[T3] Fuel Pump Relay - 69 Fastback
schillertim at comcast.net
Fri Jul 9 10:48:24 PDT 2021
I will follow the ground and check the fuse
I did hook a reliable 12V to the red wire going to pump. Pump buzzes loud and clear.
I had purchased 2 relays and swapped just in case one was bad, but same results
Sent from my iPhone
> On Jul 9, 2021, at 10:35 AM, Jim Adney <jadney at vwtype3.org> wrote:
> 86 should get 12 V from the main relay as long as the key is ON.
> 85 gets grounded by the ECU for ~1 seconds unless the engine is turning
> over. If the engine is turning over (or running) the ECU keeps this terminal
> 85 & 86 are the connections to the relay coil, so the relay should close and
> send 12 V to terminal 87 for ~1 second after the key is turned ON or as long
> as the engine is turning over or running.
> Check the fuel pump fuse carefully. Sometimes the fusable link can break
> but still look good.
> 87 is the power source for the fuel pump. It should have 12 V on it as long as
> there is 12 V from 85 to 86. Follow that red wire to the firewall and find a
> brown wire that comes along with the red wire from the pump. The brown
> wire is the fuel pump ground.
> It can be helpful to get someone to listen down by the RF tire, to see if they
> hear the fuel pump buzz. It should always buzz for that first ~1 second.
> On 68-70 cars that brown wire goes to ground via a rather torturous route. I
> make a very simple $10 kit to greatly improve the reliability of that ground,
> but I need your VIN to get you the right kit.
> If you're not getting full voltage from the pump relay, try a small jumper wire
> from a reliable 12 V source to the red wire to the pump.
> There are lots of possibilities for why your car won't start. Check to see if the
> pump is running. If it's not, continue checking out its power source, both 12 V
> and ground. If those are okay, the problem could still be in the pump. I
> rebuild them, but that starts to cost real money.
> Stick with this and keep us in the loop. We all want to see you get this
> running nicely.
>> On 8 Jul 2021 at 22:07, Tim Schiller wrote:
>> Car had been running well until it would not start. It initially started but sputtered, then nothing. I did not try to start again for about 4 month´s. I tried again, it started, I washed, waxed and went to fill up before a show. After waiting 3 1/2 hours for a tow at the gas station, it hasn´t started since. I tell this story only for background leading up to my question.
>> Tested Fuel Pump Relay and no power to the 87 pin for the 1-1 1/2 seconds when key is turned. The 86 pin has 12V when key turned and 12V to power relay under back seat.
>> I tested fuel pump directly and it appears to work fine when it has 12V
>> Replaced Furl Pump Relay and I get power to the 87 pin for the 1 - 1 1/2 seconds. Car still doesn´t start. Check voltage to 87 pin again and I´m only getting about 5V for the 1-1 1/2 seconds. Should I be getting 12V? If I should have 12V, suggestions on why I not and what I should check next?
>> Any help is appreciated
>> Sent from my iPhone
>> VWType3.Org mailing list - type3 at vwtype3.org
>> To unsubscribe or change subscription options, visit:
>> If you need more help, contact: gregm at vwtype3.org
> Jim Adney, jadney at vwtype3.org
> Madison, Wisconsin, USA
> VWType3.Org mailing list - type3 at vwtype3.org
> To unsubscribe or change subscription options, visit:
> If you need more help, contact: gregm at vwtype3.org
More information about the type3-vwtype3.org