hope2

Stock car, won't start. Was able to fix swapping relays. Filled tank, drive home. Now only way is to power pump is direct. Grey pump wire fuse box burned pin. Want to wire a generic relay. Read thru many threads. Need clarity on the trigger wire from pin 50 of the ECM. Says goes into E7 of the relay. Says D-GN/WH. Doesn't exactly tell me which wire in the harness it is. There are two green/white wires near the grey pump wire. Is it in the same connector as the grey wire?

Don't think I'm reading the schematic right.

How do I get from E7 to the actual wire?

To be sure, should have battery voltage when cranking? Correct?

Dano523

Lost here,

Did you burn the wire from the fuse box to the fuel pump with too much load on the Oem wire going back to the pump with say a BAP wired to into it, or the trigger wire from the ECM to the relay coil side on the fuse box isntead?


MM6, C1 connector (blue socket on ECM)

pin 45 D-GN/WH circut 465 Fuel Pump Relay Control - Primary

Looking at the C1 connector, with the pins towards you, round outer cap end to the right/square outer cap end part to the left, will be the third pin from the left on the top row.

As for the lower block socket female snap in connector clips if it being burnt is the only problem, Mouser has replacement connectors, so pick tool to remove the burnt connector out the bottom of the block, crimp the new one to the wire, and then push the connector back in place from the bottom side to snap it in place back in the block.


Hell, if you want to cheat/get lazy for a new connector instead of ordering a few from mouser, then get a low beam jumper for the low beam Recall, and use one of the connectors with wire from it to replace the burnt connector in the lower block.



Hence the last thing I would do is rig in aftermarket relay to replace the OEM relay in the fuse block, since sooner or later, someone else down the road is going to own the car, and the last thing they want to do is try to figure out what you jerry-rigged to repair the car before hand isntead.

Hence if you did burn the wire way down at the ecm connector, the replace the pin with the correct wire color, pull it back to the fuse block lower box through the wire loom, then install it on a new connector to snap back in the lower gray block.

If you burnt the Oem wire from the fuse block to the pump connector, then same-same as well.

Hell, if you have problem in the upper fuse block assembly, easy enough to pull its covers to repair it instead.

hope2

points taken. cannot get the A6 to fuel pump pin out of the connector. as i said been hot, will try again.

Dano523

Photo would help.

hope2

moving along. got the pin out. plan is replace pin with new wire and splice to original wire. now to find new pin or a low beam recall harness.

hope2

Problem solved. Replaced pin A6 that goes to pump. Used the recall kit for the low beam. Thank you Dano523

Dano523

No worries, since the recall jumper you can pick up from most dealers since they have them in stock, but in the future and have more time, order the needed electrical parts from Mouser Electronics instead.

Telepierre

Apologies for reviving this but I have the same "cranking but no start" fuel pump issue on my 2008 A6 with BAP.

Read through many threads. Inspected relays, connectors both outside and inside the disassembled fuse box. No signs of corrosion nor burnt wires.
The only thing that works and gets my car started and running is to jump the two upper right/lower left relay receptacle. I suppose that keeps the pump constantly running up to pressure or all the time..

Does a new box fix this permanently?
Can I drive the car for 40 miles with the jumper in?

Thanks!

hope2

swap relay. check terminals with volt meter.

Telepierre

Will do. Thanks!

Dano523

You have bigger problems at hand ,but jumping the relay for a short time will allow you to drive the car the needed distance

Now back to the problem at hand, and that is the relay in the fuse box, should only be sending power to another 40 amp relay to power that relay up on the coil side.



Now on the second added relay, it gets fused power in to it on the its common leg from the battery, the No leg wire the correct gauge goes to the BAP, then the positive wire out of the BAP with the correct gauge wire goes all the way back to the fuel pump connector at the tank to be wired in there.

Hence you do not use the fuse box relay to send power directly to the BAP since it drawing too much amperage and will burn up the oem relay in the fuse box quickly (and it connector points in the upper and lower fuse blocks as well), and you sure in hell don't use the small gauge OEM wiring from the fuse box location to send the BAP power down to the fuel pump since it will burn up that oem light gauge wire with too much amperage power through it as well.

Hence the boost a pump works by sending out a high voltage with more amperage to cause the fuel pump to spin faster (and burn it out faster as well). so with a second 40 amp relay used that can take the additinal amperage load, the OEM relay in the fuse box only sees about 450ma of power to drive the second relay and does not burn out the OEM relay. Also, since the power is from the battery to the BAP (controlled by the second relay), then to the fuel pump connector all the way to the back connector for it, you don't end up burning up the small gauge OEM wiring from the fuse box to the fuel pump.

https://www.corvetteforum.com/forums...right-bap.html

Bluntly, not a fan of the BAP, since it just over driving the OEM fuel pump to start with, which means that you going to be dropping the tank sooner than later to replace the tank fuel pump once it does burn out from begin over driven in the first place.
Hence drop the tank from the start, install a higher volume/pressure fuel pump in the tank like the LS9 fuel pump, or install a secondary fuel pump in line from the start with is needed wiring, so your not sitting on a BAP that your not going to be using when the OEM fuel pump burns out shortly, and replaced with a higher volume/pressure fuel pump instead.

