Fuel Pump Relay??
- Thread starter Jm123
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Blobcat
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I don't know which is you fuel pump relay but unless you want wet feet and smelly carpets I would remove all the leaves and fir tree bits from under the bonnet. Your drain holes are probably clogged already.
lepton
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Where are you? I have a working spare taken from a 1990 300SE which you can try out to see if the problem is the fuel pump relay. Can't get it until Monday though. What makes you think it's faulty?
Alan
Alan
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Hi Alan,
I had a mechanic come round and isolate the ignition problem which he nailed to the fuel pump relay. I'm in Dunstable, Beds but i've just had one turn up from Euro Car Parts (The wrong one as well from the looks of it as well!!).
Cheers for the offer!
I had a mechanic come round and isolate the ignition problem which he nailed to the fuel pump relay. I'm in Dunstable, Beds but i've just had one turn up from Euro Car Parts (The wrong one as well from the looks of it as well!!).
Cheers for the offer!
television
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You can bridge the contacts or run a seperate 12v wire to test, to see if the pumps run
http://www.detali.ru/cat/oem_mb2.as...&L=765.706&CT=F&cat=568&SID=54&SGR=045&SGN=03
its item 161 in the above with part numbers.
Malcolm
http://www.detali.ru/cat/oem_mb2.as...&L=765.706&CT=F&cat=568&SID=54&SGR=045&SGN=03
its item 161 in the above with part numbers.
Malcolm
lepton
Senior Member
Fuel pump relay
The relay is shown on your photograph. It's the black box to the right of the fusebox and in front of the master cylinder/servo unit. Mine has a number - 003 545 24 05 and a sort of a barcode printed on top.
Alan
The relay is shown on your photograph. It's the black box to the right of the fusebox and in front of the master cylinder/servo unit. Mine has a number - 003 545 24 05 and a sort of a barcode printed on top.
Alan
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That's what the mechanic did. He ran the 12v wire to test it and the car started first time.
Had confirmed by the supplier that the relay is the right one for the car but......still no joy so it looks like i'm down to the wiring.
I can feel a garage visit coming on............
Cheers for your input so far gents!
Had confirmed by the supplier that the relay is the right one for the car but......still no joy so it looks like i'm down to the wiring.
I can feel a garage visit coming on............
Cheers for your input so far gents!
television
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That's what the mechanic did. He ran the 12v wire to test it and the car started first time.
Had confirmed by the supplier that the relay is the right one for the car but......still no joy so it looks like i'm down to the wiring.
I can feel a garage visit coming on............
Cheers for your input so far gents!
Do you have a voltmeter.
Malcolm
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If you're sure you've 100% got the right relay and that does'nt cure it I'd be having a serious look at your fuses from what I can see in your photo the contact tips of nearly all your fuses look extremely dirty and covered in verdis gris ie green corrosion found on copper. The old type continental fuses are notorious for failure at their tips they even arc and I've seen them with a cicle bunt in the tip where they fit in the holders. The fuel pump fuse is particularly prone to this as quite often it can become overloaded by the fuel pump(high amps draw) if and when the filter gets blocked.
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No to the voltmeter....stupid question but what would i do with it in this instance?
Re the fuses, they were all checked when the mechanic had a look on Saturday morning. They're all working fine and dandy but i agree, they do need looking at.
Thanks again for all the hints and tips here as well......i'm actually learning something here.
Re the fuses, they were all checked when the mechanic had a look on Saturday morning. They're all working fine and dandy but i agree, they do need looking at.
Thanks again for all the hints and tips here as well......i'm actually learning something here.
television
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With a volt meter you could see where the 12volt starts and stops, ie, you should have 12v on pin 30 of the relay, without know that its impossible to go further.
Malcolm
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Did your mechanic feed 12v straght to the pump under the car to get the motor running or just to the "out" side of the pump fuse? If straight to the pump then possibly there is no feed to the pump relay let alone out of it to the pump. As Malcolm says you need a voltmeter to see where and how much voltage you've got and where, you could possibly get by with a test light :???:
GEORGEROV
Senior Member
Hi jm, Don't forget the fuel pump relay gets a control signal from the ecu . Hope thats not the problem!.
television
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I do not have much info for the 123. Most MB relays use the same coding pin 30 is the input, and where there is an output, this is pins 87.
The fuel pump relay is controlled by the the speed limiter on the 124 and 126 and does so by cutting the fuel pump. This info comes from the engine ECU and operates at 4k.
Only by having a voltmeter can you check where everything starts and stops.
Do bear in mind that though there were wiring and fuse holder problems on the 124, the 123 is now getting quite old and wiring used in high current situations can become brittle as can the contacts on the fuse holders.
Running wires direct from the battery can also damage components if you do not remove the relays in question that were or are suppling the voltage or power to the component that you are testing. So by joining a wire from the battery direct to the fuel pump you are effectivly going to blow any other components that switched it off in the first place, and the fault will soon become a multiple job. Most things that come into my workshop, that has been got at by the owner are scrap and unrepairable, I am talking electronics here not cars.
You cant see electricity, nothing moves to the eye, one faulse move on these relays panels blows the semiconductors and once they are short circuit (and that is the way they go) thats the end of that relay, unless you have the abiblity to test and replace them.
Malcolm
The fuel pump relay is controlled by the the speed limiter on the 124 and 126 and does so by cutting the fuel pump. This info comes from the engine ECU and operates at 4k.
Only by having a voltmeter can you check where everything starts and stops.
Do bear in mind that though there were wiring and fuse holder problems on the 124, the 123 is now getting quite old and wiring used in high current situations can become brittle as can the contacts on the fuse holders.
Running wires direct from the battery can also damage components if you do not remove the relays in question that were or are suppling the voltage or power to the component that you are testing. So by joining a wire from the battery direct to the fuel pump you are effectivly going to blow any other components that switched it off in the first place, and the fault will soon become a multiple job. Most things that come into my workshop, that has been got at by the owner are scrap and unrepairable, I am talking electronics here not cars.
You cant see electricity, nothing moves to the eye, one faulse move on these relays panels blows the semiconductors and once they are short circuit (and that is the way they go) thats the end of that relay, unless you have the abiblity to test and replace them.
Malcolm
