7.3 starting problem

[Verbaan]

Hi I have a 2000 f250 and I am having starting issues. If the truck is plugged in when it's cold it starts every time. If It is not plugged in for at least a few hours it will not start and the relay under my dash clicks as I'm turning it over. I have no idea what it is. I replaced the relay twice already as we'll so confident it's not the relay. Help.

[Mike O]

Check the glow plug relay (located behind the fuel filter) this check can be accomplished with a test lamp. 1) Place the light on brown and yellow lead
2) turn the key to start position. while the glow plug indicator is lit on the dash so should the test lamp. I have replaced two of the already on my 2002 7.3, the batt post terminal burns out. If you have a California make then you have a control module. I can not offer any help with this. You tube has videos that can give you a better idea of what to look for.

This a link for an upgraded Relay
586 105111 White-Rodgers | Mouser
or you can just go with the stock version

Hope this helps

[jays big blue]

Mike-o is right, good chance its the gpr. Mine did the same thing...gets progressively worse, especially in the winter. I went with the cheapy from napa gpr110...like 25$. I'll order a stancor someday.

[akmikek]

I am having similar problems and tested my GPR with a meter. When i turn the ignition on i the get a raising voltage that stops at 10.89 volts. Is that enough power for the glow plugs?

[Mike O]

If your taking the measurement from the load /glow plug side, that is not enough. Wear and tear is causing resistance, the resistance causes heat which will eventually burn out one of the posts. This is assuming the battery side of the relay is reading 12 volts or higher.

[Ressurektion]

I replaced my relay and it solved my problem temporarily. The bad relay caused me to look into my problem further... 6 out of the 8 plugs were bad.

So in retrospect... there was a good chance my bad plugs caused my realy to overheat. Maybe.

Borg-Warner #GPR11
Motorcraft #DY861

California emissions trucks use
BWD #R6036
MOT #DY876

[Verbaan]

I tested the gpr and its reading 11.5 on both posts. I am wondering if when it is cold it takes more power to crank it over. Possible my starter Is using more power when it's not plugged in? And both batteries are only 6 months old.

[Verbaan]

Also when my truck is not plugged in I find my relay under my dash clicks and then I have to unplug my batteries to reset the relay. I have replaced the relay like 8 times I know it's not the relay.

[Verbaan]

Do you know anything about the smaller posts on gpr and how to check them?

[akmikek]

The smaller posts are for the ignition i believe. When you turn the ignition on to wait to start position, it opens the swith on the relay and lets power through. It should be closed without the key in the ignition and open (45 secs?) when key is in wait to start position. I installed a new GPR today and i had 12.0 volts on hot side and 11.11 on other side. i do not know what is wrong. I will have to test my glow plugs but i am having a hard time getting the harness disconnected.