Telepierre

Thank you much for relaying the correct setup & diagram.
I should have stated from the beginning the BAP setup is as intended (no shortcuts) and has been working for 5+ years with a new Z06 pump. Also the the problem is intermittent. For example, after the fuse box disassembly and cleaning I repositioned the fuse box relay and nothing. Then I jumped the two receptacles and it works. New relay back in - nothing. THEN I left the car overnight with no jumpers nor relay plugged in, when in this morning, put the same relay in, and...it works!!

It seems an intermittent failure rather than a burnt element.

Next check is the BOSCH relay? I guess that could be it as well or maybe the BAP reach-lean rheostat? The rheostat **** gets rather "mushy" when the engine bay is warm..

Dano523

You might have a problem with either the lower fuse block connector pushed down, or could be a problem with the upper fuse block U clips for the relay spades heated open or even the trace wire in the upper fuse block instead.

So would start with pulling the upper fuse block to check the lower spades of the upper block and the connector pins of the lower blocks for any sockets they may have been pushed down, or started to melt.
[img]https://lh3.googleusercontent.com/-hK7KFNhuOOc/UQYcaBnUZRI/AAAAAAAABJI/DIq94j-lOLg/s912/2013-01-27%252016.09.52.jpg[img]

But the fact a good relay did not work, while the jumpers worked, could be a problem up line with the coil side of the relay (multi meter to check the other two pins on the fuse block not used to jump the relay to confirm 12 voltage) or could be a problem in the upper block.

So if you put a multi meter on the other two fuse block relay pins that you did not use to jump the relay with the car in on mode, and don't get 12 volts, it your problem.
If you do get 12 volts on these pins, and the good relay is still not working/don't have problems in the lower fuse blocks, then may need to split the upper fuse block to straight the widened U pins so they make a good connection with the relay spade legs.



https://www.corvetteforum.com/forums...dlights-5.html

Telepierre

Thank you much for pointing me to the specific points to test and measure. I do think the issue is the fuse box as well and will check as indicated.

Dano523

With the oem relay used to power up the BAP directly, instead of a second 12v 40 amp relay power up the BAP, and the OEM relay just sending voltage (450ma) to that the 40 amp relay to control it on it coil side, it will cause problems with the upper fuse box.

Most of the time is just the heat to the U slot pin that the relay legs clip to, that cause them to spread apart so they are not making a good contact to the relay legs, but it can cause problem where the trace wires in the upper fuse block board wedge clips to the sides of the U slot to cause a bad connection there isntead.

Forget the red circle but look at the U prongs and how the trace wires are wedge locked to the U pins instead.



If the U slot prongs are bent open, then pliers works to bend the two legs back closed to normal position, while on the side trace wires to where they clip in, have see that connector point so heat problem'd, that you have to break out the soldering iron to solder the trace wire to the side of the U prong at its wire clip in point to get a correct needed connection instead.

Hell, have seen the U connector so heat burn to hell, that it a matter of breaking out a file to clean the contact points, then slightly over bending the U slot tabs a touch more closed to normal to make a good contact to the relay leg isntead.


Also, take a hard look at the lower blocks that the upper fuse block spade on the bottom it connect to on the lower blocks. You could have one of the female spade connector pushed down in the block that the upper fuse block spades are not making a good connection to when it installed, find one of them melted instead.

Bottom line, once you get the fuse block corrected, then make sure to wire the BAP correctly on its own larger gauge wiring (so you not using the oem relay to send power to the BAP directly), and make sure that you have large enough gauge wire on the BAP wiring all the way back the fuel pump connector at the tank as well (hence not using the OEM wire from the fuse box to the fuel pump connector to send the BAP voltage to the pump.

Vets-Vet

Have you checked voltage at the pump ? Have you checked the fuse labled FR ? Have you checked fuel pressure with a gauge?

https://www.corvetteforum.com/forums...post1605973487

uBoatjoe

Hi,

Thank you for all the information. I have a 2013 C6 with a no crank issue after the engine run for a while. I am looking at the fuel pump relay and possible damaged to the fuel pump connector in the wire harness box (lower block).

Can someone give me a part number for the replacement connector from Mouser ? Having a hard time finding that particular connector.

Thank you