Car won't started after HC fix

[stamp11127]

In the battery junction box, mini fuse 10 is hot at all times. This protects the secondary side of the fuel pump relay(fpr) which runs the fuel pump. You should have 12v here.
The secondary side of the fpr has two blades were interested in, #30 (pwr feed) and #87 (pwr out). You should have 12v at the connector that #30 plugs into. Most relays have the numbers on the bottom of them next to the blade for you to tell which is which.
With the inertia switch unplugged, remove the fpr, jump #30 to #87(where it plugs in) you should have 12v at the inertia switch plug. If it is less than 12v check the voltage at the top large connector of the three large connectors on the driver side firewall next to the brake booster. This is the only connector between the fpr and the inertia switch connector.
All of this is testing voltage on the DG/YE wire.
If you have 12v at the inertia switch connector the next step is up to you. You can jump the inertia switch by jumping the DG/YE wire to the PK/BK wire. You now are supplying power directly to the fuel pump & can try starting. Pull any of the jumpers to kill the fuel pump.
If you drop down to the 6.8v anywhere on that wire you have a bad connection or high resistance causing the voltage drop.
Since you can run a dvm I'm assuming you know how to make the jumpers. If not I'll give you some step by step instructions, just let me know.

This is from the wiring diagram for a 99. Hopefully they haven't changed anything if yours is a different year.

 

[Gibbers18]

Thank you for the reply stamp, so the plot has only thickened...

I tested the fuse and checked pin #30 and all was good, had 12V. I jumped the relay from #30 to #87 and checked the voltageat the disconnected inertia switch and have 12V, tried starting the car but still nothing.....HOWEVER, two things:

1) When I have a relay in (I have tried a couple with the sam results) I only get 6.88 volts down at the disconnected inertia switch, and

2) I picked a NOID and tested the fuel injector circut, and got NOTHING, so no fuel injection going on as well..........

 

[stamp11127]

Did you also jump the inertia switch? If so you should hear the fuel pump humming right along.

No injector pulse points to the pcm/pats. Here is some info from the service manual:
The PATS uses the PCM to enable or disable the engine. The instrument cluster communicates with the PCM over the SCP network in order to enable engine operation. The instrument cluster and the PCM use sophisticated messages in order to prevent a theft. The instrument cluster and the PCM share security data (when first installed together) that makes them a matched pair. After this security data sharing, these modules will not function in other vehicles. The shared PCM ID is remembered even if the battery is disconnected. The instrument cluster also stores the vehicle's key identification code even if the battery is disconnected. There are special diagnostic procedures outlined in this workshop manual that may be carried out if either a new instrument cluster or PCM needs to be installed.

All elements of PATS must be functional before the engine is allowed to start. If any of the components are not working correctly, the vehicle will not start.

PATS uses a visual theft indicator. This indicator will prove out for three seconds when the ignition switch is turned to RUN or START under normal operation. If there is a PATS problem, this indicator will either flash rapidly or glow steadily (for more than three seconds) when the ignition switch is turned to RUN or START. PATS also "blips" the theft indicator every two seconds at ignition OFF to act as a visual theft deterrent.


What connectors did you disconnect in order to move the dash? Any chance one isn't seated correctly, or missed a ground? Did you disconnect the pcm?

 

[Gibbers18]

Damn PCM....lol. yes I did disconenct about three grounds on the passenger side inside the cab and one in the hood, I will pull them, wire brush them, and reseat them and see if that helps, along with reseating a couple of the connections that had to be disconnected.

Does the PCM have its own independent ground? I don't have the flashing theft light on my dash. I am almost positive I did not disconnect the PCM. Is that that box that sits up and under the dash at the firewall on the driver side? If so then no, I only had to disconnect connections on the passenger side to swing the dash out so I could get at the heater core box....


GOD I will do a LOT of swearing if my new heater core leaks after all this

 

[stamp11127]

The pcm is located over near the battery on both the 4.6 and 5.4. The ground for it is on the passenger side firewall in the engine bay.

Since you had 12v at the inertia switch using the jumper it tells me that portion of the circuit is fine. The 6.88v you read with multiple relays in place may be a fluke. If the circuit isn't energized long enough you may end up with an incorrect reading on the meter if it is auto ranging/reading. If the 6.88v is accurate the only way to drop down is with resistance - which the other test proved doesn't exist - other than in all the relays, I doubt it.

Looks like your main problem has to do with the pcm. One of pcm's many functions is to control the fuel pump relay. I'm starting to wonder if the cluster is connected and communicating with it. If it isn't you'll have your no start condition.

If you turn the ignition to "on" do the gauges self test? How many of the idiot lights don't illuminate, if any?

 

[Gibbers18]

Does the PCM actually sit in the engine compartment, or insdie on the firewall under the passenger side?

When I turn the key on, everything illuminates appropriately as I recall them. No flashing theft light, the check engine light sits on (which I recall it doing), but nothing else out of the blue.

If it will help, I am also talking to a guy on just answer because the car has been down for two weeks and I really need it, so I have attached the link so you can read what he has had me do as well.

Expedition: I recently performed the heater core/blend door - JustAnswer

 

[mazdaparts]

This might be a stupid question/answer, but is the inertia switch tripped?

 

[stamp11127]

I read the just answer stuff....before checking engine sensors, I'd make sure my repair didn't cause the problem. No need to add to your current problem.

Still think your problem is tied with the dash/heater work. If it was running prior to the heater work and isn't now....it is probably with the repair.

"The transceiver module communicates with the encoded ignition key. This module is located behind the steering column shroud and contains an antenna connected to a small electronics module. During each vehicle start sequence, the transceiver module reads the encoded ignition key identification code and sends the data to the instrument cluster. "
Check the antenna...you had to lower the column to move the dash

The PATS transceiver is located to the left of the heater box, may want to check the plug on that. What I have been reading points to testing the cluster if the anti theft does not perform what they call the "prove out".

From the service manual:
Condition:
The anti-theft indicator is never on — no three second theft indicator prove out.
Possible Causes:
Instrument cluster.
Theft indicator

Just for sheets and giggles, you are using the same key that has started it in the past?

When you find it, it will be something stupid and easily overlooked. One of those "I've looked at it for 10 minutes and didn't see it"

 

[braddaddy]

Do u have an alarm system or remote starter? That would turn off fuel?

 

[Gibbers18]

Hey Everybody, thought I would close out this thread by letting you all know the car is running again. Turns out my "helper" did not reconnect a connector that sits under the top of the dash, so obviuously never saw it when looking under the dash....car fired right up. Thank you for all the help, and the encouragement to go back to assuming simplest reason being the culprit!