Basic non-start diagnosis help...

[Sam27]

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? Or should I just take the batteries out and have them tested? I also tried starting with jumper cables on one or the other battery from my blazer (not both at once). It doesn't seem like batteries.

 

[cpf240]

I'd say pull them and have them load tested.

 

[Warthog]

Bad cell in one of the batteries.

 

[Triple C]

Start simple, make sure your cables and connections are good.

 

[Sam27]

Bad cell in one of the batteries.

Yup. Strange because the chargers thought both batteries were good, and even with a running vehicle jumped to the bad battery it would not start. I just happened to notice that after loading the batteries, it took one of them a minute or more to get back to 12.5. Replaced that and all is good. Thanks for the replies.

 

[Warthog]

As the manuals state, (and I preach) whenever you are working on an weird electrical issue, start with fully charged and loadtested batteries. Don't assume they are good, even with new batteries. I have seen new on the shelf batteries that where bad.
Glad you found the issue.