Grid Heater not working - what to check

[John Berger]

I'm getting nickel'd and dimed to death with my truck lately. The grid heater stopped working. It's a warranty item, but my warranty comes with a deductible. Do I really need it? What to check? I'm a bit concerned with all of these potential electrical (wheel sensor, grid heater) problems popping up all of a sudden

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1999 Dodge Ram 3500 Quad Cab 2wd; 5 spd; 4:10 LSD rear; Mag-Hytec differential cover; US Gear EGT and Boost gauges. Stewart Warner Fuel Pressure Gauge with dual senders, Westach Oil Temp Gauge for differential. Rancho 9000's shocks, PowerEdge EZ Box, Amsoil foam air filter and synthetics in the motor and differential. Cummins Power, don't leave home without it

 

[Alan Reagan]

John, as warm as it is, it probably won't be working right now. That thing is temperature sensitive. The computer detects outside air temperature and engine temperature and determines when heat is needed. It's not getting cold enough to need grid or fuel heat applied. I can't remember what the threshold is for the temperature but I'll check. But if you need to check it, there are two relays In the PCM and a fusible link between the grid heaters and the batteries in the black wires. You could only check continuity up to the relays because if they are not energized, there will not be continuity to the grid. Also, be careful. If you switch the truck on and are testing continuity with voltage applied you may damage your ohmeter. Also, if you check the resistance or continuity of the grid, be sure and disconnect the wires or you will possibly read "back" through the system instead of the grid itself. Email and I'll fax you the schematic if you need it.

 

[John Berger]

Thanks Alan. I'm not so concerned with the grid heater as I am with not hearing that thump under the hood when I turn the key to run. I do not recall the "thump" not being there the last two summers. Maybe I just didn't pay attention like I thought I was. I'll give you a call this evening.
Later.

John

 

[Alan Reagan]

Correction, the relays are not in the power control module. Follow the six guage wires from your battery and you'll go right to them. Sorry for the confusion. Also, the temp is about 66* F for the heaters not to cycle. If you are in a closed garage you are probably doing better than that.

[This message has been edited by Alan Reagan (edited 05-22-2001). ]

 

[John Berger]

Correction. It's not the grid heater, it's the ABS system that causes the thump. Sorry for the confusion.

 

[RobbyRam]

Talk to Nowel(HVAC)! He's disconnected and removed his grid heater, and also the extra battery. He lives in Half Moon Bay, California where the temperature averages about 60 to 70 degrees.


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Y2K Awesome Black LB 3500 QC SLT, 24Valve ETC ISB, 4x4, 4:10 LSD, DTT Custom prepared Auto transmission VB, Power Edge 'EZ', DD2's, K&N, Polished Stull Billet Grill/Fog inserts, Chrome Smitty-Built Step Rails, Mopar Chrome-Tipped Mud Flaps, A-Pillar mounted West-Tach Turbo/Pyro/Trans Temp gauges, Rancho 9000's, Diamond Plated Tool Box, + a bunch of other stuff. Fact:The First Fords' had 'DODGE' Engines! The new PSD's need them!

 

[Evan A. Beck]

I added a couple of LED pilot lights for my grid heaters. No real reason for doing it, just thought it would be cool. #ad
I have found that both heaters are rarely on at the same time. They alternate every few seconds in proportion to engine RPM. The heaters do not come on above 18 mph.

I put the LED's where the auto trans trucks have the shift indicator. Great spot, looks stock! #ad

 

[Alan Reagan]

Evan, You are tooooo much. I like the idea of seeing when the heaters are on.

 

[MCummings]

Evan,,, You have any pictures of some of the gauges and lights in your truck?

MerrickNJr

 

[Evan A. Beck]

I'll see if I can get some pics... Email me, guys! #ad


Pilot lights, switches, and other gadgets are great... MORE = BETTER. #ad


BOMB ON