Non-Splice Fuel Pump (It's a Bosch)

[OldSchoolNoe]

0 PSI at Schrader Valve, fuel pump connector is receiving signal to prime (for 2 secs), new relay = time for a new pump.

Most of the new fuel pumps will have you splice a flat connector...but why go through that when you already have a beautiful boxy connector. I am against chopping up my connectors, and lucky for me, Bosch still sells a fuel pump that still uses this original connector.BOSCH 67072 costs as much as the "good ones" ($197) and has great reviews. Haven't seen a post about it on this site, so here's one for the archives.

I will go ahead and install this fuel pump, will update when it goes out (Hopefully 4 years from now). I found it funny that I already ordered this part, assuming the van still has the "box" connector. I recently bought this '97 and it would be hilarious if the previous owner already spliced in the "flat" connector...but it ends well, as there is a connector sold on ebay that converts the "flat" connector back to the "boxy" connector for $22.

[MI_Ghost]

Information on the wiring adapter please?

[Mmusicman]

It's has always TOTALLY BAFFLED me that so many don't sell the pump with the correct connector on it. People wind up crimping/splicing on a harness, that can lead to failure later. Poor

[OldSchoolNoe]

Information on the wiring adapter please?

https://www.ebay.com/itm/Fuel-Pump-Wiri ... Sw-itgCyZ2

I searched for "fuel pump wiring harness 97 safari" supposedly it also fits '01 Astro

This adapter is used if you buy a fuel pump that takes a "boxy" connector [2x2] and you have already spliced in a "flat" connector [1x4] to your harness. It doesn't work the other way around.....come to think of it....why don't they just make a "converter adapter" instead of having to splice in the first place!? My guess is that the OG 2x2 connector had "melting issues," so there is no purpose in keeping that connector.So then why did I buy a fuel pump that uses that melt-prone connector? Well, I wasn't aware of that issue and I might be in for a surprise down the road

[AstroWill]

If the connector is a known problem, makes sense to replace it.

[Leeann_93]

The original configuration was a problem. It tended to cause arcing/burning. So GM redesigned it.

There's a reason to use the new-style connector vs. the old one. A good reason.

[OldSchoolNoe]

Dropping the tank to change fuel pump and the fuel pump connector doesn't look right. It has a white wire that goes into the body, and a black wire that is chopped. This could be a fusible link. That bolt nearby looks like a "ground" bolt. I hope this black wire is not a ground that the previous owner accidentally chopped up.

It is a fusible link right?

[OldSchoolNoe]

New Fuel Pump, New Fuel Pump Relay, and new Cap and Rotor. '97 Safari. Need advice on what to check. Currently 0 PSI do not hear a prime.

Previous pump 0 PSI, decided to change. The fuel needle jumps like crazy now.

[WildBorego]

check your relay and your fuse

[CopperFiremist]

Check power and ground at the connector before it goes to the pump in front of tank, IIRC it grounds on that cross section area.

[OldSchoolNoe]

check your relay and your fuse

Relay is "out the box" new and the ECM-B Fuse (20A) is not blown. The fuse runs hot at all times so checked voltage with multimeter. It read 0.06 Volts, huh 0.06? What did the battery read? 0.06 volts. That's insane, yesterday reconnected the battery after conditioning it to 13.04 V, now this morning it's down to 0.06V? Not only am I getting 0 PSI at fuel pump, something is really sucking that battery dry. Oof what's the next move? Re-charge that new battery and perform a parasitic draw test.
What could be sucking up that much juice?

[Mmusicman]

A dead battery is usually a good reason for no fuel pressure...

[Rod's Trucks]

It should be obvious, you need to solve the battery discharge issue first.
With a good battery, it takes a significant draw to drag a battery that low, and quite frankly, I do not think I have ever measured a battery at .o6 volts. Even an old junkyard battery will usually measure a few volts, so I an suspicious of your measurement. A battery that low may never be able to accept recharging ( I have never had an opportunity to try one that badly discharged, but even one a three or four volts is most likely junk)
Put your voltmeter in-line with the positive battery cable ( disconnect it from the battery ) after recharging the battery. If you have a significant current draw, it will read battery voltage.
Start pulling fuses, one at a time, and checking for a major change in the measured reading. You can do them all, or one a time, but if you are not sure about getting them back in the correct slots, replace each fuse as you check it, and then try another one.
One of the fuses should make a significant change in the voltage reading. There are some circuits that normally draw a small amount of current ( namely the radio for memory), so do not assume you found the culprit if you pull that fuse and the reading drops some. Remember an open door will try to turn on a courtesy lamp, so have the doors closed.
Hopefully you will find the problem circuit, but if not, you may have to resort to pulling all the fuses, and trying it again, by putting them back one by one. A wiring diagram would be very helpful once you have isolated the fuse that is for the problem circuit.
If you find the problem circuit, come back with more information and get more help.

Rod Johnson
Issaquah, WA

[MechBob]

Do not know about the "bolt/screw" Do not have factory diagram, for your unit.But,by other GM wiring "standards", inside that shrink wrap could be a diode,or even a resistor,or capacitor,to protect the pump and sending unit from voltage surges.

[OldSchoolNoe]

Found the problem fuse it is labeled "Lighting (40A)"

Set multimeter to 5A and initial reading (red probe on ground post/ black probe on disc. ground terminal), read -9.12. Removing the problem fuse = -0.08. Just to verify I re-inserted it and meter jumped to -9.65.

I noticed that the open rear hatch button does not work. No visible lights are on, all doors are closed.

I do not have access to a 97 safari wiring diagram.

[Leeann_93]

Yes, the ground is a bolt into the crossmember there.

This is before I wire-brushed and reinstalled it - after I replaced my pump.

[AstroWill]

That kind of amperage draw says headlights.

Get yourself the GM Techline eSI, will get you 90% of the way there as far as diagrams go, a lot should be the same as 98.

[AstroWill]

Grab the GM Techline eSI from the links in my signature and get yourself the wiring diagram. Heavy black screams ground wire to me. Depending on how they did your year you will have the 2 fuel level sender wires, 2or3 vacuum sensor wires, and 2 wires for the fuel pump.

Needless to say, going blind without a wiring diagram isn't really the best way to go about it.

[OldSchoolNoe]

Found and fixed the parasitic drain, I had a huge chuckle about it. Still 0 Psi at fuel pump will upload a diagram on what I have tested so far.

As for the parasitic drain, I could not find a specific diagram for the 40A Lighting fuse. Good thing this van still has the owner's manual. It says that fuse controls the Park Lamps Fuse, DRL Fuse, Headlamp and Panel Dimmer Switch. I took out those 2 fuses from under the driver's side fuse box and still draining. Last to check is the "Panel Switch" and Voila! Some clown had left the headlamps on, but the funny thing is none of the bulbs work. Turned switch off, draw = -0.46. Reconnected battery and tested lights, confirmed none of the bulbs turn on....that's for another day. Back to the fuel pump

[OldSchoolNoe]

Took out the fuel pump relay and took a multimeter to the 5 pins. That "pin 87" orange wire reads battery voltage. I can conclude that HOT runs from ECM B Fuse up to this point.

I did get a 2 second "signal" from "pin 85"

The dead circuits are that red wire and grey wire.

What's the next step?