Don Hall
Full Access Members
Had the same problem with the same solution.
Glad it all worked out for you.
Glad it all worked out for you.
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So I know there is a bunch of people that like to replace the CJB (Fuse Panel). But remember that all you are doing is resetting back to the same potential problem being able to happen again. The circuit board was not designed properly to take the heat from those undersized relays. If the PCM relay is good, and you only fried the fuel pump relay, I recommend just putting an external relay on and wiring it in. There are videos to do this, but a lot of them suggest wiring it in improperly so that the fuel pump runs whenever the ignition switch is on. I have an 05 Expy and this is the proper way to wire in an external relay....
First... buy one of these external relay kits... its rated for 30 amps.
https://www.amazon.com/gp/product/B074QV54V1/
And one of these (mini fuse tap) ...
https://www.amazon.com/dp/B01LFXA5UA/
And you will need some inline power taps...
https://www.amazon.com/dp/B07WFPFY1C/
Then wire it in as follows...
Your relay has 5 wires. You don't need the center one. So all you need are the 30, 85, 86, and 87 terminals that correspond to the relay harness. 30 is power always on, 85 is a ground that activates the relay (it completes the pin 86 circuit), 86 is powered when ignition is on (engine running or not), 87 is power out only when the relay is engaged (this will go to the fuel pump)
The reason most videos are wrong is that they wire the ground to a normal ground. This means that the minute you turn on the car the fuel pump runs constantly. How its supposed to work is that the PCM has a ground going to the fuel pump relay that is only on 1.) when you first turn the ignition to the on position and its only grounded for the 2 seconds of priming then disconnects and 2.) When your car starts and it then needs constant power to the FPDM (Fuel pump driver module)
So what you want to do is to replicate that circuit that includes the ground from the PCM. Here is a way to do it that works the way it should...
First you need power to the new relay... fuse 9 (15) amps will work because its KOEO (Key on Engine Off).
Wire that Using a fuse tap to get power for the pump, fuse 9 (15A), wire that to 30 on your relay. Use a 20 amp fuse for the second fuse (put the 15 amp fuse on the lower socket the 20 amp on the upper socket. Basically you just made a new circuit.
On the C270A plug there is a red/yellow wire... that is Key on Engine off or on power. Basically power that only goes on when the ignition circuit is active. Use an inline tap to wire that to the wire that corresponds to 86 on your relay.
On C270B, there is a thinner guage black wire in the corner of the plug. This is ground from the PCM. On some years I believe its LT BLUE/Orange, but for 2005 its black. You can cut it or do an inline splice... I always opt for the inline splice for grounds. It is pin 12 of c270B and wire the harness side of it to 85 of your relay using an inline splice.
Now the relay should work, and you can test it before doing the final connection by turning the ignition on and you should hear a click from the relay. If this woks, you now just need to feed power to the FPDM.
The dark green/yellow wire of C270B feeds power to the FPDM... cut that and wire it to terminal 87 of your new relay.
Your car now has a better, and replaceable external fuel pump relay. Doing it this way will not fry your CJB and is easily replaceable if it were ever to fail again.
Ok followed instructions and it now starts but cuts off immediately. New fuel pump, new filter, and the relay.So I know there is a bunch of people that like to replace the CJB (Fuse Panel). But remember that all you are doing is resetting back to the same potential problem being able to happen again. The circuit board was not designed properly to take the heat from those undersized relays. If the PCM relay is good, and you only fried the fuel pump relay, I recommend just putting an external relay on and wiring it in. There are videos to do this, but a lot of them suggest wiring it in improperly so that the fuel pump runs whenever the ignition switch is on. I have an 05 Expy and this is the proper way to wire in an external relay....
First... buy one of these external relay kits... its rated for 30 amps.
https://www.amazon.com/gp/product/B074QV54V1/
And one of these (mini fuse tap) ...
https://www.amazon.com/dp/B01LFXA5UA/
And you will need some inline power taps...
https://www.amazon.com/dp/B07WFPFY1C/
Then wire it in as follows...
Your relay has 5 wires. You don't need the center one. So all you need are the 30, 85, 86, and 87 terminals that correspond to the relay harness. 30 is power always on, 85 is a ground that activates the relay (it completes the pin 86 circuit), 86 is powered when ignition is on (engine running or not), 87 is power out only when the relay is engaged (this will go to the fuel pump)
The reason most videos are wrong is that they wire the ground to a normal ground. This means that the minute you turn on the car the fuel pump runs constantly. How its supposed to work is that the PCM has a ground going to the fuel pump relay that is only on 1.) when you first turn the ignition to the on position and its only grounded for the 2 seconds of priming then disconnects and 2.) When your car starts and it then needs constant power to the FPDM (Fuel pump driver module)
So what you want to do is to replicate that circuit that includes the ground from the PCM. Here is a way to do it that works the way it should...
First you need power to the new relay... fuse 9 (15) amps will work because its KOEO (Key on Engine Off).
Wire that Using a fuse tap to get power for the pump, fuse 9 (15A), wire that to 30 on your relay. Use a 20 amp fuse for the second fuse (put the 15 amp fuse on the lower socket the 20 amp on the upper socket. Basically you just made a new circuit.
On the C270A plug there is a red/yellow wire... that is Key on Engine off or on power. Basically power that only goes on when the ignition circuit is active. Use an inline tap to wire that to the wire that corresponds to 86 on your relay.
On C270B, there is a thinner guage black wire in the corner of the plug. This is ground from the PCM. On some years I believe its LT BLUE/Orange, but for 2005 its black. You can cut it or do an inline splice... I always opt for the inline splice for grounds. It is pin 12 of c270B and wire the harness side of it to 85 of your relay using an inline splice.
Now the relay should work, and you can test it before doing the final connection by turning the ignition on and you should hear a click from the relay. If this woks, you now just need to feed power to the FPDM.
The dark green/yellow wire of C270B feeds power to the FPDM... cut that and wire it to terminal 87 of your new relay.
Your car now has a better, and replaceable external fuel pump relay. Doing it this way will not fry your CJB and is easily replaceable if it were ever to fail again.
Did you wire it to the dark green /yellow wire from c270k because I believe David's post had a typo. I posted it right before your post along with the picture you are talking aboutOk followed instructions and it now starts but cuts off immediately. New fuel pump, new filter, and the relay.
I must have been typing as you were posting the pictures. lol. But yes I did do it to c270k. I had to arched some videos and did do that. My thing is that now it actually cranks but then shuts off as soon as I let off the key from start mode to run mode. I have tried the fuse in 9 and a couple others. I even switched the two relay wires (30 & 87) no change. I tried different grounds, no change. I know the original relay was part of my problem because it was crank no start and now it is crank with start. Just not continuous run.Did you wire it to the dark green /yellow wire from c270k because I believe David's post had a typo. I posted it right before your post along with the picture you are talking about