1974 wiring and fuel problems, need answer to the wiwing of fuel pump from relay board Options

[Matthewk]

Hello, I've been working on a 1974 914 for the past year. Ive rebuilt the motor since the last owner overheated it somehow (no compression). Ive put the motor back in and I cannot seem to remember where any of the small female ground connectors go from the wiring harness. Like the many different small ones in the transmission harness that goes into the engine bay. And the two near the distributor. I remember there being a ground connection under the intake but I dont know which ones go there. Ive been trying to read wiring diagram but I cant understand it what so ever because nothing is labeled. So I'm just guessing reading it.

My other question is, what do I do about the fuel pump not working. If you put power externally it works, but from the relay board it just has no power past it. The power supply relay clicks, but fuel pump does not. There was power to the fuel pump relay pins a couple days ago now there isn't. Maybe I'm just tweaking out. Last owner has a whole bunch of fuel pump related things highlighted in the book he gave me. My brother read that the relay board could go bad but I doubt it.

In another post, I read that you need to switch the 25 amp fuse for an 18. It solved someone else problem of blowing relays. Ive swapped relays around and they work in other spots. So it isn't bad relays.

Hopefully someone understand what I'm asking and has the solutions for it.

thx

[JeffBowlsby]

Help us help you!

Start by telling us what engine you have, and is everything stock, or are there mods? Also photos of the harness(es) in the car, you holding the wires you need to connect (to depict the context) would be helpful. If you will number the wires even better so we can say “wire 3 goes to the ground connection at the rear top of engine case” etc.

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[Matthewk]

So, its a fully stock 1974 1.8L

https://ik.imagekit.io/bhptmszid/IMG_1928.j...t=1758928645823

trying different ways to add an image but isn't working. so here's an image link.

the white wire (#1) I'm holding is from the main harness, close to the computer.
The two black wires (#2) I'm holding go into one connection.
then there's a green and brown (#3) , brown (#4) , black and red (#5)

[JeffBowlsby]

This diagram should answer all you questions: https://bowlsby.net/914/WiringHarnesses/doc...74-75_L-Jet.pdf

If not let me know.

Adding photos is easy, if you know rules. http://www.914world.com/bbs2/index.php?showtopic=13637

[Matthewk]

This diagram should answer all you questions: https://bowlsby.net/914/WiringHarnesses/doc...74-75_L-Jet.pdf

If not let me know.

Adding photos is easy, if you know rules. http://www.914world.com/bbs2/index.php?showtopic=13637

oh thx. can you send me a diagram for main harness too? Thank you!

[JeffBowlsby]

All are here:

https://bowlsby.net/914/WiringHarnesses/#ReferenceLibrary

[wonkipop]

Hello, I've been working on a 1974 914 for the past year. Ive rebuilt the motor since the last owner overheated it somehow (no compression). Ive put the motor back in and I cannot seem to remember where any of the small female ground connectors go from the wiring harness. Like the many different small ones in the transmission harness that goes into the engine bay. And the two near the distributor. I remember there being a ground connection under the intake but I dont know which ones go there. Ive been trying to read wiring diagram but I cant understand it what so ever because nothing is labeled. So I'm just guessing reading it.

My other question is, what do I do about the fuel pump not working. If you put power externally it works, but from the relay board it just has no power past it. The power supply relay clicks, but fuel pump does not. There was power to the fuel pump relay pins a couple days ago now there isn't. Maybe I'm just tweaking out. Last owner has a whole bunch of fuel pump related things highlighted in the book he gave me. My brother read that the relay board could go bad but I doubt it.

In another post, I read that you need to switch the 25 amp fuse for an 18. It solved someone else problem of blowing relays. Ive swapped relays around and they work in other spots. So it isn't bad relays.

Hopefully someone understand what I'm asking and has the solutions for it.

thx

in a 1.8 fuel pump does not run with ignition on.
runs when key goes to crank position.
after the engine fires the AFM sends the signal to the ECU via the dual relay (located under the battery box in the side of battery box support) and the AFM is telling the fuel pump to run. if engine stops running fuel pump stops running. there is hardly anything on the relay board on lhs of engine bay with a 1.8 L jet. they are not like the D jet cars.

