Glow plug light is not coming one/ no start

[cowboydeane]

I have a 99 7.3 that the glow plug light is not working. It was blowing the fuse until I replaced the fuel heater. Unfortunately I broke the fuel heater thermostat (wif probe) while I was working on it. $300 later I have replace both parts, but still no glow plug light and no start. Can anyone help me?

[atvrider93]

I'm not 100% but I think a bad GPR can do that. could just be the light itself. what does happen, if anything? any clicking? maybe fuse?

[NoRalPh]

The lack of the WTS light is an indication the PCM is not running.

Make sure ALL fuses are OK, it sounds like it's still not powered.

[cowboydeane]

Thanks for your suggestions. I have checked all the fuses and replaced the one that was bad, still no power. The engine will crank, but will not fire. The truck was warming up one morning and it just quit. The light worked until then, but has not worked since then. Is there a relay somewhere? I am not much for diagnosing (more of a R&R guy), so anything you can tell me would be great. Including what is a GPR?

[Cutty72]

GPR is your Glow Plug Relay.

[GIMAMMOTH]

it should start with a bad GPR my 97 has been bad for years.. check your IDM.. or your crank sensor..

[cowboydeane]

I checked the GPR this morning. I have juice coming in, but not out. I will look to replace it, but there are two solenoid looking relays on top of the engine (I tested both). Which one is the GPR?

[NoRalPh]

It's not your GPR, if this was the winter the lack of a good working GP system could account for a no start, but not in August

It should certainly start, just might be a long crank without Glowplugs (I include a relay pic anyway...)

The PCM controls the WTS Light Not the relay....

I think your PCM is not running for some reason and that will give you both a no light AND no start situation.

Can you get a scanner on it to see if the computer is communicating?

Do you have power at the OBD-II connector? or cig lighter?

Is your truck stock? Does it have a chip installed?

Has it been raining lately? Is there water at the fusebox from above?

You're sure fuses 30 & 19 have power on both sides?

[cowboydeane]

Thank you very much for the picture. I have wondered which was the GPR for a long time.

Unfortunately I don't have a scanner.

I did test the cig lighter and there is power. I am affraid once again yall have me (I don't know what the OBD-II is), so I can't tell you if there is power there.

My truck is stock without a chip.

I am a youth minister, so I am out of town most of the summer. This truck has been down since May because I have been out of town and have not had time to work on it (they tell me I have to earn my pay in summer cause I don't work all winter lol) and today is the first rain I have known about for weeks.

The fuse box looks dry.

I did go back and look at fuses 19 and 30. 19 was good, but 30 wasn't even there. So I put a 15 amp in there (not sure what should be) and the WTS light started working. Unfortunately still no start though.

Thanks again for all of your time. I wish I had found this sight in May, I might have had my truck this summer.

[NoRalPh]

OK, sounds like progress

First, do you have the Owners Manual? If so, look to see what the fuses are and maybe for anything else missing...

Next, the OBD-II connector is what the scanner plugs into and is located somewhere below the steering column but, now that the PCM is running it's not something I'd bother with yet.

So, now there's something still not right..... but, the truck's been sitting for a while - right?

How are the batteries? Fully charged? (it will NEVER start if it's not cranking normally)

Fuel, is the filter housing full? Can you see fuel coming from the water drain if you open it? When you first roll-on the key do you hear the pump running for a couple of seconds? (on the frame rail below the drivers seat)

Oil, believe it or not , the truck is designed not to run if the engine oil is too low.

When you're cranking does the tach needle come-up a bit?

I'm puzzled by the missing fuse,,,, what happened? You said the heater was blowing the fuse, but what fuse was that if not #30? (maybe you just got mixed-up and put the replacement in a different place?)

At some point, if everything else looks OK, you've just got to get a scanner on it to look into what's causing the no-start. Unfortunately, it's a "special" scanner that not everybody has and you'll need to seek out someone with the right equipment. Often a local member can be found who can help you depending on where you are.