fuel pump relay and other migraines

[Stringer]

Dear all
could anyone give me some details about what to check on a fuel pump relay? Mine was a bit corroded but i brushed it up and now nothing works. Does anyone have any data on what that terminals should read, for example? And which terminals you bridge to make the fuel pump work permanently?
i'm a bit buggered out here in beirut. There are no new ones, but only 'used' ones which i have learnt are mainly 'repaired' ones sold by dubious dealers who just take your money and run.

many thanks

 

[neilrr]

PM'ed

 

[jaymanek]

I think bridging is 30 & 87... its the pins that are directly opposite each other, could be 15 & 87.

This will make the pump run continuously.

 

[Stringer]

i think it's 15 and 87 which are side by side, in fact....but i might be wrong. Have read on many other sites that these would provide power to the pump when ignition is switched on.
any help appreciated

m in beirut

 

[Dec]

30 is always common so bridge 30 and 87 or 87a if you have an 87a.
See here… Single Pole Double Throw (SPDT), Single Pole Single Throw (SPST) Automotive Relays
Disregard the above if you have a number 15 on the relay.

Dec

 

[Stringer]

thanks Dec
can you think of any reason why fuel pump relays would burn? Could it be worn out OVP?

M

 

[Dec]

What type of relay do you have, see here… fuel pump relay 300E 1987 - Google Search
Maybe you could fix it, have you considered opening up the relay to clean up the points or check the circuit board for broken joints.

Dec

 

[Stringer]

Google Image Result for http://i.ebayimg.com/t/OEM-Fuel-Pump-Relay-1986-1987-1988-1989-1990-1991-1992-1993-Mercedes-300-/00/s/MTI4MFg5NjA%3D/%24T2eC16JHJGIE9nnWpiQHBP9LQ(LqrQ~~60_35.JPG

hi, i would have said i have this type, except that mine has only 8 pins in total. Yes, i have taken it apart and had a good inspection of it as i am reasonably competent at repairing electrical equipment, but it seems as clean as a whistle. that's why i wanted some guidance as looking side on at the soldering, it seems that the solder blobs merg into on and other. would it help if i took a photo?
m in beirut

 

[Dec]

Broken joints can be very hard to see, see as an example… N10 Relay, Soldering Repair, Wiper - Indicators & Hazards - Rear Window Demister. - Mercedes-Benz Owners' Forums

You could try plugging it in while it’s out of its shell and wiggling it from side to side, also try closing the points manually with a toothpick/matchstick.

No harm in putting up a picture but if you have a good strong magnifying glass then you will have the best view. Maybe the relay is ok and it’s the socket that the relay plugs into that’s at fault or perhaps the fuel pump is at fault.

Dec

 

[Stringer]

tell me, do you think it's likely that the connecting slots could be corroded and that when the electric fan comes on, then the relay struggles to draw current? When the car heats up beyond 80 degree, it starts to misfire and i can only assume it's cos of this. Also, when i put the electric fan on inside the car, same thing happens. Is there a fuse for the relay, btw?
thanks

 

[Dec]

You have a few issues there that are likely to be related, perhaps the alternator or bad earth to chassis (rust) somewhere, you really need someone with the knowledge and equipment to test the electrics on the car.

There wouldn’t be a fuse for a relay but there would be fuses for a fuel pump and fans etc, you will have to check all the fuses if you have no fuse chart for the car.

Dec

 

[Stringer]

So can anyone help with a fuse chart for starters? Mine is missing!
thank you
m