CUCV non-starting

[Mastiff]

Hopefully this is a dumb/basic question. Went to start the M1008 today and all I got was rapid fire solenoid (I think) clicking. I normally associate this with dead batteries - the starter engages, then the voltage drops, the solenoid releases, repeat... So, I charged both batteries all day while at work. When I tried again tonight it did the same thing, but the solenoid noise is really fast and powerful, like a machine gun or something. The batteries seem good, without actually testing, both 12.5 or so volts, the combined set over 25 volts. Monitored it while my wife cranked and it went down to 19 or so.

Is there something else this could be, bad starter maybe?

I'm going to post on steel soldiers too, in case you watch both places.

 

[diesel4me]

I would guess the batteries are just junk,my 85 Suburban has 2 big group 27 batteries that were new in 2005 ,but after having it sit idle since I got it in the fall of 2009 and having to recharge them so many times,they just wont crank the engine over ,it may turn 4-5 times after I charge them,then all I get is the solenoid clicking like yours is doing...the batteries will accept a charge,and using jumpers hooked to another spare starter on my garage floor seems to whip it right over (with no load),but when I put them back in the Burb they act like they are dead,they just have no cranking balls left.....my guess is they have an internal short or bad connection between the cells that wont let sufficient amps flow to actually crank the engine over...

I haven't tried to swap 2 different batteries in the Burb yet to see if it really IS the batteries at fault,but I'm betting they are,but it could be the starter or cables are to blame too,because I did try using my other diesel pickup to jump the Burb and it still refused to crank much better,but the batteries could have been sucking all the juice up before letting any get to the starter too...I have had to crank the Burb over for several long periods before it would start,so it could be I fried the starter or the cables or they are gangrene inside,etc...but I bet its just the batteries..

 

[Mastiff]

Yes. I was poking around and happened to notice one of the batteries would take a minute or more to come back to 12.5 after being loaded. Replaced that one and back in business. Strange to me that even with jumpers from my running K5 on that battery it wouldn't turn over. Oh well.

 

[diesel4me]

I think what happens is one of the inter-cell connectors gets corroded or a cell simply refuses to allow enough current to pass thru it,so its like a semi open curcuit,and no matter how much amps you apply with jumper batteries,it wont get thru the bad battery to the starter...but I have noticed even if you take the cables off the dead batteries it still wont crank fast or long enough with jumpers to fire the engine up,I guess there is too much voltage and amperage drop in the jumper cables...even ones I have made of welding cables dont always get my diesels started especially if its cold out and they sat outside without the block heater plugged in..

 

[MrSchaeferPants]

Take the guess work out. Measure voltage @ starter while trying to start. Do you have power there, and how much. Your charger have a good high amp jump start position? If dead batteries were your problem, a good jump start should start the engine.

Load test and check gravity of batteries, only true way to see if they're bad.

If it won't start while being jumped, I'd start looking elsewhere. If it clicks, your relay should be good. Bang that starter/solenoid.