QuestionQUESTION: Hi rolan. First I want to say thanks for all of your help and especially your patience. I know it must be frustrating for you, I know it is for me. Anyway, your last reply said to test for 12 volts for at least 5 seconds when cranking. Where should I be checking for the 12 volts? At the "T" plug, the fuses, or the relay sockets (there is no sprk/voltage coming from the coil). Also, when I followed your trick for disarming the anti-theft/alarm, I put the pins in on wire #4 & #5 & bumped the pins together. Is that correct? Or should it have been pins 5 & 18? Finally, I have only listended for the fuel pump to go on when I just turn the key to "on", I did not keep listeneing when the engine is cranked because its hard to hear. is there another way to see if the fuel pump keeps working while cranking?
ANSWER: Hi Jim,
The 12V you would want to see is that going to the spark coil on the dark green/orange wire (upright of the T) as without that you won't get spark. On the disarm: either will work as one is from the driver and the other from the passenger door. You could verify that the fuel pump is getting voltage by checking the dark green/black wire at the plug for the oxygen sensor. If it hums for 1 second, and you see 12V on that wire while cranking then you know the fuel pump is running because that is another output of the fuel pump relay.
You are welcome. I hope this moves you along the way to running.
Roland
---------- FOLLOW-UP ----------
QUESTION: Roland, From your reply, it sounds like I can just use an
alligator clip on the upright part of the "T" plug while
cranking & hope I see the 12 volts for at least 5 seconds.
(Right now, I see 12 volts on both parts of the "T" plug
when the key is turned to "on", but I didn't check for 5
seconds of cranking. As far as checking the fuel pump
at the Ox sensor: Is that located on the exhaust pipe below the air cleaner assembly(hard to get to)? Am I checking for voltage, or a hum on the OX sensor wire?
(Sorry to be such a novice)
AnswerHi Jim,
I presume that you only see the 12V on the upright to last for 1 second or so when you turn the key to 'run'. On the crosspiece, that 12V would start oscillating to ground rapidly when you start cranking if there is a spark-triggering signal from the pcm, but you won't be able to 'see' it with a voltmeter circuit because the pulsing is too quick. But you should see the 12v return on the upright at the T when you start cranking and for as long as you crank. That is the key to knowing that the engine rotational sensors are putting out signals.
You would want to unplug the connector from the harness to the oxygen sensor and touch the pin that shown to carry 12V for the 1 second when the key is turned to run. As with the "T" you would look at that pin as proof that the fuel pump is getting its voltage while the engine is cranking. You would need to use the voltmeter (there is no 'hum' on that sensor. Yes it is located on the exhaust manifold. I am not encouraging you to go to this trouble, if you satisfy yourself about the voltage at the T-plug, as while they are outputs from different relays the pcm would not drive one but not the other.
Roland
Roland