[fiacra]

Hello, I've been working on a 1974 914 for the past year. Ive rebuilt the motor since the last owner overheated it somehow (no compression). Ive put the motor back in and I cannot seem to remember where any of the small female ground connectors go from the wiring harness. Like the many different small ones in the transmission harness that goes into the engine bay. And the two near the distributor. I remember there being a ground connection under the intake but I dont know which ones go there. Ive been trying to read wiring diagram but I cant understand it what so ever because nothing is labeled. So I'm just guessing reading it.

My other question is, what do I do about the fuel pump not working. If you put power externally it works, but from the relay board it just has no power past it. The power supply relay clicks, but fuel pump does not. There was power to the fuel pump relay pins a couple days ago now there isn't. Maybe I'm just tweaking out. Last owner has a whole bunch of fuel pump related things highlighted in the book he gave me. My brother read that the relay board could go bad but I doubt it.

In another post, I read that you need to switch the 25 amp fuse for an 18. It solved someone else problem of blowing relays. Ive swapped relays around and they work in other spots. So it isn't bad relays.

Hopefully someone understand what I'm asking and has the solutions for it.

thx

If it is of any help I have a fully stock, unmolested 1975 1.8 and if you need pictures of any specific areas of the engine to see how things are put together, and potentially where wires go, I'm happy to provide them. Just let me know. Jeff has already pointed you to his website, and there are tons of resources there.

[wonkipop]

and if you are looking for a really good wiring diagram in color go here.

http://p914-6info.net/Manuals.htm

you can download a copy of the factory workshop manual.
the electrical chapter has the wiring diagrams for all the cars in different forms.
will let you track and trace the quite different wiring for the fuel injection in the 1.8s.

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i had this photo lying around from another topic.
dual relay is the gizmo doing a lot of the work controlling the f p.
if its an original d r it will be silver in color.
later update replacement d r is black plastic.

[wonkipop]

forgot to mention.
you can test the fuel pump is running by pushing the flap in the AFM mounted to the air cleaner with the ignition to the on position. it should run.

easiest way is to unclip the top of the air cleaner, hold it up in the air a bit and push the flap with your fingers. gently. or use a screwdriver to push it if your fingers cant get in there far enough. (IMG:style_emoticons/default/beerchug.gif)


as to relay board. 1.8s only have one relay in there. for the heater blower fan.
the other sockets are left empty.
fuse = 18 amp normally. (25 amp if you have a heated rear window). i dont know much about those, no heated rear window in mine.
dual relay for L Jet under battery replaces all the relays normally on the board for D jet cars.

[Matthewk]

Hello, I've been working on a 1974 914 for the past year. Ive rebuilt the motor since the last owner overheated it somehow (no compression). Ive put the motor back in and I cannot seem to remember where any of the small female ground connectors go from the wiring harness. Like the many different small ones in the transmission harness that goes into the engine bay. And the two near the distributor. I remember there being a ground connection under the intake but I dont know which ones go there. Ive been trying to read wiring diagram but I cant understand it what so ever because nothing is labeled. So I'm just guessing reading it.

My other question is, what do I do about the fuel pump not working. If you put power externally it works, but from the relay board it just has no power past it. The power supply relay clicks, but fuel pump does not. There was power to the fuel pump relay pins a couple days ago now there isn't. Maybe I'm just tweaking out. Last owner has a whole bunch of fuel pump related things highlighted in the book he gave me. My brother read that the relay board could go bad but I doubt it.

In another post, I read that you need to switch the 25 amp fuse for an 18. It solved someone else problem of blowing relays. Ive swapped relays around and they work in other spots. So it isn't bad relays.

Hopefully someone understand what I'm asking and has the solutions for it.

thx

If it is of any help I have a fully stock, unmolested 1975 1.8 and if you need pictures of any specific areas of the engine to see how things are put together, and potentially where wires go, I'm happy to provide them. Just let me know. Jeff has already pointed you to his website, and there are tons of resources there.

heya, Im responding after who knows how long cause of school and other things. Yea I wouldn't mind a pic of mainly the harness that goes to the ignition coil. Im trying to wire up the engine bay since i put the motor back in, and it seems like there was a crackhead before me that flipped everything on its head and nothing is in place..
Ignition coil is the last thing before vacuum hoses.

[Artfrombama]

Hello, I've been working on a 1974 914 for the past year. Ive rebuilt the motor since the last owner overheated it somehow (no compression). Ive put the motor back in and I cannot seem to remember where any of the small female ground connectors go from the wiring harness. Like the many different small ones in the transmission harness that goes into the engine bay. And the two near the distributor. I remember there being a ground connection under the intake but I dont know which ones go there. Ive been trying to read wiring diagram but I cant understand it what so ever because nothing is labeled. So I'm just guessing reading it.

