Fuel Pump Issues... AGAIN

[Zed Head]

If you're working with the pins on the bottom of the relay you might consider just taking the relay apart and watching what happens.  With the top off you can easily see which wires actuate the relay coils.  Several of us have found fried/burned coils inside our relays boxes.  I have a picture of one that was full of rust.  

Just pry the tabs back that hold the top on and pop it off.

[superlen]

Good idea, Zed!

Moozie,

Remember we are testing that the pin/wire W72 right at the relay is properly grounded. There shouldn't be any voltage there ever! When you say "I'm not reading anything off of W72" it sounds like you're looking for voltage there. Maybe I'm interpreting wrong... The multimeter should be in volts mode, the Red lead on +12v battery, and the Black lead on W72. When connected this way, we are using the black lead to test if something is grounded. Anything you touch with the black lead that is ground should make the meter read +12v. Touch black to battery negative, read 12V, touch to car frame, read 12v, touch W72, read 12V.   If the meter doesn't read 12V when it's connected this way then W72 is not grounded and your FIR won't operate as it has no ground reference. This would definitely be a problem!

Note: You could also measure the resistance from W72 to ground, it should be 0 ohms (or very near). If you follow the wire (W72) from the FIR it should travel over to the frame somewhere and be grounded with a ring terminal along with some other wires. A visual inspection may turn up some corrosion at that connection or perhaps its just completely unconnected/broke/cut wire. I would take it loose and clean the ground connection even if it looks good just to be safe.

Len

[moozieman]

8 hours ago, superlen said:

Good idea, Zed!

Moozie,

Remember we are testing that the pin/wire W72 right at the relay is properly grounded. There shouldn't be any voltage there ever! When you say "I'm not reading anything off of W72" it sounds like you're looking for voltage there. Maybe I'm interpreting wrong... The multimeter should be in volts mode, the Red lead on +12v battery, and the Black lead on W72. When connected this way, we are using the black lead to test if something is grounded. Anything you touch with the black lead that is ground should make the meter read +12v. Touch black to battery negative, read 12V, touch to car frame, read 12v, touch W72, read 12V.   If the meter doesn't read 12V when it's connected this way then W72 is not grounded and your FIR won't operate as it has no ground reference. This would definitely be a problem!

Note: You could also measure the resistance from W72 to ground, it should be 0 ohms (or very near). If you follow the wire (W72) from the FIR it should travel over to the frame somewhere and be grounded with a ring terminal along with some other wires. A visual inspection may turn up some corrosion at that connection or perhaps its just completely unconnected/broke/cut wire. I would take it loose and clean the ground connection even if it looks good just to be safe.

Len

Okay I'll look into it again. I appreciate your help and your patience. What I had done was touched the red lead to the positive battery terminal and the black lead to W72 and read 0V.

[moozieman]

12 hours ago, Zed Head said:

If you're working with the pins on the bottom of the relay you might consider just taking the relay apart and watching what happens.  With the top off you can easily see which wires actuate the relay coils.  Several of us have found fried/burned coils inside our relays boxes.  I have a picture of one that was full of rust.  

Just pry the tabs back that hold the top on and pop it off.

Had trouble prying those tabs open. Should i just use a screwdriver? I was concerned about all the old brittle plastic just crumpling.

[superlen]

53 minutes ago, moozieman said:

Okay I'll look into it again. I appreciate your help and your patience. What I had done was touched the red lead to the positive battery terminal and the black lead to W72 and read 0V.

Great!!...you've found a major problem. W72 isn't grounded to the frame like it is supposed to be. There's no way the FIR can work without W72 making a connection to ground.

Len

[moozieman]

7 minutes ago, superlen said:

Great!!...you've found a major problem. W72 isn't grounded to the frame like it is supposed to be. There's no way the FIR can work without W72 making a connection to ground.

Len

So how do I go about finding this disconnection?

[superlen]

Physically follow wire 72 from the FIR to where it is supposed to connect to ground. It should run to a ring terminal that is bolted to the frame someplace. I don't remember off hand exactly where it's at in the car. I seem to recall it coming through the firewall in the harness and terminated on the firewall, but don't hold me to that. It could be under the dash. I'll look at one of my test harnesses when I get home tonight and see if I can figure out more details. I have my car tucked away in a shed and can't get to it easily or I'd go find it and report back.

The ring terminal will have several wires all coming together to get grounded at the same place. W72 may be broke, or cut on it's way to this ring terminal, or the ring terminal isn't connected, or it is connected but there is corrosion preventing a ground.

I'm also going from memory that W72 does end up at a ring terminal and not through a connector or bullet type connector back to the battery. Regardless of the physical method, it has to reach a ground someplace. The harness does some internal splices that have been known to corrode. You can't see them unless you unwrap near the splice.

Len

[moozieman]

On 10/30/2019 at 3:47 PM, superlen said:

Physically follow wire 72 from the FIR to where it is supposed to connect to ground. It should run to a ring terminal that is bolted to the frame someplace. I don't remember off hand exactly where it's at in the car. I seem to recall it coming through the firewall in the harness and terminated on the firewall, but don't hold me to that. It could be under the dash. I'll look at one of my test harnesses when I get home tonight and see if I can figure out more details. I have my car tucked away in a shed and can't get to it easily or I'd go find it and report back.

The ring terminal will have several wires all coming together to get grounded at the same place. W72 may be broke, or cut on it's way to this ring terminal, or the ring terminal isn't connected, or it is connected but there is corrosion preventing a ground.

I'm also going from memory that W72 does end up at a ring terminal and not through a connector or bullet type connector back to the battery. Regardless of the physical method, it has to reach a ground someplace. The harness does some internal splices that have been known to corrode. You can't see them unless you unwrap near the splice.

Len

I believe that I have successfully grounded that wire. However when I go through your steps, I dont see all the wires that you are talking about. For whatever reason, I'm seeing what appears to be W11 on that relay connector. Is that correct?