Cougar

Glad you found the heater trouble but it sounds you now may have trouble with the replacement unit.

If the shifter is too loose then I suggest you check that out. It may have gotten disconnected somehow.

I would guess the CTS sensor and circuit is ok. The EGR valve may be clogged up or pehaps the the cold start valve may have a problem.

The "crunching" part doesn't sound good. Things are binding up in the mechanism somehow so you are going to have to remove the door panel and check things. You may have to replace the window regulator.

Since disconnecting the O2 sensor cleared the trouble it seems the sensor is causing a problem somehow at least and it very well may be the load for the O2 heater. The main relay has two contact sections and one is used to provide power to the ECU while the other goes to the O2 sensor and other areas. The power lead for both relay sections is commoned to fuse SBF-2. Perhaps the trouble is with the common power to the relay since that is the only link to the seperate areas. There looks to be an easy way to check the power from fuse SBF-2. Pin 1 of the OBD2 plug is also tied to that fuse so checking the voltage on that pin should be a good easy to get to monitor point. Going over the drawing again I found out there is another power connection to the ECU using the same fuse but it doesn't go through the relay so that may be the memory power to the ECU.

The O2 sensor along with other sensors are tied to power through the main relay so my guess is the sensor is causing a problem to the power for the ECU which uses the same relay.

The trouble may be with the power to the ECU. It could be a faulty ignition relay or main relay if you have one. After looking at some data it shows the main relay is located in the upper far left side of the dash. The relay may be mounted in a brown socket.

It sounds like there is a problem with the wiring to the sensor. Check the voltage on the wire while it's connected to the sensor and then remove it and see if the voltage goes higher. If it stays about the same then the wire has a problem, possibly a shunt to ground.

Considering the age of the car a new radiator sure wouldn't be an unexpected repair job or replacement part.

What you say about the radiator makes sense GD. Hopefully a new one fixes things up. I suspect it will at least.

The only thing I can think of that may be causing the problem other than an intermittent sensor is a faulty headgasket. I suggest you try another sensor and hope that clears the trouble. If it still persists then I think you may have to work on the headgaskets.

Get the correct cap even if you have to order it. Clean the contacts of the old if you have to use it until you get a new one.

See if the fuse blows if you disconnect the throttle position sensor. Perhaps the trouble is within it.

I tend to agree with you. Hopefully replacing the switch will solve the trouble. Just had a thought about checking the parking light switch on top of the steering column. Does that work?

The P0446 error code refers to the evaporative emission purge valve so don't confuse it with the fuel pressure relief valve. Check the yel/red wire on the purge vavle and make sure 12 volts is getting to that point. Next check the power on the wht/blue wire of the solenoid and then see if the voltage is the same on pin A2 of the ECU. If it isn't then check the connection of B22 pin 2 and make sure it it is making good connection.

Another thing to do is check the area by the gas pedal and see if it pushing on an exposed wire and grounding it.

Fuses are usually the first thing in the power circuit to protect the whole circuit. The switch is after the fuse. The reconnecting the main harness connector at the firewall if you have there. There may be a faulty connection in it. I have heard of others solving this kind of trouble that way.

If the solenoid is making a loud click and nothing happens then the solenoid contacts are most likely bad inside it. You should be able to purchase new contacts and replace them. Be sure you have made sure that the battery connections are ok by cleaning then. They can cause the same thing to happen also.

It sounds like the trouble may be in one of the connectors. I suggest you start with the main connector at the firewall if you have one there.

Even though the alternator works after the unit is reved up it shouldn't do what it is doing. Whatever is making this happen the trouble is most likely inside the alternator. You can leave it as is if you want to.

From what you say, the alternator appears to be bad. The fusible link may be smoking because of a bad connection to it.

I take it you found a bad fuse.

It is critical that power tied to the battery warning light gets to the alternator field wire so the alternator can build a charging field. Power to the warning lights comes from the ignition switch and possibly through fuse 12. The wire coming from the warning lights to the alternator should be wht/red. To see if the alternator has a fault remove the connector on the back of the alternator and ground the w/r wire. Then turn the ignition switch to ON and see if the lights turn on. If they still don't turn on then there is a break in the w/r wire or power isn't getting to the warning lights. If the lights do turn on then replace the alternator.

The power to the voltmeter may be on a different circuit than the one to the warning lights.

That will work as well of course. Since the engine can be started then maybe the trouble is with the wiring to the dash.