No power to the fuel pump relay
Discussion
A little bit of help required please. I bit the bullet yesterday and gave the car a wash.
However on trying to start it today, I can't hear the fuel pump priming, and the car won't fire up, it just turns over. I've metered the 20a fuse, and it's ok, and I've connected the brown relay to a 12v source and it works perfectly.
However, when it's back in situ in the car, it doesn't appear to be getting any voltage to it.
Silver key is ok.
Any ideas please ?
If it's alarm/inmobiliser related, please email me.
Ta
Russ
However on trying to start it today, I can't hear the fuel pump priming, and the car won't fire up, it just turns over. I've metered the 20a fuse, and it's ok, and I've connected the brown relay to a 12v source and it works perfectly.
However, when it's back in situ in the car, it doesn't appear to be getting any voltage to it.
Silver key is ok.
Any ideas please ?
If it's alarm/inmobiliser related, please email me.
Ta
Russ
Edited by RUSSELLM on Monday 14th January 09:26
It cuts the power to the fuel pump and the ecu ( which controls the fuel pump ) .You could bridge the terminals in the fuse board where the relay sits to see if you have lost the signal or the main power supply . If that does not work you should put a live to the pump feed wire incase it is your pump seized ( not unusual )
Thanks.
I've removed the brown relay, and it has a small diagram on it.
It shows the coil pins to fire the relay, I'm presuming there is a permanent O volt negative on one of these pins, and the ignition throws a 12V positive to the other pin, to make the relay click. (providing the immobiliser lets the power through)
It then shows a common pin that connects to two other pins when the relay has been fired (double pole relay)......Does any one know if that common pin is pos or neg ?
Also, is there a permanent pos or neg anywhere in that fuse box, that you can use for testing purposes.
I know I can have a set of leads hanging off the battery, but I was wondering if anyone knew of a better way
I've removed the brown relay, and it has a small diagram on it.
It shows the coil pins to fire the relay, I'm presuming there is a permanent O volt negative on one of these pins, and the ignition throws a 12V positive to the other pin, to make the relay click. (providing the immobiliser lets the power through)
It then shows a common pin that connects to two other pins when the relay has been fired (double pole relay)......Does any one know if that common pin is pos or neg ?
Also, is there a permanent pos or neg anywhere in that fuse box, that you can use for testing purposes.
I know I can have a set of leads hanging off the battery, but I was wondering if anyone knew of a better way
plasticman said:
It cuts the power to the fuel pump and the ecu ( which controls the fuel pump )
Hadn't thought about the ECU.I've checked the fuel pump fuse (No.20), but the ECU suggestion also means it could be fuse no. 12 (injectors, engine ECU, immobiliser) or fuse no 14 (engine ECU back up, steering ECU supress)
I think I'll check the lot when I get home
It was dark last night, and that sensor on the fuel tank was on pretty tight, to a point where I felt I'd break it trying to get it off.
All the fuses are intact.
I've had four symptoms recently, any one of which may be connected to the fault.
1) The top of the rear window is leaking, in fact last night the drivers side of the boot had water in it.
2) The battery light has been on for the first few minutes when driving, but that's probably a failing 100A fuse
3)On the last couple of drives, I could hear A slight electrical screaching/whining noise from the back of the car.
4) Recently the drivers door & boot wouldn't open, but that's cleared itself.
I'm fairly confident the immobiler's got wet.
It's dark when I get home, but on Saturday I'll try putting a pos on to the fuse for the fuel pump, and see if I can get the thing going.
Fairly sure this is An AA/TVR Power job
All the fuses are intact.
I've had four symptoms recently, any one of which may be connected to the fault.
1) The top of the rear window is leaking, in fact last night the drivers side of the boot had water in it.
2) The battery light has been on for the first few minutes when driving, but that's probably a failing 100A fuse
3)On the last couple of drives, I could hear A slight electrical screaching/whining noise from the back of the car.
4) Recently the drivers door & boot wouldn't open, but that's cleared itself.
I'm fairly confident the immobiler's got wet.
It's dark when I get home, but on Saturday I'll try putting a pos on to the fuse for the fuel pump, and see if I can get the thing going.
Fairly sure this is An AA/TVR Power job
Thought I'd post my answer to this, in case anyone ever stumbles across it on a search.
OK.. Normally you turn the alarm off, get in the car, press the ignition button, and the ignition comes on, fuel pump primes etc.
However if you take more than 15 seconds, the immobiliser rearms (red light starts flashing) and you have to press your fob again to turn it off and get the fuel pump to prime.
I noticed this morning, that I turned the alarm off, got in the car, pressed the ignition, and the immobiliser rearmed (red light started flashing).....Even though the 15 seconds hadn't elapsed. I pressed my fob, immobiliser turned off, but the fuel pump still wouldn't prime.
So I'm guessing this is an alarm related problem.
Got out of the car and rearmed the alarm, but with my finger on the fob for 16 seconds (as per another thread). Turned the alarm off with another 16 second press.
And hey presto, it's working properly again
Battery's now dead from me trying to turn it over last week, but when I get back from work with some leads, I'm confident she'll fire up
OK.. Normally you turn the alarm off, get in the car, press the ignition button, and the ignition comes on, fuel pump primes etc.
However if you take more than 15 seconds, the immobiliser rearms (red light starts flashing) and you have to press your fob again to turn it off and get the fuel pump to prime.
I noticed this morning, that I turned the alarm off, got in the car, pressed the ignition, and the immobiliser rearmed (red light started flashing).....Even though the 15 seconds hadn't elapsed. I pressed my fob, immobiliser turned off, but the fuel pump still wouldn't prime.
So I'm guessing this is an alarm related problem.
Got out of the car and rearmed the alarm, but with my finger on the fob for 16 seconds (as per another thread). Turned the alarm off with another 16 second press.
And hey presto, it's working properly again
Battery's now dead from me trying to turn it over last week, but when I get back from work with some leads, I'm confident she'll fire up
Only worked as a temporary fix
Apparently the immobiliser has two circuits. One for the ignition (solved by the "long press" farce) the other circuit being the feed to the fuel pump.
The rear screen had let water in, which had created a pool of water behind the helmet holder, resulting in the immobiliser & connections corroding.
Ended up ripping out the TVR immobiliser out & putting another make in.
HTH
Eta... You've most likely got a duff/failing immobiliser
Apparently the immobiliser has two circuits. One for the ignition (solved by the "long press" farce) the other circuit being the feed to the fuel pump.
The rear screen had let water in, which had created a pool of water behind the helmet holder, resulting in the immobiliser & connections corroding.
Ended up ripping out the TVR immobiliser out & putting another make in.
HTH
Eta... You've most likely got a duff/failing immobiliser
Edited by RUSSELLM on Friday 20th June 19:36
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