volvo 850 T5 1996 fuel pump relay problem.

testdrive · Post by **testdrive** » 15 Jan 2010, 09:32

Hello everybody here, im new one here. My english may be bad but i hope all you will understand me. I got that kind of problem now that my car fuel pump relay wont work anymore, i soldered all joints and replaced these two capacitors like readed from this site, so the relay worked about 2 minutes and then it was finished. i bought then a used one, car was working an half an hour and then i drive about 10 km. after that i started car and it was again f****d up. sometimes have power and then not, relay is clicking and so the fuel pressure is also 1-3 bar, still it totally die out. Why relay is burning out, does it got overvoltage or how do say it in english, how should i test it? what voltages or resistances i should check?

FCPEURO · Post by **FCPEURO** » 15 Jan 2010, 13:01

I would check to make sure the correct fuse is being used for the fuel pump first. The fuel pump could be on it's way out, which causes it to use a lot more power and normally, it will blow the fuse or the relay. You can test this by using a jumper wire on the fuel pump relay so that it is always sending power to the pump. Then you will see if the fuse goes or not. If it does, the pump is bad.

testdrive · Post by **testdrive** » 16 Jan 2010, 06:04

i tried this jumper wire , connected these 15 and 87 pins and it was working fine then. but i will check this fuse and pump also

Post by **Ozark Lee** » 16 Jan 2010, 08:56

You may have a bad relay socket in the fuse box if the car runs fine with the jumper wire. It is somewhat rare but it is not unheard of.

...Lee

Klausc · Post by **Klausc** » 16 Jan 2010, 14:15

I would buy a new relay, not a used one.

testdrive · Post by **testdrive** » 17 Jan 2010, 06:30

there s no point to buy new one, because it will also burns out this relay, this used one worked very fine about 10 km, it s about some else problem. tomorrow i will trie to check voltages from fuel pump fuse socket, i think thats the easiest way.

testdrive · Post by **testdrive** » 18 Jan 2010, 05:06

sorry, my bad. if i connect these 15 and 87 pins from relay box, car starts but it still dies after 20 sec. fuel pressure remains about 3 bar. if i try with relay then fuel pressure falls to 2 bar and then zero, because the relay cuts out, with wire it cant, and so then the relay is still OK, fuel pressure is OK with wire,