I will check this tonight. Is this with key on and relay out right? Meter lead black end on rad support ground (or any good ground) and red doing the probing set to DC volts? Check 85 for voltage like the rest of them? Ground check on 85 I use continuity and go from 85 to body ground to confirm good ground?

I thought 86 only gives power if car is cranking/running so the relay would have to be in? Do you take the cover off the relay?

Before I do any of this, I will mention I put the new fuel pump in today and so far so good (for now). Line pressure good and holds after shutting car off. I'm really starting to wonder about whether or not the stuff RA sends is new or someone else's return. I've read stories. This new pump is from Summit and it came straight from Delphi.

The new pump- back probed harness behind rear passenger seat while car was running on grey wire and it was just a little over 12 volts. I don't remember the exact number but can check it again. Took a little research to learn that you'll only see voltage on that wire when the car is running/cranking that is why I question #86 on relay about having 12+ volts.

So, why do I not see the car's running voltage which would be higher than the 12 volts i'm seeing on the grey wire?

Lastly, do I even need to to additional voltage check on pump relay if I'm seeing this voltage on the grey wire?

I appreciate you Donbrew, you are very knowledgeable!

 

Delphi pumps aren’t necessarily known to be good, AC Delco pumps are, now you probably won’t have any issues. Will RA accept the defective pump as a return?

 

Yes, RA is taking it back and refunding me. The guy I talked to by email was mad at me because I didn't buy another pump through RA. They specifically told me they would not send me another Delphi because they had already sent me two. Delphi is at the top of the pumps they have. I asked him if I was supposed to downgrade in order to stay with RA and he didn't reply. All he did was put Summit down.

I thought Delphi and AC Delco were essentially the same pump. That's what summit told me. The Delphi actually cost more. Summit had exceptional customer service but they don't stock any of the fuel pumps and have to have everything shipped direct from factory. So the wait time is much longer.

But yeah, if this one goes I'm done with Delphi! I was originally going to get the AC Delco but summit told me it was the same as Delphi and they could get the Delphi to me faster

 

ACDelco is owned by GM. The old AC Delco...
well here's the wiki
http://ACDelco - Wikipedia https://s...Q1hqq7Iz6qfvTT

 

the old AC Delco was good! Now, who knows anymore. I'm sure if you buy it from the car dealer you're getting the real thing but I don't have $600-$700 for a fuel pump.

I'm sitting here looking back over the diagram Donbrew posted about four posts earlier. When I drained the gas from my tank I jumped the relay circuit. The pins i jumped were diagonal from each other and by his diagram it would have been numbers 30 and 86. How did this supply power to the fuel pump if number 86 is trigger from the computer. By the diagram the only way jumping would work would be 30 and 87.

 

everything checks out for voltage on relay circuit. It has occurred to me that the diagram Donbrew posted was just for schematic purposes and the basic flow. The pins on my relays are not in this order. This is why my diagonal jump worked because I was actually jumping #30 and #87.

Voltages on my circuit are: #30-12.58 volts, #85- 0 volts, #86- 11.8 volts with key on but jumped to 13.5 while cranking, and #87- 0 volts

It appears everything looks good in the circuit and from what I can tell there is nothing that would be causing fuel pumps to go bad. I don't know, I'm not a pro just a DIYer

Only thing I really should do yet is a voltage drop test. Should have done that while I had the tank down but I just wanted to get done. I have to drop the tank again sometime soon anyways to fix some rust up under where the corners of gas tank are. Saw it when i dropped the tank for fuel pump. I'll do the test then.

 

Delphi was GM, and is still a GM supplier.

In 1994, Delphi was created (by combining a bunch of GM components operations) and owned by GM until 1999 when it was spun off as a publically traded company.

Lotsa stuff happened, like bankruptcy (ca. 2005,) and the whoring around of various products, operations, and brands. And skewering the employees out of pensions, Delphi made those ignition switches that got recalled. Then Borg Warner owned it.

It's complicated.

Now Delphi is (not just) a brand owned by Adaptiv.

I only mention all that because Delphi coulda made the original fuel pumps, and, who knows, might still make them for ACDelco, which at this point, is just a brand and the name of a GM parts division. ( I'm not saying they don't make anything, just that the name on the box alone does not mean they made it..)

To keep the confusion complete, AC Delco Systems (not to be confused with the aforementioned ACDelco brand) was actually absorbed by Delphi in 1995.

Feel free to try to make sense of it all:

https://en.m.wikipedia.org/wiki/Aptiv

https://en.m.wikipedia.org/wiki/ACDelco

 

Then it’s up to the future reader to decide.
All I know is I have installed both brands and didn’t have any problems, however some members have reported the Delphi product to be a little bit different and fail .

 

Well, once again I'm hearing fluctuations in the speed of this new fuel pump when at idle, particularly when applying brakes. Going back to the underlying issue of my first few posts on this thread which seemed to be voltage problem. I replaced the battery and we confirmed proper voltage from alternator was charging battery. We also suspected a parasitic draw which was draining battery and I performed test as per Donbrew's video he posted a good many posts earlier and the test was showing 1.7 amps draw but then after 30 mins the meter read zero so I just thought the car hadn't fully gone to sleep.

I performed all these test again today. Started with battery voltage at the battery first thing before even starting the car and got 12.4v which already telling me there's an issue. It's a new battery. Next I started car and read alternator voltage which read 14.6v so it appears to be charging the battery. This time I checked ripple voltage which I hadn't done before and it read 28v. Can this be right? Had the meter on A/C volts. The meter I have only goes as low as 200 so maybe this is just a decimal issue. But 28 volts???????

Also checked for parasitic draw again per Donbrew's video. Still have the 1.7amp draw. This time I waited an hour. All doors closed, rear gate hatch striker tripped, keys out. Narrowed it down to BCM. I pull the radio fuse and interior light fuses and it will drop to .8 amp. When I pull the BCM2 fuse under the hood the meter reads zero completely. What is a normal amp draw for this car? Note- I've completely unhooked the aftermarket radio with fuses in and it made no impact on the draw.

 

Fluctuating speed of the fuel pump? , are you noticing the headlights brighter under acceleration then they dim when it’s off throttle? Worn serpentine belt and tensioner? Loose alternator mounting bolts? Loose or dirty ground wire connections? Loose or dirty positive connections to the fuse block under the hood , the starter, at the alternator? It has to be something simple and easily overlooked. These trucklets are usually not that complicated to repair.