- Thread starter
- #21
Jon, does this corrosion need to be addressed?
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Jon, does this corrosion need to be addressed?
LOL, It's not corrosion. It's old dried up grease. I doubt it will hurt anything, but if you feel like cleaning it out then go for it. I would never advise against cleaning something.
That will work fine. Individual parts for the internals of relays is not something that gets replaced. You'd just buy a new relay, but we're not ready to start spending money yet.
IIRC, the pinout should be printed on the side of the relay.
Remove the COR and check for a good solid ground on pin 6 of the relay socket. Set the dial on the meter to 200 ohms (green omega section). Put 1 probe on pin 6 and the other on the ground lug to the left of the relay block that's screwed into the sheet metal. You're looking for a reading close to 0 ohms.
If that's good, then check for voltage between pins 3 (red probe from the meter) and 6 (black probe from the meter).
Set the dial on the meter to 20 VDC (V=) then place the probes on the relay socket. You're looking for approx +12 volts when the starter is cranking. If both of these tests are good, then replace the COR, as the logic that controls the relay is good.
Yes.
All positions on a connector have to be designated so you know where the wires go. There are 6 positions on that connector. It makes no difference if several are unused. The designations of the positions have to stay the same. In this case, pin 5 is not used.
In your first picture the meter is not set the way I asked you to set it. You're on a high resistance setting of 200K ohms, not 200 ohms. Please set the meter correctly and recheck the ground path.
Below you'll see the schematic of the COR connector along with the factory wire colors. Be certain you're on the correct terminals when measuring.
Pin 2 (yellow/red stripe) will be +12 with the key in the ON position.
Pin 3 (black w/ red stripe) will have voltage ONLY when the starter is cranking. Voltage will be less than +12 because the starter is cranking.
Pin 6 (brown) will always be ground.
In your first picture the meter is not set the way I asked you to set it. You're on a high resistance setting of 200K ohms, not 200 ohms. Please set the meter correctly and recheck the ground path.
Below you'll see the schematic of the COR connector along with the factory wire colors. Be certain you're on the correct terminals when measuring.
Pin 2 (yellow/red stripe) will be +12 with the key in the ON position.
Pin 3 (black w/ red stripe) will have voltage ONLY when the starter is cranking. Voltage will be less than +12 because the starter is cranking.
Pin 6 (brown) will always be ground.
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I also see at least 4 non-OEM wire splices with butt connectors in these pictures. Someone has been in there before you.
- Thread starter
- #32
Thank you @jonheld! I will readjust the meter settings and retest. Am I to assume that the photo you send me is reflective of a straight on view? In other words, are position 2 and 3 on the top and 1,4, and 6 on the bottom?
Any idea what wires are spliced? I know he has an aftermarket security system hooked up. What do you think of the possibility of someone wiring something for an auto starter that may be causing this issue? Just a thought.
Thank you!
Chris
No. A schematic is not a mechanical view, it is the electrical connections only. The mechanical layout is usually printed on the side of relays, but might not be in this case. However I gave you enough information in my last post for you to figure things out. I believe in you.
No idea, but with a closer look, I see 7 splices. Hard to know unless you start tracing wires back to OEM connectors and reverse engineer what was done. This is not something that can be done via the internets.
At this point, I'm pretty confident that the COR is faulty, assuming the ground path is truly a ground path. Please recheck.
Let's keep in mind that the second coil of the COR works as designed, because once the engine starts, it stays running. You can verify this.
Replace the COR. Start the truck with your little jumper wire in the diagnostic connector. Remove the wire once started and the engine should continue to run.
Now disconnect the connector on the AFM by lifting the spring clip on the sides of the connector.
***** DO NOT UNSCREW THE 2 PHILLIPS HEAD SCREWS ON THE SIDE OF THE CONNECTOR HOUSING. *****
The engine should stall 1 or 2 seconds after the AFM has been disconnected because the fuel pump shut down. If this is all true, then the system is working as designed.
Also, there are a number of white/black stripe wires that are connected to a screw threaded into the body. That is the ground point I was talking about to use, but the one you used with the single black wire should work just as well, assuming the screw is making good contact with the metal.
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- Thread starter
- #35
Thank you, Jon! I believe in my abilities to follow your AWESOME instructions, just trying to get all your input while I am at work, I mean... not at work? Ha!
I will take a peek at the wires when I get home, I am sure I can figure them out if they are color coded. I will also call a few local Yota yards to see if they have a COR handy. Otherwise I am heading online.
Thank you! More to come...
Let's find out. I don't have a schematic for a 93. The later ones (96/97) appear to be different, but if it has the same number of pins, I would have to say yes.
I just did a brief search and it appears to be the same part from 91-94. Go for it.
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- Thread starter
- #39
@jonheld Got the "new" COR from the Yota yard. Plugged it in and it fired up 4/5 times in a row. I let her sit for about an hour and went out, popped the hood and had my gf try. No luck after 3/4 cranks. About 10 mins later, I tried again and she fired right up. I did this 3 or 4 times without issue. Im not sure if my gf over cranked and put too much fuel in the engine or what.
I am planning on going back out and trying the process we dicussed yesterday to make sure the Ohms are reading correctly. More to come!
Thank you!
- Thread starter
- #40
UPDATE!!!
It appears that both the new and old COR have the same symptoms. I am not sure why the truck turned over when I replaced the COR this afternoon, however all the same problems are persisting. It seems the only fix is still to spray starter fluid in the intake as I tried that during and after my testing.
@jonheld I tried to run the engine with the wire connection in the diagnostic connector. I pulled the connector on the AFM and the truck died immediately. That test works.
Multimeter testing (see my attached COR photo diagram):
I tried my best to get my head back in the wheel well and see which wires connected to each position. I tested as instructed. Position "2 middle" while the ignition was turned to "on" resulted in 10-12 V. Position "3" while cranking resulted in a little less than 8 V. Position "6" was tested as the ground, reset the Ohms to 200 and it read between 0.0 and 0.2.
***EDIT***!!!!!!
When I test the ground, my multimeter plays a siren. Does this mean a broken ground?
Not sure where to go from here. Bad fuel pump? Bad ground?
Thank you!
It appears that both the new and old COR have the same symptoms. I am not sure why the truck turned over when I replaced the COR this afternoon, however all the same problems are persisting. It seems the only fix is still to spray starter fluid in the intake as I tried that during and after my testing.
@jonheld I tried to run the engine with the wire connection in the diagnostic connector. I pulled the connector on the AFM and the truck died immediately. That test works.
Multimeter testing (see my attached COR photo diagram):
I tried my best to get my head back in the wheel well and see which wires connected to each position. I tested as instructed. Position "2 middle" while the ignition was turned to "on" resulted in 10-12 V. Position "3" while cranking resulted in a little less than 8 V. Position "6" was tested as the ground, reset the Ohms to 200 and it read between 0.0 and 0.2.
***EDIT***!!!!!!
When I test the ground, my multimeter plays a siren. Does this mean a broken ground?
Not sure where to go from here. Bad fuel pump? Bad ground?
Thank you!
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