Something I figured out the other day. I had started my truck cold after doing a valve adjustment and the grid heater was cycling in and out as normal. Then I placed my hand on the back of the alternator near the diode plate and Wow! that thing gets hot. Even with the Quadzilla bumping up the idle to 1,200 RPM with its own high idle the draw of the grid heater is considerable. 

 

I'm starting to think it might a be a good suggestion to replace my grid heater here in the future and see if the diode heat is reduced. 

The grid heater do not ground through the body. That is insulated by ceramic or something. The ground is the lead bolted down on the front side. The twin studs are your power leads. 

 

Typically the only time both grid heaters are hot is during the pre-heat cycle for 190 Amp draw. After the engine is started then it's typically only one element running for 95 Amp draw. (Thinking out loud and educated guessing) I wonder if there is a weird ground issue or problem where its possible for both solenoids to fire during the post heat cycle? 

 

 

Yellow/Black and the Orange/Black go back to the ECM and supply the positive signal to fire the solenoids. According to the Dodge FSM the G115 is a direct connection with the battery ground. Assuming on the driver side. Still in all, there is the joint connector in the PDC (weak connection, bad ground point?)

 

To get information correct. I'm going to have to test and see what lead (OR/BLK and YEL/BLK) does what during what time (pre or post heat). Verify my ground to the battery is good from point to point. (Solenoid to the joint connector and then on to the battery). Verify the voltage at the solenoid is actually 12V (which it should be). Then ohm test the grid heater as well to see what I get for measurement for @IBMobile .

 

@W-T gave us the ground wire mod now I'm going to get the grid heater fix. (or at least a good attempt too...)

What is the #6 or so sized wire that runs from the intake horn bolt down to the side of the grid heater body then? Or is my truck the only one that has it? I'll have to look closer and get a pic tomorrow. 

6 minutes ago, dave110 said:

What is the #6 or so sized wire that runs from the intake horn bolt down to the side of the grid heater body then?

 

Ground wire. 

6 minutes ago, dave110 said:

Or is my truck the only one that has it?

 

All truck have this one wire in the front that fastened to the grid heater mounting bolt. Yeah, its the ground wire. The two wires on the rear are the power wires from the solenoids.

20 minutes ago, Mopar1973Man said:

The grid heater do not ground through the body. That is insulated by ceramic or something. The ground is the lead bolted down on the front side. The twin studs are your power leads. 

 

1 minute ago, Mopar1973Man said:

 

Ground wire. 

 

All truck have this one wire in the front that fastened to the grid heater mounting bolt. Yeah, its the ground wire. The two wires on the rear are the power wires from the solenoids.

 

 

9 minutes ago, dave110 said:

What is the #6 or so sized wire that runs from the intake horn bolt down to the side of the grid heater body then? Or is my truck the only one that has it? I'll have to look closer and get a pic tomorrow. 

Now I'm confused. You say it's not the ground but it is.

I am with @dave110 on that one. I have the power coming into the grids on two posts on the firewall side and one ground off of the radiator side connected with one of the bolts on the in take horn. I see no other wires.

There grid heater technically is not grounded there it own body. The aluminum housing that holds the element. There is a single stud that passes out of the aluminum body and this stud is on the front side of the grid heater. Single lead looped around to the inside front mounting bolt. Being the gaskets between the manifold to the grid heater and the grid heater to the air horn there is no contact for ground. So to prevent arcing from weak ground this lead on the front is added to give a solid ground for the grid heaters. 

 

This is the ground for the grid heater.

 

The two studs on the back at the two power leads. 

2 minutes ago, Mopar1973Man said:

There grid heater technically is not grounded there it own body. The aluminum housing that holds the element. There is a single stud that passes out of the aluminum body and this stud is on the front side of the grid heater. Single lead looped around to the inside front mounting bolt. Being the gaskets between the manifold to the grid heater and the grid heater to the air horn there is no contact for ground. So to prevent arcing from weak ground this lead on the front is added to give a solid ground for the grid heaters. 

 

This is the ground for the grid heater.

 

The two studs on the back at the two power leads. 

That is the ground we have been talking about. Not the ground for the solenoids just the heaters. Am I missing something?

We'll get on the same page here after a chapter or two.

Just need brain food.

 

Seriously...??? 

Oh Yeah!! Didnt know they stuff chikin in a biscuit did ya?

Round here we stuff the bisquits in the chicken. That cereal looks good though. Do they sell that at the same store that has the synthetic blinker fluid?

48 minutes ago, dripley said:

Oh Yeah!! Didnt know they stuff chikin in a biscuit did ya?

                     I thought they stuffed chicken in a casket.

@IBMobile I’m interested in your grid heater switch. How is this coming? 

I'm waiting for it to be cold enough here for the final tests on it.   

2 minutes ago, IBMobile said:

I'm waiting for it to be cold enough here for the final tests on it.   

Awesome! Get me one when the tests are done! 

9 hours ago, Mopar1973Man said:

 

That is true if I unhook the grid heater the diodes stay very cool. 

 

Still, back the problem why did I get 10 plus years of service from the alternator with no issues. Now diodes are constantly overheating and failing? What has changed about the grid heaters to make the diodes overheat? Never had that issue with the truck brand new. 

 

Are you rebuilding your alternator or buying a rebuilt?

1 hour ago, NIsaacs said:

 

Are you rebuilding your alternator or buying a rebuilt?

 

Doesn't matter really when you realize that the very same diode I sell is most likely the very same diodes used in rebuilt units. Either install my diodes or get a rebuilt alternator with the same diodes. 

There is way more to an alternator than a diode. How much does it cost to keep rebuilding yours? Napa has a lifetime warrantee on theirs for $102. With that said, I keep my receipt close at hand. My oem died 1.5 years ago. It looked really nasty so I just got a rebuilt. I like the fact that no mater where you travel, there is a Napa close by.

20 minutes ago, NIsaacs said:

There is way more to an alternator than a diode. How much does it cost to keep rebuilding yours?

 

When it just the diodes that are failing the cost of the diodes. Never had brush failure yet. Then one case failure and one bearing failure. (OE alternator). The rest where all diodes failures last year 3 alternators during the winter time one only lasted only one month and diodes blew out. 

 

20 minutes ago, NIsaacs said:

Napa has a lifetime warrantee on theirs for $102.

I've burned up 5 of those. A couple did not even make it out of the store dead in the box. Ended up going to another store. Currently, I've got Autozone lifetime right now and it's holding up. Last winter when Installed this one I pulled the grid heater and it stopped the alternator failures for the rest of the winter. This last summer did the W-T ground wire mod.

 

Now, this winter I'm going back to using the grid heaters and seeing if I can figure this diode failure out. Eventually, the diodes will overheat and fail.

 

When you can fry diodes out of an alternator the only reason is high loads. The only thing with high loads is the grid heaters. Which I proved already if you leave the grid heater unplugged then the alternator failures stop. Like I've said in previous post why is my 1996 Dodge 1500 alternator which is 22 years old and never been replaced and OE yet still going? No high loads or grid heaters. 

 

I know Ibmobile is working on a grid heater switch that id Ca. EPA compliant where it does not throw codes.

Edited October 19, 20186 yr by Mopar1973Man