pcm power problem!!
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pcm power problem!!
Let's start from the beginning.
I have an 03 f150. After loading it up for a big kayak trip, it wouldn't start. The odo read all blanks and the theft light was blinking rapidly( for about a min, then the "16 code")
Soo I checked all the fuses and relays with multimeter and they all checked fine. Checked all the connections and everything else right in front of me.
Soo this is where I'm stumped. On the pcm relay, I get constant power on the bottom pin. I also get power when the key is on to the right pin. The ground is good(left pin), as I used it for the test.
Now if I jump power from the battery to the top pin the truck starts right up. No theft light, and the odo is fine. So I replaced the relay, even though it tested fine, because that had to be it...right? Still nothing...
Sooo help!!! Not really sure what that means, or where to look. Any tips would be appreciated.
I have an 03 f150. After loading it up for a big kayak trip, it wouldn't start. The odo read all blanks and the theft light was blinking rapidly( for about a min, then the "16 code")
Soo I checked all the fuses and relays with multimeter and they all checked fine. Checked all the connections and everything else right in front of me.
Soo this is where I'm stumped. On the pcm relay, I get constant power on the bottom pin. I also get power when the key is on to the right pin. The ground is good(left pin), as I used it for the test.
Now if I jump power from the battery to the top pin the truck starts right up. No theft light, and the odo is fine. So I replaced the relay, even though it tested fine, because that had to be it...right? Still nothing...
Sooo help!!! Not really sure what that means, or where to look. Any tips would be appreciated.
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Bottom- 30
Right-86
Left-85
Top-87
Or something like that. Left and right may be switched around.
But ether way, I have the right power in the right places.
Hotshot
Joined: Jan 2004
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From: St Louis
On the pcm relay, I get constant power on the pin 30.
I also get power when the key is on to the right pin 86.
The ground is good pin 85
jump power from the battery to pin 87
Your readings indicate a bad relay or one that is not connecting properly.
Swap the PCM power relay with the horn relay and see what happens, assuming that the horn works properly.
I also get power when the key is on to the right pin 86.
The ground is good pin 85
jump power from the battery to pin 87
Your readings indicate a bad relay or one that is not connecting properly.
Swap the PCM power relay with the horn relay and see what happens, assuming that the horn works properly.
Thread Starter
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On the pcm relay, I get constant power on the pin 30.
I also get power when the key is on to the right pin 86.
The ground is good pin 85
jump power from the battery to pin 87
Your readings indicate a bad relay or one that is not connecting properly.
Swap the PCM power relay with the horn relay and see what happens, assuming that the horn works properly.
I also get power when the key is on to the right pin 86.
The ground is good pin 85
jump power from the battery to pin 87
Your readings indicate a bad relay or one that is not connecting properly.
Swap the PCM power relay with the horn relay and see what happens, assuming that the horn works properly.
Well I tested the original relay and it opened fine, I then swapped it with a relay that tested fine, then after all that I even bought a new relay that tested fine.
But nothing!!
Hotshot
Joined: Jan 2004
Posts: 19,768
Likes: 1,082
From: St Louis
:shrug:
Don't know. Your data says it should be working perfectly. Therefore, either something in the data is wrong or there is something nearly imperceptible that you've overlooked, perhaps a loose or intermittent contact in the relay socket that isn't making good contact with the relay terminal but your meter probes can contact just fine.
Don't know. Your data says it should be working perfectly. Therefore, either something in the data is wrong or there is something nearly imperceptible that you've overlooked, perhaps a loose or intermittent contact in the relay socket that isn't making good contact with the relay terminal but your meter probes can contact just fine.
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From: Central NYS
When you test these relays are you using the pin 86 socket for the power source to pull the test relay in?
If not, pin 86's power source is protected by a diode. Perhaps the diode is not passing enough current to pull the relay in and therefor pin 87 never sees any voltage (unless you jump battery power to it
).
If not, pin 86's power source is protected by a diode. Perhaps the diode is not passing enough current to pull the relay in and therefor pin 87 never sees any voltage (unless you jump battery power to it
).
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