Plugs are under your valve cover. You'll want to x everything else off your list before bothering with your glow plugs.

Seriously, have someone cross the large terminals on your glow plug relay with a screwdriver while you try to start the truck.

If it starts instantly like magic, you have a bad relay.

 

Got pull the valve covers

 

I believe it's going to be on the left side of the engine. Am I correct in assuming I'll have to get to it by removing the engine cover inside the truck? In anticipation of this being the porblem I called my bud @ Car Quest. He said the relay is special order and costs $180. Ouch

 

No, its a little brown electrical relay behind your fuel filter. You shouldn't have to remove anything to get to it.

Depending on the year of your truck you may also have an air intake heater, it looks the same and is next to it but in a different spot.

NAPA part number GPR110 or GPR109...shouldn't be more than $70. do you have a NAPA near you anywhere?

Here's a pic of the 2 relays (the right side of the pic is the front of the truck for orientation)



Of the two brown relays, the on one the left is the GPR. The other is the AIH relay.

 

ok got to the relay...a bit more difficult in a van as it's "under the dash" but removal of the laternator should make the job easy. I jumped it out and the truck started. I tried again without jumping it out and the truck started again. I'm going to replace it anyway. Thanks for all the help and good advise.

ps..the tow truck called a few mins ago and said he'll be here tomorrow. I told him....don;t bother

Rex

 

Well what the relay does is supply power to your glow plugs, which in turn pre-heats your fuel before you turn the truck over. In contrast to a gas engine, which relys on spark plugs to ignite the fuel, a diesel uses its own compression to ignite its fuel. The colder the fuel, the harder it is to ignite..is I guess a easy way of explaining things.

Since you got it started, and it ran for a minute or two, your fuel warmed up just enough that it made it easy to start when you turned it over once again.

Yay. on the tow truck driver.

Edit: And Rex, when you get your new relay, use an end wrench to put the new one on. They are just plastic and can break pretty easily if torqued on with a socket.

 

Place a voltmeter across the large terminals of the Glow Plug relay, the reading should be 12+ volts before relay is energized. Once the relay is energized the voltage should drop to less than 1 volt. A reading of more than 1 volt when energized means the contacts inside are badly pitted and cause a voltage drop due to poor connection.

 

will do lisa. I hpe to find one tomorrow....and nick...I will check that before replacing as I suspect it's possible I also have several bad glow plugs. Thanks for the heads up.

Thanks