Hi there! I have a check engine light thats ignited in my automobile. Everything under the engine is fine, but the light is on, what do I do and how can i resolve this dilema? Thank you for your assistance! Janna

Before you pull the starter and have it bench tested put a 12v tester light on the starter leads, I am betting on the starter solenoid

All automobiles have a kind of power transfer port. The battery and everything requiring a 12volt supply passes through the wiring harness. Most everything gets its ground from the frame. So If all power is lost suspect the harness. Otherwise there would be power failure at whatever refuses to work. So check at the wiring harness. Carefully probe the harness under the hood at the fire wall. all the power gets to its destination on the other side of the harness that is inside the car under the dash. If there is no voltage outside there is a great likelihood that none will be inside. Your problem is interesting, you will discover it soon, just by eliminating things in a logical fashion. Post again if none of this has helped you. Finally, try to recall the last thing you were doing before everything quit.

Do you know how to do electrical testing using a DVOM - digital volt ohm meter ? How to use a wiring diagram to find test point's in a electrical circuit ? This how we find an fix electrical problems on automobiles .
Electric Testing Techniques You Need to Know

can it be the starter ignition switch?? Guessing is not the way to a fix . TESTING is !!!! Maybe you fried the PCM - engine computer !

http://www.bbbind.com/free_tsb.html free wiring diagrams . Enter your vehicle info. year , make , model an engine size... Under system click on electrical distribution , then under subsystem click on power distribution . Click the search button .Then click on the blue links one at a time . Take your volt meter an check for B+ voltage into the ignition switch then in start test for B+ voltage out . And if you don't know how to test like this ,your best bet would be to take your vehicle to a qualified repair shop that does !

maybe the oil got on your computer and shortened it out maybe you need to replace the unit that the oil got on

Go under the dash and check to see if the ignition starter switch is coming apart is the first thing to check. The switch is operated by a long rod from the ignition switch, it is near the base of the steering column tube on top of it. The other poss is that the tilt steering is going south and needs new parts for the rod actuator down to the switch.

P1607 means "powertrain control module (PCM) internal circuit malfunction". According to the factory service manual, a low battery condition can cause this. This code can also pop up after the battery has been jump started.

You need to reset the PCM. To do this, turn the ignition switch off. Remove the No. 13 fuse (7.5Amp) from the passenger's under dash fuse/relay box for at least 10 seconds. Put the fuse back in. That should complete the reset.

Now to check again for the code: turn the ignition switch to on (not start.) Wait 30 seconds. If the check engine light stays OFF, turn the ignition switch off and wait 10 seconds. Turn the ignition switch back to on (not start). Wait 10 seconds. If the check engine light stays OFF, you had an intermittent fault and it has now been reset--everything is fine. If the check engine light comes back on during these checks, have the code that set read out. If the code is P1607 again, then you may have to have the PCM tested at the dealership for an internal fault.

1991 Ford F150

Vehicle Battery Positive Wire (+): Yellow
Vehicle Battery Positive Wire Location: Ignition Switch Harness
Vehicle Ignition Wire (+): Red/Light Green
Vehicle Ignition Wire Location: Ignition Switch Harness
Vehicle Second Ignition Wire (+): N/A
Vehicle Second Ignition Wire Location: N/A
Vehicle Accessory Wire (+): Gray/Yellow
Vehicle Accessory Wire Location: Ignition Switch Harness
Vehicle Second Accessory Wire (+): N/A
Vehicle Second Accessory Wire Location: N/A
Automobile Engine Starter Wire (+): Red/Light Blue
Automobile Engine Starter Wire Location: Ignition Switch Harness
Automobile Second Engine Starter Wire (-): N/A
Automobile Second Engine Starter Wire Location: N/A
Factory Anti-Theft System: None
Factory Anti-Theft System Type: None
Car Key Sense Wire (-): Black/Pink
Car Key Sense Wire Location: At Steering Column Harness
Car Neutral Safety Wire (+): N/A
Car Neutral Safety Wire Location: N/A
Car Tachometer Wire (-): Tan/Yellow
Car Tachometer Wire Location: At Ignition Switch Control Module in Driver Fender Well
Car Speed Sense Wire: Gray/Black
Car Speed Sense Wire Location: Pin #3 at PCM Mounted on the Firewall
Car Parking Lights Wire (+): Brown
Car Parking Lights Wire Location: At Headlight Switch or Driver Side Kick Panel
Car Brake Lights Wire (+): Green
Car Brake Lights Wire Location: At Brake Switch Above the Pedal
Car Reverse Lights Wire (+): Black/Pink
Car Reverse Lights Wire Location: At Switch on Transmission
Car Horn Wire (-): Blue
Car Horn Wire Location: At Steering Column Harness

Sorry friend, this is as far as i can go to tel you how to hot wire the ignition. But with the color codes you should be able to figure it out, Good luck and keep me posted.

Hi, I can tell you that I was having a simular problem with my 2001 Chevy Silverado. The check engine light would come on and I lost both the speedometer and odometer. I also lost gas gauge, and oil pressure gauge.I would hit a bump and they would start working, but light would stay on. I bought the obd-2 meter to read codes and erase them so the light went off. This continued for 8 months. Finally, I started moving wires around under dash when gauges stopped and they would come on and off? Took me right to the circuit board on the ignition switch. I mean I tried everything possable to solve this and told a G.M. mechanic. He said I was right that it would be the switch and that most of you're wires that go to gauges and speedometer come from the ignition switch. I changed it and it has been fine since. You might try what I did see if you can do this while driving, i don't no, but if so be carful on the road. You may need to take it in also.There is something loose a ground wire or hot doing this. I would bet it is in the ignition switch. Best of luck,
Shastalaker7

i checked the computer. Following error is showing:
1. P115
2. P1300
3. P1565
4. P1349
5. P1656