Engine/Transmission (1994 - 1998) grid heater not working

[DBranzovsky]

I should have been more clear with the problem with the grid heater on my '96 Ram. The truck has been hard starting. I noticed that the voltmeter wasn't measuring a draw. Inspecting the system per shop manual I found that the grid is okay, the cables from the relays are okay, and the relays are allright. Jumping the trigger wire from the pcm energized the grid. Now I'm thinking I need to trace wires back from air temp. sensor, as the sensor checked out okay with an ohm meter. The wires to the air temp. sensor check out at 300 ohms. Anybody have any more ideas. Don

 

[DMC]

Where are you located Geographically?



I am somewhat surprised that your grid heater should even cycle in July. The wait to start light always comes on, but unless your air temp sensor detects that the air is cold, It doesn't preheat. After you start your motor in cool weather the grids will cycle until the intake air is above 59*.



If you are in a region that is above 59* at start up, and you are having starting problems the grid heater isn't going to solve it.



Have you replaced your fuel hoses yet?



Sounds like you have a fuel problem.



Good Luck



Don

 

[DBranzovsky]

The pickup has always cycled the heater no matter what temp since I had it. I would think that it is a fuel problem too, except that when I get it running it runs fine. When the engine is at running temp it will start right up. Any thoughts Don

 

[DMC]

Ok, let me establish something.



What is the current air temperature when you start your truck?



Does your voltmeter cycle down to about 10-11 volts after you crank up your truck all the time? Ussually this only happens when the intake air temp is below about 59*. In very cold temps the grid heaters will cycle several times.



If your truck is doing this, then I would think that you need to check your intake air temp sensor.



Let us know how it goes.



Good Luck



Don

 

[Vaughn MacKenzie]

Let's discuss cool air induction in January

People . . . it's JULY, it was 103 today, and I'm reading a thread about GRID HEATERS???



Vaughn

 

[DBranzovsky]

Well this is Minnesota and it is not 103, Thank God. Last night i jumpered the pcm trigger wires and fired up the grid. The truck popped right off, so I know the problem is still grid related. I agree with you all that the truck shouldn't need grid when the temp is 70 degrees but it has always needed a little "kick". So has the pcm been dicatating wrong input output all these years.



One thing I'm curious about is this problem started with a very small problem. Last winter when I really needed the grid it would cycle okay but stall right after startup unless the operater would keep the rpm's up to say maybe 800-1000 for more or less 30 seconds. Sooo was that an air temp sensor problem coming on, remember on one of my last posts I said that I checked out the air temp sensor. So do I have a problem circuit to the pcm or is it the pcm. Any pcm guru's out there? Best Regards Don

 

[Joe G.]

Is your truck a manual or automatic transmission? What is your idle set at?

 

[Keith1]

mine ended up being the wiring going to the sensor right at the sensor the harness was pulling on the connectors and eventually broke one of the wires.