I'm fairly new to the diesel truck world and was wondering what these plugs are under the hood. The pics in the sticky aren't working. And what this thing under the driver side fender near the battery? The computer?

 

In first pic:
A and B are grid heater relay's
C is the vaccum switch
D, E, and F are the Auto-shutdown relay, starter relay, a/c clutch relay.
Not sure whats what on them, sorry.
Second pic, yes thats the 'puter.

 

F is the ASD relay (runs the alt field), D is A/C. Other than that, Curt nailed it.

 

I know D and F also control the grid heater. I just got done ripping out all that junk on my Dodge I couldn't take the birds nest any more. Externally regulated the Alt. and used the grid heater relays for headlight relays.



And here is what it looks like all cleaned up and rewired.

 

Neat !

But - what about your OD and tach drive ?
They come from the PCM I saw laying there withe rest of the stuff...

 

Well, I have a 5 speed so my OD works fine and I don't have a tach, so if I decide to get one then it looks like I'll be doing it the ol' skool way off of the Alt.

 

D and F have nothing to do with the grid relays, they run off the PCM.

Hot Dawg has an NV4500, he don't need no stinkin' PCM for his OD.

 

I know your prob. right but when I took the whole wire bundle apart both relays were wired right to the grid heater solenoids. ????? So......

 

The harnesses all run together but the relays are all controlled separately. So we're both right.

 

Then its a Win/Win.

 

Wow, that looks soo much cleaner than stock. I like.

 

I am all for that too... I think I could do it though cause I converted to a 47 rh and I am going to run the od and lock up off governor pressure... So I might be able to get rid of all that stuff.. so many things to doo

 

I'm going to convert to a 47rh soon as I get it built...
The probs I'm having now, I may yank everything myself. I've already installed a manual shutoff cable and a high idle cable, I've got a regulator to replace the one in the PCM ( preventative maintenance - replace it BEFORE it breaks ), and I've got a hall effect speed/rpm sensor that I'm going to install to read the flywheel teeth so I'll get more than 2 pulses per rev ( I think the reading will be a lot more accurate with 152 pulses per rev).

I just hate to give up my A/C and CC...And the A/C is only one line to the compressor clutch - relay wired to a switch..I've been wanting to 'refine' the controls so I can use the MAX position for heating and A/C.
NOW - how to get the CC going ??? Without running a cable !!!

 

Good question. I ripped mine out (it didn't work anyway) and I'm gunna put in a "Poor man's" cruise using a bike shifter. I like things mechanical anyway, thats why I drive a 1st Gen.

 

Are the grid relays rated for continuous duty? Seems like I read that they weren't at some point. Just wondering