I have been following the directions in other posts to wire my car for carbs with a low pressure pump under the tank. In front I have a black/red wire and brown for ground which is expected. My number 13 pin on the 14 pin connector is green rather than black with red. I can't find a diagram of a '75 relay board and it's not in my manual. The previous owner had blue a jumper wire connected as shown in the photo. Is this arrangement right for this year when running carbs?
Attached image(s)
The blue jumper wire activates the fuel pump without the efi if I remember correctly.
It looks like pin 3 is connected to pin 4.
Pin 3 is the fuel pump relay pin should be connected to ground to energize the relay.
Pin 4 is connects to the starter.
With that connection, the fuel pump will run unless the starter is engaged. Not sure why it's connected like that.
Attached thumbnail(s)
Yes the PO had 3 and 4 connected. I’m not getting power when I ground 3 and Pin 13 is not showing 12v when the key is on. Seems like something is different on the ‘75 car?
I found a Bowlsby photo that shows the '75 with a greeen wire (pin 13) attached to the black/red wire under the dash being stock. I'm wondering if someone cut the green wire under my dash which would explain not having power at 13. I'll check that today.
It looks like the jumper from 3 to 4 was carrying power to the fuel pump relay because one of those tabs is connected to pin 1 (yellow wire) on the 14 pin connector.
Thank you for the reminder to disconnect the battery.
I have power on both sides of the fuse
Tested the relays and they all switch when power is applied
Confirmed that the ‘75 has a green wire from pin 13 and changes to a black and red wire under the dash to connect to the fuel pump, this must be specific to ‘75 and ‘76 cars?
Maybe I have a problem with 85 or 86 on the power supply relay which is not sending signal to the fuel pump relay switch?
Attached thumbnail(s)
Well it looks like fuel pump week. I wish I had something to contribute.
Spoke is working overtime.. Hopefully we will both have things sorted soon.
Good luck mtndawg, I am following!
John
Had the relay board out testing everything I could think should have continuity and everything checked out along with getting 12 volts in all the right locations. I put it all back together to test for voltage at the pump. When I turned the key it went on! I don’t know what the problem was. Moving forward for now.
Attached thumbnail(s)
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)