Slow cranking- Long Post

[jrjuday]

My 93 W-350 started having occasional problems with slow cranking about a year ago, especially during cold weather. The battery was old, so I replaced it with a group 31 ( about 1100 CCA) which seemed to cure the problem for a while, but this fall the old slow crank issue returned. I replaced the pos. battery cable and cleaned the grounds, but the problem got so bad that by Christmas I was having to boost or jump the truck whenever the engine was cold. Finally, I ordered new starter contacts & brushes from Larry B. My son , Josh, yanked the starter while I was at work, installed them , and delivered the truck to me. (Great Kid!!!) But... I had to boost the truck when it was time to go home. The next day I replaced the ground cable. . NoGo. . Swapped in a known good battery... No luck... Switched starter relay with one of the other relays... No start. Finally, I installed a brand new starter relay I just happened to have, and it started right up. It"s too soon to tell if the problem is solved, but so far, so good. I guess the point of all this rambling is this: it may be a CTD, but it's wrapped in a Mopar, and starter relays have always been a booger in Chrysler products, so if you start having cranking issues, don't overlook that little black box on the fenderwell.

 

[GIT-R-DONE]

Do you have any pics of the starter relay that you changed out? Not sure if you mean the black box, (engine computer) or something else. I believe the 93 has the voltage regulator and such in the engine puter, behind the battery. Keep us posted as to how things are going.

 

[jrjuday]

Started my truck this morning at about 15deg. F; fired right up. There are three relays bolted to the driver's side inner fender in a row just aft of the horns; black, about 1" cube with a mounting bracket. The front one is the fuel pump relay. The middle one is the starter relay. The rear one is the A/C compressor clutch relay. Another post referred to switching plugs from one relay to another to test, but that did not work for me. Just a word of caution; the brushes in my starter WERE toast. Just changing the relay might have improved the starting, but might have masked the brush problem until further damage had been done to the starter. The starter is not easy to remove, but it is easy to disassemble, inspect, and reassemble. I highly recommend the Larry B contacts & brushes; good fast service, and a NEW starter will set ya back $400. oo+. Rebuilts are cheaper, but you get what you pay for. I'm going to get a starter relay & a fuel pump relay to keep in my travel kit!!

 

[dpuckett]

Not to nitpick, but I didnt think we had a fuel pump relay in our mechanical diesels.



You can get just a plain jane 30amp relay with the same hookup terminals and pattern as the OEM unit, just lacks the bracket, for under $10.



Daniel

 

[jrjuday]

Daniel; You may be right, I think I've heard that referred to as an auto-shutdown relay (?). But, fig. 18 on page 8w-22 of my fsm has it labeled as a fuel pump relay. Wouldn't be the first time i've seen a misprint. I'd like to know what actually is and what it does. Where are the good deals on relays. I got mine at NAPA for a different application and don't remember what it cost.

 

[RedRamAndy]

Thought I'd tag this onto a thread already started. My truck started cranking slowly a couple weeks ago. It has a 1 year old battery and new cable ends. The charging system is doing its job well too. So, I ordered a set of solenoid contacts from Larry Buck's. I've had to change those contacts before in other MoPARS for slow cranking or no-start condition. Got them and installed. No better. I figured the last weak link would be starter brushes. I pulled the starter again and took the cap off the motor to check the brushes. There was more rust on the brushplate than I would like to see. It turned out that one of the brushes was very stuck in its guide. After some disassembley, beadblasting, teflon coating and reassembly, this starter really spins! There was still a LOT of life left in the brushes on my 183k mile truck. One had just taken a vacation thereby dropping the start amperage feed by 50 percent. I wanted to post this since it's possible that you too can fix your starter for free.

 

[Greenleaf]

I have had many a starter for a 5. 9 to the starter repair shop. They have yet to see one that is worn out. They do get dirty and sticky as the brushes wear down and coat everything with that gun powdery dust.



The contacts do need a cleaning time to time and it is a good idea to test the armature for shorts.



My starters go bad in the buses when the driver cranks it too long in the winter. They are supposed to plug the thing in, but they are lazy. So, come Monday A. M. they crank it. and crank it. I have them burn the starters up so badly that the wire harness touching the starter motor body will melt!





My two trucks still have the original starter motors. You can buy the cheap knock off brands for about 200. 00, but it won't be a denso.



I just had a denso starter explode! I don't know what happened. The armature blew apart like a hand grenade. The drive said she couldn't get the bus to start (it was not plugged in) and then nothing.



I have it apart now and will try to post up some pictures of what remains.

 

[Greenleaf]

$518.00 mistake

Denso Starter. From an '07 model year

 

[MMeier]

Did you congratulate her on a job well done ? :-laf

 

[R C Cola]

Starter exploded

You got a quick laugh out of me on the "Job well done"

 

[JLEONARD]

You got a quick laugh out of me on the "Job well done"

Me too.

Then I got to thinking that Scott would save time and the scholl system's $$ if he would plug in all the busses every night. :-laf

But then he wouldn't have those cool photos to share.

 

[RedRamAndy]

WOW Greanleaf! That's amazing starter carnage. Seems like some genius could to come up with an intermittant-wiper type circuit interrupter on the trigger side of the solenoid to prevent such irreverance?? I'm not that schmart though. . Ouch! Funeral for a Denso...