I own a 7.3 idi and my glow plug relay keeps on clicking and after replacing/warrantying about 3 relays each one has clicked right after installation.

-All of my glow plugs are good

-I am getting 10 volts through the glow plug connectors and on glow plug side of relay.

-Ground wire that grounds to the block is getting continuity to the battery's

-All positive posts are getting battery voltage.

Am I missing something? Truck still doesn't seem to start as it should when it's around 40-50 degrees... From what I understand the relay should only click once instead of multiple times. The wait to start light turns on and off as it normally should. Thanks

 

Clicking in less than 20 seconds or so means you have one or more glow plugs or wires creating n open circuit. The controller is supposed to click only once plugs are up to temp

 

Here's mine starting at 10f. You can see how long relay stays on before voltage starts clicking. The colder the longer it stays on. Clicking is normal after 10 to 20 seconds depending on temp. If it sooner than that you have a have a bad glow plug or two

 

Thank you guys for the replies. I could have been a little more descriptive. The problem only comes on after the wait to start light turns off. After the light turns off the relay will click a bunch of times and the voltage meter spikes up and down when it clicks. After the truck is started it'll do it again. I also forgot to mention that I am getting 9k ohms through every connector and on the glow plug side of the relay.

 

That's actually supposed to happen. Pre-start is the 'keep warm' circuit basically; post-start is "afterglow", to help with emissions/keeping it running for the first few seconds.

Note: If the glow plugs are working and warming up correctly, hard starting can be because of fuel draining back overnight, OR slow cranking speed.
A worn/older IP has to crank quickly enough that internal pressure builds up enough to actually inject into the cylinder.
If you are getting white smoke while cranking, this is NOT the issue.
HOWEVER, white smoke indicates that you aren't getting enough heat to fire -- Either from slow cranking(letting the heat of compression bleed off before it gets hot enough), or from glow plugs not working correctly.

 

Ok, I get white smoke everytime I start it when the truck hasn't been running after 4 or 5 hours, after the truck has been started and I go back to start it again even 30 mins after its been shut off, there's no smoke and it starts right away which lead me to glow plugs. I don't think battery's are an issue cause I got both 850 CCA and they're brand new.

 

Yes, I was a victim of Bad AUTOLITE Glow Plugs!
My controller and glow plugs were NEW and just clicked when starting, NO INITIAL WARMING OF GLOW PLUGS!
So I checked and replaced my glow plug harness with ones I made. Still no warming, just clicking. Shorting across the relay
terminals would result in warm glow plugs and let the engine start so the glow plugs worked.
But the controller did not sense resistance from the new Autolite glow plus.
I bought and installed Motorcraft ZD-9 glow plugs and my controller worked perfect, wait to start lamp on for 20 or 30 seconds,
then start the engine. PERFECT.
AUTOLITE GLOW PLUGS ARE JUNK. DON'T BUY THEM EVER!!!