Flickering lights when glow plugs cycle?

[Puller]

After the wait to start light goes out and you start the truck lights flicker along with the voltage gauge. Any idea's on what is shorting out or going bad. It quits as soon as the gp's quit cycling.

 

[OLDBULL8]

The GP's cycle ON/OFF for up to 2 minutes after the initial cycle, sounds like bad batteries to me, or alternator is not putting out at least 14.5 volts after starting.

 

[DragRag]

Your description of what happens during your glow plug cycle sounds normal to me.

 

[Dieselcrawler]

yep, sounds normal. my 94 does it also. both batts and alt are good.

 

[Puller]

I have never seen this on a diesel before, I have seen them dim on and off with a slow constant draw from the gp's or grid heater but this is more like a quick flicker (much faster than a blinker on\off cycle so much so the voltage gauge jerks around). Bad batteries will cause this? They are a little weak but start it in 20 degree weather. It does have an original alternator on it. I will take a quick video in the morning for you guys to access.

Thanks

 

[racer30]

Check battery cables and chassis ground conections. sometimes its as easy as that. and it dosn't cost anythig but time.

 

[DragRag]

My volt gauge jerks on all my idi's when the glow plug controller is cycling. I still think you are ok. It is faster on some then others depending on how many glow plugs are burned out. The faster it cycles, generally speaking the more glow plugs you have burned out. Ohm out your glow plugs and see if some are bad, that wil slow the cycling down, but you are never going to see the volt gauge not bounce when they are cycling.

 

[Puller]

Here is a quick video of what I think is a problem.

http://www.youtube.com/watch?v=5jfCR6bQEwQ&list=UUL4sFcWLxbmHvl1-51asW6g&index=1&feature=plcp

Normal or not on these trucks, I've had 4 other 7.3's (PS though) and they never did this. I can't remember if my two 6.5's did this, they ran all jacked up when cold but I don't recall any flickering.

Will be changing the man positive wires on both batteries as soon as time allows, along with some nice mods just need time.

 

[OnDaRoad]

Normal .....

Here is a quick video of what I think is a problem.

http://www.youtube.com/watch?v=5jfCR6bQEwQ&list=UUL4sFcWLxbmHvl1-51asW6g&index=1&feature=plcp

Normal or not on these trucks, I've had 4 other 7.3's (PS though) and they never did this. I can't remember if my two 6.5's did this, they ran all jacked up when cold but I don't recall any flickering.

Will be changing the man positive wires on both batteries as soon as time allows, along with some nice mods just need time.

When you turn the ignition key to the ' ON ' position,
12VDC is sent to the glow plugs thru the controller,
when the resistance thru the circuit senses the plugs
are hot enough to ignite - the relay ' CLICKS ' on and off

If all of your glow plugs were not replaced at the same time and/or
you have a bad connection at the wiring harness connector,
the cycle will not complete - you will be cranking with
(1) or more cylinders not having heat to ignite cold fuel

Some guys cycle their glow plug circuit twice before starting .....


Jim

 

[liddledoggie]

i watched your video. thats how both of my trucks start. looks normal to me. joe

 

[Puller]

Alright then I leave it be for now, I know there's a few glow plugs not working but it can wait I don't use it everyday and it always at my house anyway.

Now I need to work on the air getting into the lines when I'm pumping fuel from the back tank, she smokes a little and has a miss at an idle. When running off the front tank it purrs like a kitten.

 

[Goofyexponent]

Mine does the EXACT same thing. I think she is normal!

 

[Cincinnati Guy]

Its normal. When cold the glow plugs may sometimes do whats called an after glow to get things up to temperature. When this is doing this take note of the power it draws by looking at your voltage gauge. Yes its bouncing all around as the plugs come on and back off. With all the draw it takes to power the glow plugs it in turn will take away a little power from other sources like your headlights.

 

[Drew2010]

yup. perfectly normal. my 90 did it with the old engine and the 94 engine... GP's take alot of juice.

On a side note, does your high idle not work or did you not push the pedal?

 

[OnDaRoad]

Where have I seen that truck in the Avatar before ?

i watched your video. thats how both of my trucks start. looks normal to me. joe

Joe ...

The truck in your avatar looks mighty familar .....