GPR "Only " thread

Reply Subscribe

Thread Tools

Search this Thread

Jan 8, 2012 | 08:02 PM

#16

F350-6

Post Fiend

Joined: Mar 2007

Posts: 26,966

Likes: 50

From: Texas

Quote:

Originally Posted by richdawg

https://www.ford-trucks.com/forums/1...with-pics.html
I did this GPR mod using a momentary switch. It seemed as though I got a lot of negative comments so I'm sure not recommending any one do this mod, but it does work well for me so far.

The comments don't really seem too negative. They key is using a momentary switch and not a toggle switch. It seems that some may not know the difference.

The reason I suggested the starter relay is that from what I've seen and read, many of the GPR's use only a copper plating on the contact disc which makes them burn through and corrode quicker. Since we don't read about nearly as many failures of the starter relay as we do the GPR, then I was assuming (and we know where that gets you) that the starter relay might be more robust or use a full copper contact inside it.

The momentary switch won't be of much use if the GPR is a piece of junk, and I don't think you can activate the starter relay by a ground signal like you do the GPR.

Jan 8, 2012 | 08:46 PM

#17

DRRXR

Post Fiend

Joined: Feb 2009

Posts: 8,773

Likes: 1

From: Texas Coast

Some intersting articals
http://www.ebay.com/itm/Ford-diesel-...item3efa2e2aab

THEN THIS ONE
When you open it be sure to scroll
FORD DIESEL GLOW PLUG Relay 6.9 and 7.3 Powerstroke | eBay

EDIT
I had to fix the top link

Last edited by DRRXR; Jan 8, 2012 at 08:51 PM. Reason: fixed the link

Jan 9, 2012 | 08:32 AM

#18

tjc transport

i ain't rite

Joined: Mar 2005

Posts: 65,554

Likes: 5,590

From: Marlboro Mental Hospital.

in 2 years i went through 4 napa GPR on my 02.
then i put a stancor in 3 years ago. it is still working fine.

Jan 9, 2012 | 08:41 AM

#19

DZL JIM

PREMIUM SPONSOR

Joined: Sep 2003

Posts: 2,630

Likes: 217

From: North East Ohio

Quote:

Originally Posted by F350-6

...The reason I suggested the starter relay is that from what I've seen and read, many of the GPR's use only a copper plating on the contact disc which makes them burn through and corrode quicker. Since we don't read about nearly as many failures of the starter relay as we do the GPR, then I was assuming (and we know where that gets you) that the starter relay might be more robust or use a full copper contact inside it.....

I'm not liking the comparison between a starter relay and GPR based soley on use.
The starter relay is active for only a few seconds, the GPR for 2 minutes each time the motor starts (well, not always 2 minutes but when it's on it's on for a long time.) I'd have to think the loger duration of current has a lot to do with the wear on the internals. It's not just a quick zap like a starter relay.

Like, flick your finger throw a candle flame and you can do that all day long.
But hold your finger in a candle flame for 2 minutes and you won't want to do that again.

I might be slightly off, but I know higher amp/current will heat things up over a longer active time.

Thoughts?

And I now use relays from Alliant Power (OEM) and so far several of mine have lasted 3 plus years.
On my Black Truck (not daily driver) that relay has got to be 8 years or older, GPR 109.

I wonder if the draw from certain glow plugs has an adverse affect on the GPR, too. I know some heat fast and draw less current than others.

__________________
'96 7.3 F-350 Reg Cab 4x4 - bought new.
'04 6.0 E-350 custom 4x4
'08 6.4 F-550 Reg Cab 6 spd 4x4
'17 6.7 F-250 KR ccsb 4x4

Jan 9, 2012 | 08:51 AM

#20

Ken_C

Elder User

Joined: Aug 2009

Posts: 869

Likes: 1

From: Michigan

Quote:

Originally Posted by tjc transport

in 2 years i went through 4 napa GPR on my 02.
then i put a stancor in 3 years ago. it is still working fine.

Same Here. the key is having good glow plugs and wiring. if you have a shorted glow plug thats going to ruin the uvch and maybe the gasket. also the glow plug circuit has a fusible link that protects against a dead short. my stancor GPR has been in for 2 years. thats 2 michigan winters. its gettin used trust me. I do check the voltage drop through the gpr once in a while just to see if its working good. its been prety frosty here and I have not plugged in the block heater yet.

Jan 9, 2012 | 09:16 AM

#21

Talyn

Hotshot

Joined: Oct 2003

Posts: 17,799

Likes: 103

From: Ashland City, TN

The best way to save them is to put in a toggle switch to put them on and off.

