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Discussion Starter #1
hope someone can help me find this electrical problem with my fuel pump and relay.

Changed fuel pump and relay (from dealer; manufacture date on relay was 2011) at 96k in September of 2012. Changed fuel filter in April of 2013 at 103k.

In July of 2014 car sputters, dies and won't restart but will crank. Check the fuse for the fuel pump in the trunk (which was fine) and then realize the fuel relay is extremely hot. Pull the relay and cannot touch the prongs because of the heat. Wait a few minutes and plug the relay back in and the car starts and runs fine. Drive few minutes and the car dies again. Relay is extremely hot again.

Get original relay that I had pulled out when I replaced the fuel pump (manufacture date of 2003) and swap it with the one put in in 2012 and car runs fine. Order a new fuel pump relay and keep in car just in case.

Driving today and car sputters and dies. Check fuel pump relay and overheated again. Swap with newest relay (manufacture date 2013) and car is fine.

Car has no other issues and ran fine between the relays burning out. No indication of a problem until car sputtered and died. Pulled codes and shows only bad fuel pump relay.

I have a multi meter that I got for free from Harbor Freight when I purchased some other tools but I am embarrassed to admit that I do not know how to use the meter.

Can someone suggest what might be causing the relays to "burn out." I know it is a module and not a simple relay. It could be the relay manufactured in 2003 just gave out but I don't want to get stranded again. I would hope the fuel pump I purchased would last longer than two years. Also, if someone can give me a diy on how to use the multimeter to test the wiring that would be much appreciated.

Thanks

Michael
 

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Sort of simple considering what you have put into the car. I will give you the tree so you can check. Normally I would say bad pump that is over drawing, but you replaced that so not likely. Prongs are the hottest. Some where in the powerline there is a bad connection making more current flow. Normally that blows the fuse but not always and for you, not.
Likely things to look at would be the the plug the relay sits in.

That means you will have to pop out the two large wires from the plug at the relay. Give the contacts a squeeze to make better contact, don't crush them, be gentle.. Repeat the same for the plug on the fuel pump. Likely the most important is confirm the ground for the fuel pump is sound, this is the most likely target. So follow the wire to where it joins the body.
 

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Discussion Starter #3
Thanks for the quick response Sailor.

Since the relay is relatively close to the pump I hope that it will not be too difficult to trace the wire to find the ground.

Is there anyway to test the pump to see if the draw is too high using the multi meter?

Michael
 

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Not really, guess is it is the relay plug because the prongs are hot. Some times the females in the plug don't line up well so one prong slides beside the female. Still touches but gets hot.
You could try a jumper wire but you will or should unplug it when the car is off. Could wire a simple on/off switch in it and see if this gets hot. Warning your fuel pressure will be high at idle, but no worries for testing for a few days.
The ground I speak of is from the pump to the body.
 

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Discussion Starter #5
I pulled the wiring harness from the bracket and about 1.5 inches of the insulation around the brown wire was gone and there was green corrosion around the exposed wire. The remaining edge of insulation was black so I suspect the missing insulation either melted away or from heating up became brittle and fell off.

the top of the wiring harness where the pin from the relay connects to the brown wire was slightly melted showing how hot the area is getting.

I cleaned off the exposed wire and wrapped the wire with electric tape in case there was any contact with the body.

Can anyone give me some help with removing the connector from the wiring harness so I can do a better job of insulating the exposed wire or maybe cutting off the connector and crimping on a new one?

Can anyone provide me with a part number or model number of the connector so I can get one.

I have not had the chance to pull the back seat and trace the wire from the fuel pump to the ground but does what I found indicate any other possible issues that can cause this?

Thanks again.
 

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I will have a look at my car to confirm but it is very poorly lit where it is. I am rarely up in daylight. Normally there is a small cutout in the opening where the prong goes down. A small pick or screwdriver slides down and pushes on a plastic clip. So push up on the wire slide the pick down from the top then pull down on the wire.
I suspect you will find it on one of these pages.
RealOEM.com Â* Diagram Selection
 

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Ok so what happened with the hot relay as i have the same issue when i opened the relay i found that the capacitor was detached from the board, probably due to vibration so i remade the connection, but the heat generated had melted the shellack on the board but no wire insulation, as i tested it the heat still seemed to great for a relay, i could be wrong i am now waiting for a replacement from the stealer 61 35 7 892 976
Any thoughts ?
 

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New relay arrived from BMW checked and found the quality of the capacitor to be poor only just made not even through the board at one end, now it is. So it was quite possible to vibrate loose as i have remade the original relay and put a link wire in, refitted to the car tested over o couple of hours driving checked and not even worn, so i think thats the over hearted relay problem is :wroom: SORTED !!!!!!!!!!!!!!!!
 
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