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Hey guys, owned freight shakers and 13 letter ###### spreaders all my life. Just recently bought a 23 year old 1990 379 short hood with a 3406B. I bought it cheap (less than 6 grand) so I knew it would have problems. I been working on them little by little and one by one. No sooner than I got it home this thing literally layed down and died. When it runs, it runs great. Any other time the ignition solonoid (not to be confused with the starter solonoid) will simply click/slam. I have put good batteries on it with no change. I have put a new starter and starter solonoid on it with no change. My next step was to replace the ignition solonoid and while painstakingly getting that off out from underneth the bracket on the frame I think I found the problem. Not the ignition solonoid, but an electrical part on top of the same flange with 3 heavy gauge wires to it and a cracked housing. This part needs to be replaced, problem is I have no idea what it is, what to call it or a part number to reference it. Maybe you guys can help with this by my posting a photo of it.
View attachment 50415

Think I found it - #30 on this schematic -http://www.supermiller.com/pdf/sk25762.pdf (379 schematic pdf)

 

No picture.
If you want help to identify this part,better repost the picture the correct way.

 

http://www.thetruckersreport.com/truckingindustryforum/attachment.php?attachmentid=50415


Think I found it - #30 on this schematic -http://www.supermiller.com/pdf/sk25762.pdf (379 schematic pdf)

I found the part...Its a thermal relay designed to cut the juice in the event of a overcharge etc...Has nothing to do with the starter problem...So the starter problem still exists...Learned today that if I short the two big posts on the solonoid to free wheel the starter and then go hit the start button the truck will bust over and fire right up. It's as if the bendix isn't making the trip to engage the starter unless the fly wheel is almost perfectly aligned...Which makes no sense since the splines on the bendix are angle ground to compensate for this.

1. All New Batteries
2. New Starter and Solonoid
3. New Key relay
4. Thermal breaker removed and bypassed.
5. Pulled the dash today and found no corrosion (surprisingly since this truck came out of Michigan and is salt eaten on the outside.)

Truck at times will still simply give a single click when ya hit the starter button (No change)...Only way to start it is to jump the starter and free wheel it first when it does this.

 

And that correct way would be?

 

Is it a puck looking thing near the starter on inside of frame rail. If so I delegated it on my 352. It is
like a power distribution block. Mine had a short and would shut all power off to truck.

 

Yes, correct. I eventually got my hands on a 379 schematic of the entire cab and chassis and traced it down that way. It's a 150 amp thermal circuit breaker used as a "main" for the alternator and cab fuse box. Three wires to it on two posts. One wire from the cab fusebox to post #1, One wire from the alternator on post #2 and one wire from the starter hot post to post #2. After figuring out what it was and it's purpose I just deleted it from the circuit by putting all three wires together with a bolt and nut and wrapping it with electrical tape for the time being.

The circuit breaker in question is Manufactured by the KLIXON division of Texas instruments.

The original part number is obsolete (CDLA-150) & 5925-00-775-1717 (Military Federal Supply Code)


The current part numbers I have found which crosses to it is:

CC31500 (Peterbilt)
SDLA-150 (Texas Instruments)

http://www.texasindustrialelectric.com/images/CDLA_120sm.gif

 

on a 1995 379 with low leaf air can yout put taller bags and make the ride height taller? or will it bind the driveline.

 

alright I will get it tomorrow