Stubborn Starter Problems CUCV

[shkira]

I posted this in the wrong place a couple days back so I am trying again...

I've seen on the site that people routinely have the same difficulties with starters. I think I've read them all looking for the Holy Grail. I am frustrated after 5 weeks of no CUCV and endless bills and still haven't solved the problem.

Everything worked great till bolt broke on the starter and had to replace the starter.

Since then...

Multiple fusible links, alternator rebuild, new battery, 4 rebuilt starters (2 unrelated sources), multiple starter relays (GM and Autozone). There is reference to a HD Napa relay but when I gave that number they told me the number crosses back to a blower motor not a relay.

No starter lasted more then 10 starts. Worst was 4.

Added new dedicated ground and cleaned up old grounds. Checked all wiring and no shorts, cracked insulation etc. Installed solenoid wire so no risk of it contacting main starter power cable. Also have traced wiring in the dash and in the engine compartment in the bundles and out -- no sign of anything wrong. Even changed the ignition switch and checked the wiring in the column to ensure no wire had worn through.

Typically would start a few times and then go back to the dreaded click. Last time started 10 times - key out of the ignition and it started to crank on its own till fusible link burned. After new ground, new fusible link and more tracing reconnected and fusible link burned again. I am now suspecting there is an internal short in the starter.

Is there a way to bench test a 24V starter?

Can it really be that I have gotten 3 bad starter rebuilds in a row?! The system is its original 24V and I wanted to keep it way. I am now seeing why people go to 12V conversions. Is it impossible to get a decent 24V rebuild?

I understand the common starter relay mod done but after 24 years of it working as GM designed it putting in a heavier duty relay would be compensating for another problem in the system. I could do that retrofit later but didn't have the problem till failure of the 1st starter. I want to isolate the real cause of what is creating this problem.

The vehicle was reliable till the stater failed mechanically. According to the MX records the previous replacement was done 15k miles back. They neglected to put the support bracket back on! If they had I'd not have this problem now!

I'd like it reliable again. What am I missing?

Thanks for your advice in advance.

This is what Michael responded with

You need to start a new thread with your question. This thread is for answers to common problems. Sounds like you have more than the common starter relay problem, but I think it still may be your main problem.

GM used a off-the-shelf heater relay as a starter relay in the CUCV. Its purpose is to take the 12 volt signal form the ignition switch and trigger the 24 v starter solenoid on the starter. Some of us feel that the original made in USA relay was just barely up to to the task and that the current made in China relays (along with aging problems in the circuits) are falling short. Some of the things you did sounds like a good idea and some of it was just throwing new parts at the problem. Did all of the failures start with a stuck starter relay?

 

[shkira]

Re: Stubborn Starter CUCV

Michael
Thanks for the reply. I am now starting at the TM and diagnosing that way. After reading the warning about the '85 relay defect in the TM I certainly understand the relay upgrade. Even though GM may have corrected the problem I have limited confidence that the Chinese manufacturers have the quality control for that tight a gap. Tearing the old relay apart certainly didn't fill me with lots of faith either! If not sooner I will head that way after I get this back to the way it was before the start of this mess. I want to replace with a HD 24V off the shelf part that I could readily replace if need be in the future.

This all started with a broken starter bolt and catastrophic failure of the starter. The first failed relay was newer (not corroded etc). Only had about 15k miles on it. I suspect that I fried the first relay in my repeated attempts to bang the starter and crank repeatedly to try to get it to turn over but it would just spin.

I really am just trying to get this thing back to the way it was. The Alternator rebuild was needed after one of the fusible links blew. After putting everything back GEN 2 light would stay on. Fried diodes and rectifier bridge . The battery was also a casualty I assume from all the fusible links also since it wouldn't hold a load after 18 hrs of charging. After 1st crank batt volt would drop to 6V. The ignition switch was to minimize any dragging or binding which might be causing relay arcing inside. Ground cable was to minimize any tendency also internal to the relay to arc. Other then that the starters were the only other things I changed.

In reply to Boner's comment I do not really want to butcher the original set up and go with the push start. I would rather keep those to deuces, 5Ts and airplanes! Although a nice looking button I think not tough enough for the 24V and high amp draw. Thanks for the suggestion though. If it continues this way though perhaps may end up that way!

Thanx for the feedback. Any thoughts on how I could have gone from normal to problems other then the common starter relay problem? I wasn't offroading I was just trying to get home from work!

 

[Michael]

First, I would leave the starter relay unmounted (it has its own ground wire) so you can unplug it if it sticks again, at least to everything settles down. I assume we are back to it started a couple of times and now it just clicks?

The two things that come to my mind are starter shims and the flex plate, neither of which I know much about. Are the starters not under warranty? What do they say when you take them back?

 

[mangus580]

Keep in mind, while it should work as designed.... the original relay is not rated for the amperage on it. That is why its common for people to replace them with something heavier.

You also might try getting your hands on a 'gear reduction' starter. www.odiron.com is one source of such starter.

 

[shkira]

Yes I was back to the couple starts and then click. The relay is hanging down and will continue to do so until it gets upgraded. I have been swayed! I will do that mod. I just want to select a good relay that will always be available in the future. So I want to get this back to normal and then do the refit. I am now waiting for another starter. I have been lucky so far but what is killing me is the several day turn around times and then getting to the swap out again. Hopefully by Saturday will have another one in hand. I understood that these are the gear reduction starters but have no way of knowing. Is there a way of telling by looking at them?

Someone did write on one of the posts that the only consistent change that seems to have led to the universal problem many have experienced is the conversion of the GR from the direct drive starters. Anyone else know what the difference is and how it may have influenced the systemic failures?

I didn't seem to have a problem with mating up to the flywheel. What can anyone tell me about the flexplate/shims? So never thought of any contribution to electrical gremlins?

Thanks all!

 

[Wile E. Coyote]

Make sure the shim's in place (even if the replacement starter says NO SHIM - in my own experience anyway), and make sure you have the radiator-end bracket installed and tight. Wherever you're getting the starters rebuilt, make sure the starter has a 24V solenoid installed and not a 12V one, as the 12V ones will work for awhile without a hiccup, but then will either just give you clickity-click or worse.

I always put the shim back in now after dealing with a number of replacement starters apparently binding etc. Haven't really had a problem since.

 

[tgtaylor64]

Can a 12 V starter be rewired to be 24 V?

 

[Wile E. Coyote]

The solenoid *seems* to be the only thing that needs to be changed, as when the 12V starter is used in the 24V setup, it seems to be the solenoid which fails after awhile. YMMV.

 

[aarron81]

the proper way to ship a gm starter is to install it without any shims and measure between the starter gear shaft and the flywheel teeth. it should be an 1/8". i use a 1/8" drill bit or welding rod with the flux knocked off. just poke it up in there between the teeth of the flywheel and starter gear shaft. if it doesnt fit then start shimming. also before putting the starter in check the deck on the block where the starter bolts up. if it is damaged or messed up in any way the block is junk and there is no repair. after it is shimmed properly you shouldnt hear much noise from the starter or gears.

 

[Warthog]

The solenoid *seems* to be the only thing that needs to be changed, as when the 12V starter is used in the 24V setup, it seems to be the solenoid which fails after awhile. YMMV.

The windings in the starter housing are different. Along with the solenoid.

A 12v starter will work in a 24v system for a short while. It will die a painful death.