My other question is, what do I do about the fuel pump not working. If you put power externally it works, but from the relay board it just has no power past it. The power supply relay clicks, but fuel pump does not. There was power to the fuel pump relay pins a couple days ago now there isn't. Maybe I'm just tweaking out. Last owner has a whole bunch of fuel pump related things highlighted in the book he gave me. My brother read that the relay board could go bad but I doubt it.

In another post, I read that you need to switch the 25 amp fuse for an 18. It solved someone else problem of blowing relays. Ive swapped relays around and they work in other spots. So it isn't bad relays.

Hopefully someone understand what I'm asking and has the solutions for it.

thx

If it is of any help I have a fully stock, unmolested 1975 1.8 and if you need pictures of any specific areas of the engine to see how things are put together, and potentially where wires go, I'm happy to provide them. Just let me know. Jeff has already pointed you to his website, and there are tons of resources there.

heya, Im responding after who knows how long cause of school and other things. Yea I wouldn't mind a pic of mainly the harness that goes to the ignition coil. Im trying to wire up the engine bay since i put the motor back in, and it seems like there was a crackhead before me that flipped everything on its head and nothing is in place..
Ignition coil is the last thing before vacuum hoses.

[fiacra]

heya, Im responding after who knows how long cause of school and other things. Yea I wouldn't mind a pic of mainly the harness that goes to the ignition coil. Im trying to wire up the engine bay since i put the motor back in, and it seems like there was a crackhead before me that flipped everything on its head and nothing is in place..
Ignition coil is the last thing before vacuum hoses.

Just seeing this now. If you tag someone in a post they will get a notification that you were trying to get their attention. Like this: @Matthewk

Here's a few photos. Tried to follow the wiring back from the coil. Maybe not the best sequence trying to do it one handed, holding a light in the other hand, and pulling back hoses... If you need anything else, or better pics, let me know.

[Matthewk]

forgot to mention.
you can test the fuel pump is running by pushing the flap in the AFM mounted to the air cleaner with the ignition to the on position. it should run.

easiest way is to unclip the top of the air cleaner, hold it up in the air a bit and push the flap with your fingers. gently. or use a screwdriver to push it if your fingers cant get in there far enough. (IMG:style_emoticons/default/beerchug.gif)


as to relay board. 1.8s only have one relay in there. for the heater blower fan.
the other sockets are left empty.
fuse = 18 amp normally. (25 amp if you have a heated rear window). i dont know much about those, no heated rear window in mine.
dual relay for L Jet under battery replaces all the relays normally on the board for D jet cars.

yea, so i tried that and nothing (IMG:style_emoticons/default/smile.gif) there was another cpu in the trunk so i swapped it out and still nothing. I tested the air filter box with multimeter in diode mode and there is signal when flap is pushed down. Tested fuel pump with external power and it works just fine. I tested harness when i pulled motor out a while ago and all wires are good. So im really at a loss at what the problem could be. Maybe a ground somewhere? or some hidden wires that aren't connected maybe.

Last owner had same problem. Fuel pump was cutting out on him when he was driving on the free way he said. Even he couldn't figure it out. He did replace fuel pump relay many times but was only a temp fix. I did buy new relays but still nothing. Eventually he gave up and forgot about the car.

[Matthewk]

heya, Im responding after who knows how long cause of school and other things. Yea I wouldn't mind a pic of mainly the harness that goes to the ignition coil. Im trying to wire up the engine bay since i put the motor back in, and it seems like there was a crackhead before me that flipped everything on its head and nothing is in place..
Ignition coil is the last thing before vacuum hoses.

Just seeing this now. If you tag someone in a post they will get a notification that you were trying to get their attention. Like this: @Matthewk

Here's a few photos. Tried to follow the wiring back from the coil. Maybe not the best sequence trying to do it one handed, holding a light in the other hand, and pulling back hoses... If you need anything else, or better pics, let me know.

thx! Can you send pics of the main wire harness? Lat owner cut some things for some reason so idk where they go. The part that was cut has 3 wires in one sleeve. and ends near coil.

Cant seem to relate diagram to my car. Will look back on videos i took as well.

[Matthewk]

nvm guys. my brain turned on and everything works now. I just need a new starter. Starter from china has shaft that wobble like crazy and jumps around. Do you know where to get a good one?