Engine/Transmission (1994 - 1998) Intake Heater Grid Problems

[MASanders]

Having a hard time starting the truck. Cranks OK, but doesn't seem to want to fire very well. I put a test light on the two studs on the heater grid while "Wait to Start" light is on. Nothing from the test light. I can't find a listing for a specific fuse. Is there one? I'm going back out to try and get to the relays. Been working at a NAPA for 3 years, and have never been asked for any of these (relays or heater). How common a problem? Thanks!!
I'm getting power to the relays from the battery. No output.

 

[B.G. Smith]

There are two heater grids, the two studs at the front of the intake are grounded and the two at the rear are connected to wires which come through relays and I beliieve they are located under the drivers side battery. If you are reading between the two studs at the rear you won't get a reading with the light, if the relays is working and closed you are reading across two 12 volt lines, if the relays are open and the grids are not burned in two you would get a resistance reading. You might be able to hear the relays click if they are working. I am looking at a 99 manual and don't see a fuse in the circuit, may be a fusible link. A volt/ohm meter would be very helpful for you if your trouble shooting if you can get your hands on one. bg

 

[DonFitzwater]

There is a fusible link arrangement under or near the drivers side battery. Test the solenoid operation first.

 

[Bob4x4]

A good scanner will give you the option to actuate the grids. That will make the diag much easier

 

[Axtell3]

I replaced my relays with snowplow relays, at a cost of 16 bucks. I got them at NAPA too.

 

[Cosmo]

The power on my 12 valve goes to the two studs at the front of the heater grid, rears ground. Fusible link feeds the two solenoids.

One of my solenoids burned out. Rockauto I believe has replacement relays for about $60. Elsewhere you can expect to drop $100+ on them. Or do what he did and use a non-case grounding solenoid - I've seen people mention snow plows, and also some starter relays.

 

[MASanders]

So today it starts (It's a little warmer out). I have to see if my older scan tool will work with the heater. Thanks for all the input, I still think I have issues, but I have a good idea on how to check things!!

 

[GAmes]

This might help. http://dodgeram.org/tech/dsl/troubleshooting/Maniford_htr.htm
I replaced my relays with non-oem relays. The stockers fail at an alarming rate.