I'm pretty new to the PSD's but so far I love the thing. I recently changed out my glow plugs and glow plug relay since the truck has 100,000 miles and it was a little hard to start in the cold weather with the block heater plugged in.

Now that it only get down to 60-65 degrees at night, do I really need the glow plugs to start the truck? I had thought about wiring a switch to turn off the glow plugs in warmer weather to save the life of the plugs and wear on the batteries.

Any thoughts?

 

As I understand it needs to be 75-80 degrees before the GP's are not needed so in your case you still need them for awhile. Also if your truck is newer (I think '96-'97) the GP's have a temp switch that turns them off if not needed. I am not sure what year you have. There are some people that have the olde OBS's and live in the south that have put a switch on theirs for the reasons you listed. Hope this helps.

 

Yeah, mine's a 96. We haven't had that many warm nights, but even during the 85-90 degree days, the "wait to start" light comes on. Is there any way to find out if mine is equipped with the GP temp switch?

 

Not sure about the switch but watch youbattery gauge when the ignition is turned on in hot climate. It will drop down significantly if the GP's are energized. Check it out the next time you start it.

 

Yeah, I've been watching it and it still drops. I bought it last November, so I haven't had it during really hot weather, so I'll keep an eye on it.

 

check this link

https://www.ford-trucks.com/forums/6...pr-switch.html

 

Thank you, sir!

 

dont have to say thanks sir. my pleasure .

 

Question; Once the truck is warm do I have to wait for the Wait to start light to go out or can I just start without it. Or should a control switch be installed.
Thanks

 

Just out of habit I always wait but you can actually start it as soon as you put the keys in it as long as it is warm. If it is too cold it will let you know and not start or start rough.

 

I'm in that habit, too. I borrowed my dad's truck when I was fixing mine and I turned the key forward and waited a couple a second to start it. Probably not necessary on his Ford Ranger!

 

That's funny I have the oposite prob with the wife's EX. I hop in it and just fire it up. I guess it is because it is not my truck, different habits.

 

From my experience and the other mechanics that I know, if everything is right with a diesel engine (with a few exceptions) glow plugs are not need above 40 degrees. I have a switch on my glow plugs and I only turn my glow plugs on at 35 degrees or colder and I do not have any problems in starting my truck. I have tryed it with and without the glow plugs at degrees in the 40's and 50's and have found that there is not difference in the way it starts, 2 spins and it fires up. I have also put switches on 7-8 other PSD's and they also have told me that they do not have any problems starting in temps at or above 40 degrees.

The WTS (Wait To Start) light is not connected to the glow plug system. It is just a reminder. During cold weather the glow plugs will stay energized for up 2 minutes, (even after the engine is runing) but the WTS light goes off after a set time.

On the trucks that I have worked on, the 94.5 & 95's the glow plugs were energized "EVERY" time the truck was started. Others on here have advised that thiers did not come on everytime. On the 96-97's the programing in the PCM only energizes the glow plugs when the info from the Baro sensor, coolant temp sensor, and oil temp sensor are low enough. From talking to several Ford diesel mecanhics, they advised that the programming in the PCM has changed over the years to correct several problems that had been found with the system (the glow plugs being one). This probably explains the differences in the 94.5-95 trucks.

To know for sure if the glow plugs are being energized with every start, use a volt meter to read the power at the two larger terminals on the GPR (Glow Plug Relay). With the truck off, one terminal will have constant power and the other terminal will have no power (power is "NOT" flowing through the GPR). Now test the terminal that did not have any power right after you start the truck. If it has power, your GPR is energizing your glow plugs, if it does not have power, it is not.

Once the engine is warm or the temp gauge has moved off of the peg (approx. 100 degrees) you do not need to wait to start your truck.

 

I have one bad GP right now and the GP's still come on for a bit. Plow you know how warm it has been down here. My GP's still come on every morning and the truck misses till I get down the road about 3/4 mile then it clears up. I always attributed this to the bad GP. Hopefully the missing is not something that I am missing.