The fact that this involves 2 separate ground points is important and it was obscured by the schematics being truncated right in that area and by both circuits being named as "CKT 150".

However, it still seems car has an open ground at the fuel pump motor (Point D), as per my previous Post analysis. Now it can be pinpointed to Ground Point G401.

Let's revisit one earlier post with the new information on hand:


You are obviously referring to ground CKT 150 at Point D, not at the coil of Relay 35, and you are getting a floating voltage instead of a solid 0v. In addition to that you brought +12v directly from the battery, but the pump didn't work until you provided a direct ground as well. As I mentioned before, it seems Ground Point G401 needs a little TLC

It also seems you may have a separate problem involving Relay 35, as pointed out by the lack of voltage in CKT 120 (Pin 87 - Relay 35 and Point A from pump motor). This needs to be troubleshot as well, but it will be easier if you make sure Ground Point G401 is fine first (Point 3 in diagram below).

 

Good morning guys, sorry I have not been in touch for a few days.. I had some other issues come up, and had to take a few days away from the car.. and the computer.. but before that, I did find a NEW issue..I have now discovered a gas leak at the fuel pump..not too keen on messing with electricity until I resolve the gas leak.... leak is coming from main gas line going into evap . i am thinking I need to drop the tank to get to the evap line. Problem with that is that many years ago I had some muffler work done and did not realize they WELDED the exhaust bolts. So now I have to cut that with a grinder. so I face electrical + Gas or Sparks + gas.. I just cant seem to win with this car.

FYI... To go backward a bit.. all of this started when the car stayed parked for a while and squirrels decided to build a nest under the hood.. many chewed wires..I found a break at EVAP.. I THOUGHT that was the issue, was trying to figure out how I was going to drop the tank then, but everyone said "evap will not prevent the car from running" so I moved on to replacing the fuel pump.. (it was the whole assembly, Not just pump).. but now I am assuming that the leak is coming from the evap line (another chewed spot that I did not see) and maybe as a safety feature it is sensing the leak and that is the reason it wont run.. so now back to the issue with dropping the tank again. May try to use a hand pump to drain tank as much as possible.

 

@rudystrick Sorry to hear that. Did you check and clean Ground Point G401 as per Post 21 above? Just trying to make sure you didn't miss those pointers. Checking that ground will only take a few minutes and it will give you something solid to continue from

 

Checking Ground G-401 (with the key off) will NOT introduce any sparks or electrical issues. G-401 is in the passengers rear wheel well on the side of the frame (just aft of the tire) Its a stud with a 10mm nut and its exposed to the elements. It gets lots of abuse.

Simple to check and clean. Soak in penetrating oil and remove the nut. Clean the stud, frame area below the stud the eyelet for the wire and the nut with wire brush. While the wire is off the stud, check continuity between the wire eyelet back to pin "D" on the pump. Should be zero OHMS..

BC

 

BC, you are saying G401 is "passenger" side???... I have not checked that,, but If I am looking at the diagram right G401 is #3 on the diagram is on the DRIVER side.. I did clean that one but have not tested it yet... just double checking which location, passenger or Driver side rear wheel.. am I missing something or was that a mis print?

 

G401 is on the DRIVERS side on the frame rail inboard of the back part of tire...remove the tire...all odd number grounds on left side and even on the right !!

 

[QUOTE=C5 Diag;1599379644]G401 is on the DRIVERS side on the frame rail inboard of the back part of tire...remove the tire...all odd number grounds on left side and even on the right !![/QUOTE


Thank you for the clarification, i have cleaned that ground .. but have not tested it yet.. I will look at that tomorrow. just one more silly question.. Is it possible that i put the fuel pump relay in "backwards".. or is it like the fuses. .does not matter which direction they are installed ? I cant find any info on that

 

The fuel pump relay will work either direction !!...here is a picture of the ground...the rear of the tire is to the left !!...pretty sure your 99 and my 01 are in the same location !..if you jumper CKT 1639 and 120 ( load side of the relay ) key ON and the pump works the wiring from the pump fuse to G401 is good !!...you have to be concerned with the control side of the relay !!...I did a video in thread #7...look at the bottom of the relay and see if they are numbered 87,30,86, and 85 !!..best way to check 401 is disconnect pump connector and with the OHMS setting you should read continuity from 401 to the black wire of the harness...I did this with 401 removed !!

