Engine/Transmission (1994 - 1998) greetings 12 V'ers!

[Wyomingcowboy]

I am a visitor from the 24V side and had a question for a friend. She has a 94 and was explaining a problem that sounds alot like the heater grid cycling on and off. She went for a drive and then it started again. That only happens with a 24 v I thought?? Am I off track or is there something else?

 

[DieselNasty]

Do you mean the grid heater cycling on and off wile sitting and the lights dimming/ lowering rpms?

 

[Wyomingcowboy]

That's exactly what I am talking about. I thought it was only in the 24v? It is meant to help with emissions, and usually kicks off after 15-20 mph.

 

[Oil Burner]

You might be right. My 24v did it but my 12v doesn't.

 

[Simplysmn]

my 93 did the dimming of light's till it got higher in rpm's then alt was charging enough you didnt see it through light's

 

[Mokerz]

both of my trucks do that when it is cold, the 24v will adjust the idle some and the 12v just drops a few rpm then speeds up when they kick off. I replaced batteries in both trucks with 950cca's made for big trucks, that seemed to help a lot with the lights dimming. had to modify the battery holders to get them in though.

 

[hsmith]

Normal for the 12 valve, but with no idle compensator rpm's drop a tad each time the grids cycle.

 

[Missouri Mule]

Wyomingcowboy, don't know if it is for emissions but it definitely to warm the air going into the cylinders so the engine runs smoother quicker.

 

[Wyomingcowboy]

I have seen countless discussions on the 24v page about this. It is meant for emissions and that is why they come on below a certain temp. and stay on until a certain speed. I also found some instructions to bypass them by-way of an oil pressure sending unit. Lots of different thoughts on why you would want to do this, but my reason is because it drives me nuts! Search 24v for grid heater disconnect and you should find it.

 

[Joe G.]

The grid heater is to help start in cold weather. There is no way it's going to affect emissions after the engine is warm. I have started my '95 in cold weather without waiting for the grid heater. It started but it banded around and complained until all six were working right. There is no reason to be concerned about the short period of voltage fluxuation. The grid heaters draw 90 amps so it's no wonder the lights dim.

 

[Champane Flight]

Not a problem

It will cycle grid heater until ambient air temps entering engine raise. This is at manifold.

 

[Dfuruness]

I own one of each and they both cycle when cold.

 

[DieselDoghouse]

I've put 230K on my 12V and the heaters have always cycled:



when the ambient temp is below 60°F for:



3 minutes after startup

or until road speed = 18 mph

or engine speed achieves 1800 rpm.