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currently sitting at the side of a road. .
bi22le - 15/7/12 at 08:17 AM

Because my car has decided to start blowing fuel pump fuses.
Seems to be a dead short as its blowing 30A.

Fuel pumps works so is not seized.

Jiggled all of the wiring i think it could be to try and trace it.

My brother has gone to fetch more fuses!!

Ben_Copeland - 15/7/12 at 08:35 AM

I doubt more fuses will help...

Its either a short in the wiring, or your pump has gone.

owelly - 15/7/12 at 08:38 AM

If you have a relay in the fuel pump circuit, try swapping it with another one. I found some of my relays were full of water...

steve m - 15/7/12 at 08:55 AM

what about using a wire from a rear light to power the pump, and if that works you know that the original feed wire has earthed out somewhere
at least that will get you home

putting more fuses in, will just end in miserey, and probably end up like Hicosts car, all burnt out, due an electrical fire

bi22le - 15/7/12 at 09:01 AM

Im just going to keep pluging fuses in until i get back home. Im only about a mile from my house.

I have just checked the relays, good idea, they Dont show any signs of water.

If my pump has issues would it keep working for ages then suddenly start shorting out?

MakeEverything - 15/7/12 at 09:18 AM

quote:
Originally posted by bi22le

If my pump has issues would it keep working for ages then suddenly start shorting out?


It would if the motor inside is breaking down and overheating - Rather, it wont be shorting out, just high impedance.


ETA: have you checked your fuel filters and that the fuel tank isnt under vacuum?



[Edited on 15-7-12 by MakeEverything]

bi22le - 15/7/12 at 09:30 AM

Not checked fuel filters and i have a breather on the tank so will check that to.

I may just take tge fuel pump off and give it a tap and rattle. See if i can cause it to permanently fail!

Ill also swap the relays n run a separate supply to the pump after the relay to rule out shortages.

Im home now but should be at the cafe with skcc lot.

steve m - 15/7/12 at 09:51 AM

Before condeming the pump, surely you need to check the wiring for a short first ?

wilkingj - 15/7/12 at 10:25 AM

quote:
Originally posted by steve m
Before condeming the pump, surely you need to check the wiring for a short first ?


I agree... also there may not be a full short curcuit. It could / should be a vey low resistance to blow a 30A fuse, almost certainly a short circuit, but may not be.

I would also check the wiring for chafing, and rubbing through. Especially around corners, and any saddle clamps (especially if not insulated clamps)
Spend a GOODLY amount of time, just looking it over and inspecting all the wiring for the above.

Finally, Loosen the battery Earth terminal bolt first, so that you can pull it off quickly if anything starts to smoke! You can waste vital seconds finding the right spanner, expecially if you garage is as chaotic as mine! Oh... and keep a fire extinguisher handy. You know you have a problem, prepare properly for the work! It could save you a lot of heartache, or even an insurance claim.

Good luck.

Macbeast - 15/7/12 at 11:53 AM

My wife's car ( Focus ) would blow petrol pump fuses only after trying to restart after a short halt on a long journey. I assume pump overheated with no petrol going through it and partially jammed leading to high start current being drawn. New petrol pump seems to have cured it.

bi22le - 15/7/12 at 11:58 AM

I think i have found the problem. Although visual inspection gave nothing away i think its the relay.

I checked some stuff and I swapped the relays about and then went for a test drive. I noticed my car was getting mega hot. Its never had cooling issues. Pulled over and the fuse for the fan had gone. Again a new symptom. Changed the relay and now fan fuse and fuel pump fuses seem good. The relay was really hot which was another give away. Im currently an hour or so from home. Lets see if i can make it back!

So far owelly wins the pat on the back for suggesting relays.

Regarding shorts and small draws, the fuses are blowing spectacularly so its more short then draw. Also i have checked the wiring for rubbing a wiggled everything. At time the fuse was blowing with no movement at all from the car but turn ignition on and off. Problem seemed to disappear for an unknown amount of time.

Ill report back in about an hour, i hope from my front room with a cup of tea!

bi22le - 15/7/12 at 01:56 PM

Well i am home. sold on the idea its a dodgy relay.

Thanks for everybody help and thoughts.

owelly - 15/7/12 at 02:00 PM

Whilst I'm on a roll......just check the fan isn't seized. It could be that overheating the relay/popping the fuses.