Fuel pump Isolator

**IZwack** · 09-21-2010, 07:11 PM

Why is the in-tank fuel pump electrically "isolated" (plastic thing that it slides into) ?
I'd think that you'd want the pump's body to be grounded with the rest of the vehicle, but apparently not.

**Turdle** · 09-21-2010, 07:22 PM

I always thought it was to prevent a spark in case a (bare) wire did come into contact with the housing

*ranger7ltr* · 09-21-2010, 09:09 PM

This is a picture of my 99 Explorers' fuel pump... There is a rubber insulator at the bottom of the pump to deal with vibration and there is a ground on the fuel level sender that also goes to the negative side of the pump...

Here is the pump...

**IZwack** · 09-21-2010, 09:30 PM

I dont think it matters what year or model as all of the in-tank fuel pumps I've seen are isolated.

I'm talking about the plastic sleeve that slides over the pump itself - which isolates it from the metal assembly.
Example, from a Crown Victoria:

*ranger7ltr* · 09-22-2010, 12:03 AM

That pump is isolated from grounding on the fuel sender support... The ground is for the level sender not the pump like I thought... I am looking at a new pump on my desk...

I always thought the rubber surround was just for noise/vibration/harseness...

09-21-2010, 07:11 PM	#1
IZwack Germantown, MD Join Date: Feb 2003 Posts: 22,381 Vehicle Specs (Original Poster)	Fuel pump Isolator Why is the in-tank fuel pump electrically "isolated" (plastic thing that it slides into) ? I'd think that you'd want the pump's body to be grounded with the rest of the vehicle, but apparently not. __________________ »»»»»...how'd the moon get there, how'd the moon get there?

09-21-2010, 07:22 PM	#2
Turdle Old and in the way Humboldt, Kansas 2000 Mounty Join Date: Jun 2003 Posts: 23,785 Vehicle Specs	I always thought it was to prevent a spark in case a (bare) wire did come into contact with the housing __________________ Jon 2000 Mountaineer Turdle-gone Vitamin D Wagon Sold also

09-21-2010, 09:09 PM	#3
ranger7ltr Elite Explorer Great State of Texas 1999 Sport Join Date: Nov 2001 Posts: 1,136 Vehicle Specs	What year model fuel pump are you talking about? This is a picture of my 99 Explorers' fuel pump... There is a rubber insulator at the bottom of the pump to deal with vibration and there is a ground on the fuel level sender that also goes to the negative side of the pump... Here is the pump... Attached Images __________________ When in doubt, use a bigger hammer! 2008 Dodge Charger R/T 2003 Ford F-150 XLT Supercab 1999 Ford Explorer Sport [new playtoy] 1983 Ford Ranger V8 [soon to be gone]

09-21-2010, 09:30 PM	#4
IZwack Germantown, MD Join Date: Feb 2003 Posts: 22,381 Vehicle Specs (Original Poster)	I dont think it matters what year or model as all of the in-tank fuel pumps I've seen are isolated. I'm talking about the plastic sleeve that slides over the pump itself - which isolates it from the metal assembly. Example, from a Crown Victoria: __________________ »»»»»...how'd the moon get there, how'd the moon get there?

09-22-2010, 12:03 AM	#5
ranger7ltr Elite Explorer Great State of Texas 1999 Sport Join Date: Nov 2001 Posts: 1,136 Vehicle Specs	That pump is isolated from grounding on the fuel sender support... The ground is for the level sender not the pump like I thought... I am looking at a new pump on my desk... I always thought the rubber surround was just for noise/vibration/harseness... __________________ When in doubt, use a bigger hammer! 2008 Dodge Charger R/T 2003 Ford F-150 XLT Supercab 1999 Ford Explorer Sport [new playtoy] 1983 Ford Ranger V8 [soon to be gone]