I'll have to check out that link for the one madvan was talking about.

Jan 9, 2012 | 11:13 AM

#22

madpogue

Lead Driver

Joined: Oct 2003

Posts: 8,476

Likes: 37

From: Madison, WI

Quote:

Originally Posted by joe_13894

Just curious if some of you that burn them up all the time have the glow plug relay cycling or just staying on? I would think that the cycling has got to do much more wear on the contacts compared to just staying on steady.

I've noticed that if both batteries are good, battery connections are good and all glow plugs are functional that the glow plug relay won't cycle.

Correct. The GP circuit should NEVER "cycle" on and off. That is, by definition, an indicator of a problem. Probably one or more glow plugs is drawing so much that it's dropping the voltage, causing the relay to open for insufficient voltage, then when the battery voltage recovers, the relay closes again, and the cycle repeats. It's a handy indicator, but def. an indicator of a problem.

Quote:

Originally Posted by DZL JIM

This^^^. The starter relay isn't rated for the longer contact-closed time that the GPR requires. Also, the starter relay grounds through the mount, so an isolated mount and some wiring adaptation would have to be fabbed. The starter relay is a _lighter_ duty application (remember, it's only relaying the solenoid circuit, not the main starter circuit) than the GPR.

Jan 9, 2012 | 11:35 AM

#23

Hussler

Postmaster

Joined: Sep 2007

Posts: 4,195

Likes: 6

From: Medford Oregon

The glow plug relay will only cycle on and off repeatedly when there is a system voltage condition greater than 14.5 volts.

I see this happening when I start my truck cold and take off immediately as my alternator output is 14.6 volts when rpm's get up. Therefor I seldom do this anymore and simply wait for the GPR to cycle OFF.

FTE Stories

Ford Trucks for Ford Truck Enthusiasts

Top 10 Fords at 2026 Carlisle Ford Nationals

Joe Kucinski

3 Best / 3 Worst Parts of Modern Ford Ownership

Brett Foote

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

Pouria Savadkouei

Every 2026 Ford Engine Explained

Brett Foote

10 Ugly Ford Trucks That We Still Kinda Love

Joe Kucinski

10 Things Every Truck Owner NEEDS (2026 Edition)

Michael S. Palmer

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Verdad Gallardo

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Joe Kucinski

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Brett Foote

Top 10 Ford Truck Tragedies

Joe Kucinski

Jan 9, 2012 | 12:44 PM

#24

joe_13894

Fleet Mechanic

Joined: Aug 2007

Posts: 1,508

Likes: 2

From: The boonies by Dallas OR

Quote:

Originally Posted by Hussler

The glow plug relay will only cycle on and off repeatedly when there is a system voltage condition greater than 14.5 volts.

I've noticed that I don't have to wait for the complete cycle, just wait a bit. At idle I see about 12V with the glow plugs on. That will still draw down the battery. If I wait about 30 seconds after starting, it won't cycle when I take off.

Jan 9, 2012 | 06:43 PM

#25

F350-6

Post Fiend

Joined: Mar 2007

Posts: 26,966

Likes: 50

From: Texas

Quote:

Originally Posted by DZL JIM

Good points. I need to find one I can cut open to compare the guts. If the GPR is using a cheap copper plated disc and the starter relay uses a solid copper disc, maybe it would work better. Otherwise, you're probably right.

And again, I don't know how some of you put up with the cold, I mean what it's like in the colder weather, but I don't think you really need the full two minutes of glow plugs. Say 20 seconds or so? Maybe less depending on temps. I like the idea of a momentary switch or push button better than a toggle. As soon as you remove your finger, the power goes away. I'm not sure 20 seconds at a time would burn up a starter relay. Of course I haven't checked the price on them either. Maybe it would be a foolish move based on price alone.

Jan 9, 2012 | 08:00 PM

#26

JCart

Tuned

Joined: Jan 2008

Posts: 294

Likes: 16

From: Kamloops, BC. Canada

My Stancor has been working well since install guessing over a year and a 1/2 now. Would usually have to replace the stocker every year, living in a cooler climate.... guess we shall see, but so far flawless. iirc they where same or just cheaper than stocker here in Canada.... $90.00 at the time for stocker.... and shipped, Xborder duties was about the same...

jrc

Jan 9, 2012 | 08:31 PM

#27

Action4478

Thread Starter

Hotshot

Joined: Aug 2006

Posts: 10,764

Likes: 39

That is my feeling . A more substantial relay , all my GP's are working . PCM is working ,Batteries are load tested & up to it ,, The weak point seems to be the relay ..