Fuel Pump Relay

pistonmaster · 07-27-2008, 12:05 PM

Can anyone tell me where the fuel pump relay is located on a 1994 100s wagon 2.8l vin WAUCK84A9RN? I`ve searched both footwells under the hood on the drivers side and have found several relays but none marked fuel pump. My car will crank, but no start. CEL is on. I disconnected the battery for a couple of days, reconnected it and it started and ran well. I shut the car off and no restart. After checking several wiring diagrams and some diagnosing I believe it`s the fuel pump relay...but I can`t find it

ricoblanco · 07-27-2008, 12:14 PM

From the Bentley "The fuel pump relay is located in the fuse/relay panel, on the left side under the instrument panel."

This photo is from my A8, but the pin out and location are identical to the Bentley diagram, so it should look something like this:

Hope this helps!!

pistonmaster · 07-27-2008, 12:46 PM

Awsome! Thank you! Checked it out, and my relay is under the steering wheel as you pointed out.Of course it`s a wierd relay and I don`t have a spare. I ran 12v to the post on the bottom of the connector, and the car started. But once again, after shutting off no restart. I do not have power to the fuel pump fuse, so I still think fuel pump relay. Any other ideas, I`m all out?

ricoblanco · 07-27-2008, 12:58 PM

across B+ (pins 28 & 32)[edit] and ground (pin 34) thereby bypassing the relay and the car started, then yes, the relay is shot.

pistonmaster · 07-27-2008, 01:14 PM

In your picture you`ll see each relay has a terminal below it. They all seem to have b+ with the key on except my fuel pump relay. I gave it b+ from a jumper wire and the car started. my relay has pins 87,87a,86,30, and t(which is a small terminal)the number on the top of the relay is 208. It looks like connecting 87 and 87a to 30 should bypass the relay as well as connecting 86 to t. It seems as everyone of these cars are different. I`m having a lot of trouble getting the correct wiring diagram.

ricoblanco · 07-27-2008, 01:33 PM

Another simple way to test the relay is to measure the voltage across pins 28 & 34 and pins 32 & 34 in the socket while the ignition is on. They both should read ~12V. If not, bad relay.

pistonmaster · 07-27-2008, 01:48 PM

Wow! You`re good! Well I bypassed the fuel pump relay and no start. This all started after the engine was powerwashed. I then drove it later in the day no problems. Parked at home and the next day no start. Hooked up to VAG got a code for cam sensor found no power to cam sensor, crank sensor, ignition pack, or injectors. The wiring diagrams I had here led me to the fuel pump relay. I checked the fuse for the fuel pump it had no power. Now it does and we still have no start? I pulled the battery to charge it, a few days later put it back in and the car started. I need to charge the battery again now at 10.23v dropping to 7.72 while cranking.
Thank you for all of your help!

ricoblanco · 07-27-2008, 02:10 PM

Jairek · 06-10-2010, 04:32 PM

thats what i have wrong with my car i dont have power to the fuse or relay what did you do i needs to know more to get it to run.....

07-27-2008, 12:14 PM	#2
ricoblanco AudiWorld Senior Member 1996 Audi A6 My Garage Join Date: Dec 2007 Posts: 1,199	Here ya go----> From the Bentley "The fuel pump relay is located in the fuse/relay panel, on the left side under the instrument panel." This photo is from my A8, but the pin out and location are identical to the Bentley diagram, so it should look something like this: Hope this helps!! __________________ 98 A8Q Ming Blue pearl effect 96 A6 Casablanca White D2 A8/A8L/S8 FAQ Digest

07-27-2008, 12:46 PM	#3
pistonmaster New Member Garage is empty, add now Join Date: Jul 2008 Posts: 16	Re: Here ya go----> Awsome! Thank you! Checked it out, and my relay is under the steering wheel as you pointed out.Of course it`s a wierd relay and I don`t have a spare. I ran 12v to the post on the bottom of the connector, and the car started. But once again, after shutting off no restart. I do not have power to the fuel pump fuse, so I still think fuel pump relay. Any other ideas, I`m all out?

07-27-2008, 12:58 PM	#4
ricoblanco AudiWorld Senior Member 1996 Audi A6 My Garage Join Date: Dec 2007 Posts: 1,199	You're saying you sent 12V across B+ (pins 28 & 32)[edit] and ground (pin 34) thereby bypassing the relay and the car started, then yes, the relay is shot. __________________ 98 A8Q Ming Blue pearl effect 96 A6 Casablanca White D2 A8/A8L/S8 FAQ Digest

07-27-2008, 01:14 PM	#5
pistonmaster New Member Garage is empty, add now Join Date: Jul 2008 Posts: 16	Re: You're saying you sent 12V In your picture you`ll see each relay has a terminal below it. They all seem to have b+ with the key on except my fuel pump relay. I gave it b+ from a jumper wire and the car started. my relay has pins 87,87a,86,30, and t(which is a small terminal)the number on the top of the relay is 208. It looks like connecting 87 and 87a to 30 should bypass the relay as well as connecting 86 to t. It seems as everyone of these cars are different. I`m having a lot of trouble getting the correct wiring diagram.

07-27-2008, 01:33 PM	#6
ricoblanco AudiWorld Senior Member 1996 Audi A6 My Garage Join Date: Dec 2007 Posts: 1,199	Wiring diagram, eh? Ask and ye shall receive ----> Another simple way to test the relay is to measure the voltage across pins 28 & 34 and pins 32 & 34 in the socket while the ignition is on. They both should read ~12V. If not, bad relay. __________________ 98 A8Q Ming Blue pearl effect 96 A6 Casablanca White D2 A8/A8L/S8 FAQ Digest

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07-27-2008, 01:48 PM	#7
pistonmaster New Member Garage is empty, add now Join Date: Jul 2008 Posts: 16	Re: Wiring diagram, eh? Ask and ye shall receive ----> Wow! You`re good! Well I bypassed the fuel pump relay and no start. This all started after the engine was powerwashed. I then drove it later in the day no problems. Parked at home and the next day no start. Hooked up to VAG got a code for cam sensor found no power to cam sensor, crank sensor, ignition pack, or injectors. The wiring diagrams I had here led me to the fuel pump relay. I checked the fuse for the fuel pump it had no power. Now it does and we still have no start? I pulled the battery to charge it, a few days later put it back in and the car started. I need to charge the battery again now at 10.23v dropping to 7.72 while cranking. Thank you for all of your help!

07-27-2008, 02:10 PM	#8
ricoblanco AudiWorld Senior Member 1996 Audi A6 My Garage Join Date: Dec 2007 Posts: 1,199	You're welcome! :-) __________________ 98 A8Q Ming Blue pearl effect 96 A6 Casablanca White D2 A8/A8L/S8 FAQ Digest

06-10-2010, 04:32 PM	#9
Jairek AudiWorld Member 1990 Audi Quattro Join Date: Jan 2010 Location: Colorado Posts: 205	thats what i have wrong with my car i dont have power to the fuse or relay what did you do i needs to know more to get it to run..... __________________ 1990 V8 Mostly Stock For Now

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