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7.3 thread continued?

reptillikus said:
How long? The book isn't quite accurate - some of calibrations vary the time and some don't.
My old 96 PCM ran the glow plugs for a different length of time than my 97 PCM did. Both stone cold were 3 minutes, but the 97 would reduce the duration based on engine temp (once fully warmed up they don't cycle at all), whereas the 96 would turn them on for the full duration every time you cycled the key regardless of engine temp.
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I'm not sure, seemed like I waited 3-4 mins? I need to do some more testing, but was more concerned with other things.

reptillikus said:
I don't know how much current the grid heater pulls, but it can't be more than the glow plugs.
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That's what I thought, but depending where you read, it's 190-220 amps :eek:
 
Ok woah, that's a bit more than I thought! Did some digging and I see that Dodge was pulsing the power for them to keep from melting wires or relays.
www.thedieselstop.com

Dodge Cummins Intake Heater Grid ?'s

www.thedieselstop.com www.thedieselstop.com

Also mentions they turn the alternator off when the heaters are on to protect them.
 
Anyone know where this goes? I think I got the other vacuum hoses hooked up right, but can see what this would go to.
20240921_144907.jpg
20240921_144858.jpg
 
That's the washer pump line.

Be gentle with it, they like to crack at this age and it's always just under the cowl where you cant reach it to sleeve it with hose :laughing:
 
I think I found my cruise control problem. Sometimes I just randomly try it just because. Today it was raining and I hit the on and set button at 55 and it set. I drove about 5 miles then the speed limit changed and I hit accel up to 70 and it worked perfectly. Once I got into a town I had to kick it off with the brake and it reset after that. Then I had to stop at a light and it didn’t work again after that. I kicked the clutch pedal in a couple times and it worked again. The next light I could never get it to work again.

I assume it is the clutch switch. I looked under the dash and didn’t see a switch on the pedal. It must be underneath. I wasn’t going to lay in the water today to find out. I do know the truck wont start unless your foot is all the way to the floor on the clutch pedal so I assumed the switch was fine. Now im not so sure. Is there a way to bypass it, and would that make my cruise work assuming it is the switchs fault?
 
KungFooMASTA said:
I think I found my cruise control problem. Sometimes I just randomly try it just because. Today it was raining and I hit the on and set button at 55 and it set. I drove about 5 miles then the speed limit changed and I hit accel up to 70 and it worked perfectly. Once I got into a town I had to kick it off with the brake and it reset after that. Then I had to stop at a light and it didn’t work again after that. I kicked the clutch pedal in a couple times and it worked again. The next light I could never get it to work again.

I assume it is the clutch switch. I looked under the dash and didn’t see a switch on the pedal. It must be underneath. I wasn’t going to lay in the water today to find out. I do know the truck wont start unless your foot is all the way to the floor on the clutch pedal so I assumed the switch was fine. Now im not so sure. Is there a way to bypass it, and would that make my cruise work assuming it is the switchs fault?
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I think there is 2 switches because from what I remember the cruise will kick off as soon as you touch the clutch. But ya, I'd start there.

Does your brake light on the dash work? Like when the parking brake is on?
 
The manual and auto trucks use the same dash harness, the autos just have a bypass plug in the harness. So you could grab one out of a junkyard truck and plug it in to test.

IIRC there is only one switch on the clutch pedal but I think it cuts multiple circuits. I'd have to go look at the book again. On the diesel trucks the pressure switch in the master is the one that disables the cruise, not the brake pedal sensor.
 
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reptillikus said:
The manual and auto trucks use the same dash harness, the autos just have a bypass plug in the harness. So you could grab one out of a junkyard truck and plug it in to test.

IIRC there is only one switch on the clutch pedal but I think it cuts multiple circuits. I'd have to go look at the book again. On the diesel trucks the pressure switch in the master is the one that disables the cruise, not the brake pedal sensor.
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It uses the brake pedal switch as well. I don't have a cruise master cylinder (so without that pressure switch) and cruise that I added works fine.
I just had to jumper that plug.
 
Yeah that was the big recall on the gas engines. The diaphragm would fail letting brake fluid into the switch, shorting it and causing a fire. It's why they come with a fusible link now.

The gassers were fed by a fuse that was hot at all times, that's why people were coming home to their houses burned down. On the diesels they were fed by a key hot fuse instead.
 
I would like to just jump all the switch’s except maybe the brake pedal switch.

Right after I posted earlier saying the truck wont start without the clutch pressed in. I went out and it started without pressing the clutch in. I know for a fact it wouldn’t start the other day without the clutch pedal pressed. So it seems the switch must be sticking or shorting out.
 
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