 

It is indeed Point 3 on the driver's side, as shown on the diagram I gave you above, and as C5 Diag confirmed. I'm sure it was just Bill typing fast, and that has happened to all of us one time or another

Just to confirm you had eliminated 1 problem, you should have measured resistance between Point D (ground at the pump motor) and frame before cleaning G401 (probably open or reading high) and then again after cleaning it (ideally 0 ohms). Not a big deal and nothing to regret, since what matters are the results

What you can do is bring again +12v from the battery to Point A at the pump motor, as you did before, and the pump motor should work without having to provide an extra ground to Point D at the same time as well . You can also do what C5 Diag suggested in a previous post and remove the pump relay and jump pins 30 and 87 with key ON; it should work too.

 

DAG GONE IT That will teach me to try and type and do work at the same time. Yea,, its in the drivers side.

Sorry for the confusion.

PS...… The passengers side also has one of those ground studs BUT,, it only has a wire on it if you have a 97 or early to mid year 98. Its for the rear mounted EBTCM.

 

Thanks for the clarification and the additional advice...We will work on those additional tips this week.. Got a lot going on right now.. Now the F250 (Rudy's daily driver) is down as well,(big $$ problems there) have rental properties that need attention, (one is a complete re-model) MOTHERS DAY (for both of our moms) .. and other household jobs that need our attention.. this retirement thing is killing us. So long story short, please don't give up on us if it is a few days between posts, we are still working on the car but have to hit it between other jobs so it may be a few days between posts. Thanks again for all of the help you guys are giving us.

 

do you have another link to the video? I’m having the same issue, fuel pump isn’t kicking on when turned to on position but the car still cranks. Hot wired the fuel pump directly with a separate battery and it kicked on. So I know the pump isn’t the issue. Switch relays to no avail, and fuse isn’t blown. Cleaned both the rear ground and checked both grounds up in the front connected to the block. Still. Nothing. I’m at a lost

 

First what year is the car and what do you mean by "switch relays to no avail" ??...do you have a 12 volt test light and a DMM and know how to use them ??...also helps to have an old headlight bulb to use as a substitute load...you have either a bad wire or relay, a "control" issue or high resistance in the circuit.

 

i don’t have a test light no but i do have a multimeter. And sorry, I meant when I switched the fuel pump relay with a different relay, like the horn, it didn’t change anything. And cheers for the video I’ll watch that now

 

Best to use a 12 volt test light...get an incandescent not an LED one...below is the bulb I use as a substitute load.

 

I jumped the pump at the relay with a wire, connecting 30 and 87. Pump still dosent prime with key on. And then I tested each pin for voltage at the plug at the pump and got nothing on all of them. That’s with key on. So pump isn’t getting power at all.

 

FIRST you need to understand how a relay works...check the fuse with your test light...BOTH test points should illuminate the test light with key ON or START...the test light should illuminate at 30 when connected to ground and with test light connected to battery POSITIVE 87 should illuminate...the test light will find a ground through the fuel pump windings through ground...to check terminal 86 (control side feed) connect test light to GROUND and with key on or start the test light should illuminate...to check 85 connect test light to battery POSITIVE...if G105 is good test light will illuminate...if this testing is over your head seek out an auto electric shop if you don't have any electrical diagnostic experience...this is a very simple relay circuit...watch the video !!...YOU ARE NOT CHECKING FOR VOLTAGE AT EACH PIN !!