Adapting Glowplug Controller for Grid Heaters

[britannic]

After scouring the TDR, it seems the grid heaters are controlled by a PCM.



My truck glowplug controller works really well; it's fed a signal from a cylinder head water temp. sensor and also a glowplug inhibit switch that directly reads the cylinder head's latent heat.



I'm thinking about using the Dodge grid heater relays and connecting their trigger grounds to my GP controller.



The question mark is the IAT sensor and whether it would be suitable to signal the GP controller.



Any ideas will be much appreciated.



Would it be easier to attempt adapting a PCM?

 

[Philip]

Good questions on this. Let me throw my two cents worth in.



The Cummins head has a port in the head to install both sensors you will need. But what I am wondering is would you burn up the grid heater. Most of the trucks that used glow plugs seemed to hold them on longer than the Cummins ECM does in cold weather.



The last truck I drove with glow plugs was a 95 Ford F350 Crew Cab. On a 0 degree day. It would hold the glow plugs on for about 2 minutes. Where my 93 W350 Dodge will only hold them for about 30 seconds.

 

[barbwire]

I think it's great that you would take the time & $ to do this.

But I do not know why you would want another headache After all, I know that the grid heaters cycle a while after started, but I have never heard of them really hurting anything.

 

[britannic]

On the military pickup, the controller is set for 18 seconds with approximately a 60 second repeat cycle, which is only triggered if the inhibit switch hasn't reached 95* within the cycle time.



So, I may be on the right track with this - I really don't to have to hook up a PCM, just for the grid heaters.

Originally posted by Philip

Good questions on this. Let me throw my two cents worth in.



The Cummins head has a port in the head to install both sensors you will need. But what I am wondering is would you burn up the grid heater. Most of the trucks that used glow plugs seemed to hold them on longer than the Cummins ECM does in cold weather.



The last truck I drove with glow plugs was a 95 Ford F350 Crew Cab. On a 0 degree day. It would hold the glow plugs on for about 2 minutes. Where my 93 W350 Dodge will only hold them for about 30 seconds.

 

[britannic]

Also, the GP controller has an afterglow function that kicks in, if the cylinder head water temp doesn't get to temperature within a specified time and the GP inhibit switch doesn't activate. This only happens in very cold temperatures to prevent misfiring etc.



I believe this would be fairly close to the Dodge PCM's functionality.



I'm still open to suggestions though ...

 

[britannic]

I need to do it, since this is a conversion and I won't have a control system for the grid heaters otherwise. I really don't want to have to hack a Dodge PCM to get the intake heaters working, when I already have an excellent GP system that can probably be easily adapted without any wiring changes.

Originally posted by barbwire

But I do not know why you would want another headache After all, I know that the grid heaters cycle a while after started, but I have never heard of them really hurting anything.

 

[barbwire]

Oh, I see

I guess I should have waited to know more on the issue, before responding

 

[REakin]

Originally posted by britannic

I need to do it, since this is a conversion and I won't have a control system for the grid heaters otherwise. I really don't want to have to hack a Dodge PCM to get the intake heaters working, when I already have an excellent GP system that can probably be easily adapted without any wiring changes.

If you allready have everything you need to make it work you should give it a shot. I'm going through the nightmare of tearing through a dodge computer out of a 93 right now. (I quit on it though, the trucks too fun to drive!)

 

[Philip]

Looks like the programing for the old glow plugs should work. You might have to cycle it more than once like the 1st gen drivers have to on a real cold day.



If you do not have the relays. Check this thread out. It has aftermarket part numbers for the relays the 1st gen's used. This you can not get from Dodge anymore.