# Fuel pump relay clicking with ignition on



## zero. (Aug 14, 2001)

This is on an AEG. When I turn the key on, the fuel pump relay starts clicking rapidly and keeps priming the fuel pump. The throttle body also clicks at the same time. The car currently runs fine and the clicking stops once started. I gave the car to my girlfriend and she's been driving it. A couple weeks ago she said the speedometer stopped working on the way back from a store, but it's been working fine since. I tried pulling codes, but it currently will not connect to the engine module but finds the transmission fine. 

I've tried known working OEM spare fuel pump relays and they all click too. In searching I've seen others have similar issues but no definitive answers other than maybe a bad ECU ground, crank sensor, weak battery, etc. I'm leaning towards a bad crank sensor because of the speedo cutting out and have a new one on the way, but would that cause issues connecting to the engine module with VCDS? I've had no problems connecting in the past and I've never had a bad crank sensor cause VCDS to not connect on older models.


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## zero. (Aug 14, 2001)

I tried a new crank sensor today when changing the oil and relay is still clicking when ignition is on. Still drives fine. Anyone else with an AEG ever experience this and know the fix or have a wiring diagram that shows the fuel pump relay?


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## zero. (Aug 14, 2001)

Tried a new ignition switch. Still no luck. I'm starting to think it's a bad ground, ECU, or something with the alarm system. Still drives fine. Is there any way to completely disable the alarm on these cars like how you can add a jumper wire on a Mk3?


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## billymade (Jan 29, 2008)

What year is your new beetle? The immobilizer, started with the 2000 model year; the immobilizer can be deleted from the ecu. One vendor who does this; is ian from reflect tuning, he offers this service here: https://squareup.com/store/reflecttuning


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## zero. (Aug 14, 2001)

1998. It has a factory alarm. I was hoping I could bypass it like a Mk3 to rule it out. Thinking about it now, I'm not even sure if it ever actually arms because it has hood pins to pass inspection and no microswitch hooked up to the hood latch. It's had the hood pins for over 6 months though and the relay clicking didn't start until recently.

BTW I also posted on the NB forums. I cleaned the TB last night and no difference. Don't think it's related now since the relay was still clicking with everything disconnected.


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## zero. (Aug 14, 2001)

Little over a year later...Clicking slowed down to about 1 click every 10 seconds instead of rapid. It progressed to hard cold starts and throttle hesitation on initial startup. Tried coolant temp sensor but didn't help. I was trying to perform a throttle body adaptation and kept getting communication errors. When the relay would click it seemed to be killing power to ECU because the CEL would go off and come back on. Went to clean grounds at ECU but ended up being corroded pins at ECU/harness as I had some water and a rodent nest under dash covers. Cleaned up the ECU and harness and it's been fine since :thumbup:


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## billymade (Jan 29, 2008)

Sounds good! As time goes on, after 15-20 years; it seems we are seeing more water ingress, corrosion and rodents, damaging our electrical systems! :facepalm: Glad, you finally; got it fixed!  eace: :wave:


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