn the key and have accessory power but thats it. SO the radio will turn on but no dash lights, fuel pump hum, ignition power at all.

any ideas?

piratetim 09-28-2007 01:13 PM

no one?

Joe Perez 09-28-2007 01:16 PM

Er, yeah. You've got an open-circuit somewhere. No real shortcuts on something like this- just gotta start searching.

This may help: http://www.madracki.com/miata/images...g/2000wire.pdf

piratetim 09-28-2007 01:41 PM

im so bad with electrical i can barely read this thing. Im guessing im looking for a ground...?

Mimime 09-28-2007 01:56 PM

have you checked your MAIN relay? is it making any sound.. try holding it down while u start you car.

Mimime 09-28-2007 01:59 PM

have you checked your MAIN relay? is it making any sound when you try to start the car? TRY holding it down and turn the key! It could be hard for LHD cars... keke

piratetim 09-28-2007 02:10 PM

theres no clicking or anything. No lights at all come on the dash. But the radio comes on lol. The interior light also has power.

piratetim 09-28-2007 02:11 PM

wait..you want me to press down on the MAIN relay under the hood and have someone try to start it?

Mimime 09-28-2007 02:33 PM

Yes..! I am not sure what year you have, but mine its 15 years old.. the MAIN Reply legs will wear out because of heat. Might want to see if the RELAY are in good condition. Try pressing on the MAIN RELAY and see if u could start it up.

Joe Perez 09-28-2007 04:30 PM

Ok. Simple tests assuming you have a multimeter.

Check the 15A "engine" fuse, in the fusebox next to the driver's left leg. If it's ok, then with the key on, check to see that you have voltage at the black/white wire at each of the two ignition coils (terminal A). If that's ok, then everything on the control side of the main relay is ok.

Check the 30A "fuel inj" fuse, in the under-hood fusebox. This is what supplies the power to the switched side of the main relay. If it's ok, then with the key on, check the large white/red wire at position 1B on the ECU. (W/R can also be accessed at the VICS valve, EGR valve pin C & D, the Cam sensor pin A and Crank sensor pin A, and the MAF sensor pin C)

Assuming that the fuses you checked are ok, then:
1- If you have power at B/W on the ignition coil, but not at W/R on the ECU, then the main relay or its associated wiring is probably bad. (Its ground is behind the passenger's side headlight)
2- If you do have power at W/R on the ECU, then the main relay is fine.

piratetim 09-28-2007 04:41 PM

ok, thanks for simplifying that for me. Ill try that tonight when I get home from work and let you know what happened. Thanks agaiin

Joe Perez 09-28-2007 04:47 PM

You didn't indicate whether the starter itself is turning when you turn the key to "start."

The starter circuit is independent of the main relay. If the starter is *not* working, then figure that out first.

piratetim 09-28-2007 05:01 PM

starter isnt working either. Like I said there is absolutely nothing if I turn the key other than accesory and the dinging from the door being open. So the radio is on but there is no fuel pump noise..no lights on the dash...no clicking. If I turn the key all the way forward nothnig changes and there is still no noises...evn the starter. There is absolutely nothing.

Joe Perez 09-28-2007 06:01 PM

In that case, forget about the Main Relay for the moment, and go after the starter instead. It's a simpler circuit, and may lead you in the direction of the solution to the other problem as well.

On the PDF I linked to, go to page 19 (diagram A).

The Battery + terminal goes to the starter. Then it goes through the 80A main fuse. From there it splits. One wire goes to the big terminal on the alternator. The other to the 40A IG KEY fuse, and then to the ignition switch.

Since you have working ACC power, it stands to reason that to this point everything is working. What's puzzling however is that there is very little between this point and the starter. So it might still bear double-checking these points.

The heavy white/blue wire leaving the keyswitch goes through the clutch interlock switch (the big white one at the bottom of the clutch pedal's travel) and then the heavy blue/red wire goes from the clutch interlock switch to the starter solenoid. That's about it.

So run through that circuit. Disconnect the wires from the clutch interlock switch and see that there is juice at the white/blue wire when the key is turned to start. Check across the switch for continuity when depressed. Replace the connector and check for voltage at the blue/red wire on the starter when the key is turned to Start and the clutch pedal is depressed.

If all of those conditions are met, the starter should turn.

As an aside, I suppose it bears mentioning that the condition of the battery should be examined. Make sure it's delivering at least 12V when the key is in the Run and Start positions.

piratetim 09-28-2007 06:05 PM

awesome. I like how you manage to put everyhting into an easy to read version. I suggest you writing your own haynes manual....Id buy it haha. So ill try all of this when I get home and hopefully I will have some success. Thank you again.

Joe Perez 09-28-2007 06:18 PM

You know, you are the second person this week to recommend that I write a book. Somehow I just don't see it happening...

However it does pain me to see people having trouble with the electrical system. I realize that for many it's intimidating, but I honestly find it one of the simpler systems on the car in terms of troubleshooting and understanding how it works. Things like gearbox synchros and Torsen diffs, by comparison, puzzle me. :D

Incidentally, how bad was the fire? I never did see pictures. I'm wondering specifically how much cutting and splicing had to be done to the wiring harnesses, and whether open circuits or shorts may still exist inside the bundles. Because honestly, if you have ACC power then the starter should be working.

piratetim 09-28-2007 06:38 PM

the fire really wasnt that bad. I have to replace my oil return and feed line, a coolant hose, brake master, a vacuum line, NB and WB sensor, ignition wires and plugs. Then figure out the hood. The temp sensor melted a little along with the MAF connector. ( I dont have a MAF anymore) One piece of wiring im worried about is the the shrouding got melted a little to the wire harness that goes behind and then below my coil pack. Im not sure what it is but it is a bit disfigured.

piratetim 09-28-2007 06:39 PM

Keep in mind the fire was all on the left side of the motor and not right up against the block. Mainly the brake cylinder.

piratetim 09-28-2007 06:41 PM

Not having my ignition wires plugged in wouldnt make a circuit uncomplete would it? I feel kinda dumb asking that but wasnt sure if the wires completed a circuit that was needed. B/c currently the new ones are sitting in a box.

Joe Perez 09-28-2007 08:19 PM


Originally Posted by piratetim (Post 157539)
Not having my ignition wires plugged in wouldnt make a circuit uncomplete would it?

It is possible that running the engine (or attempting to crank it) without one or more spark plug wires connected can cause damage to the coils, however this would not cause the problems you are having currently. The plug wires are on the secondary side of the ignition coils, and they are isolated from the main wiring of the car.

I always disconnect my igniter (or on a 1.8, the coils themselves) whenever I intend to crank the engine with the plug wires disconnected, such as while doing a compression test. It does not prevent any other part of the car from working (although it may throw a CEL, no big deal)

In fact, just disconnect your coils right now and keep them disconnected until you've got the starter turning and the rest of the systems (lights, fuel, etc) doing their thing. Maybe disconnect the injectors too.

One of the first things you mentioned was that the "fusible link for ignition" was fried. I assume by this you mean either the oversized 40A "IG KEY" or 80A "MAIN" fuse under the hood? Consider this- something caused it to blow. Probably a short circuit due to a melted wire.

Still- focus on the starter first. That's the simplest circuit, and the one nearest the top of the chain.


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