[NA] Starter won't crank without booster

[Jim K]

I have this junky old forklift:



It's a pain at times, but mostly does what I need it to do. Since sitting all winter, its latest trick is not starting unless I put the battery booster on it, or jump start it. "Bad battery" you say.... well the battery is one year old, tests good, and holds charge, but even right after taking the charger off of it, I just get "click, click, click, click..." Put the booster on it, it turns right over and starts.

I've not had anything act quite like this. Bad starter? Bad solenoid? Cables and ground look okay. Guess I should try jumping the battery straight to the starter terminal to eliminate the solenoid as a possibility. It seems weird that just a couple more volts would make the difference. Is it possible for a battery to have normal voltage, but not be able to supply any amps? It's a pretty big battery for a worn out little 141ci gas 4 cylinder.

 

[FancyG]

Have you given the solenoid a firm rap?

 

[Dana]

Check the battery voltage while cranking, sometimes it'll show full voltage under no load but drop down when there's any demand on it. I'm having the exact same problem with my plane right now.

 

[Bell206]

Put the booster on it, it turns right over and starts.

Sounds more like a bad/dirty connection(s). Check for voltage drops from the battery to the starter. Youtube has a bunch of videos on how to do it for positive and ground sides. The area with the drop should be your problem.

 

[Jim K]

Have you given the solenoid a firm rap?

I haven't tried percussive maintenance yet as it works fine at the higher voltage, but hitting it would be cathartic, so I'll do that next.

 

[Capt. Geoffrey Thorpe]

When you are connecting your booster battery - you connect it at the permanent battery? If so you are bypassing only the original battery and the connections between the cables and the battery itself - that should narrow down where you need to look.

 

[geezer]

The Captain has it, one of the cable to battery clamps is corroded. Common problem after sitting a long time.

Somewhat counter intuitive, after you clean the inside of the clamps, and outside of the terminals (Or mating surfaces if side connect), coat all surfaces with Vaseline or other similar light grease before assembling.
The grease squeezes off the surfaces that come together, and prevent corrosion where the metal does not meet. Moist air is the corrosive, and the grease keeps it out.

 

[Dan Thomas]

Measure the battery voltage after engine has started. Booster cables off, of course. The alternator might be shot and not charging the battery. You should see14 volts or so if the alternator is working.

 

[Jim K]

I think you guys are onto something. I didn't have time to really diagnose it today, and because we're in the midst of moving, my multimeter is being a bit elusive at the moment. I did however notice this while boosting it to get it going today:



I think that damage is probably from the booster clamps, but it certainly appears the booster is providing all the amps. I did whack the solenoid and loosen & twist the clamps, to no avail. When my meter makes itself known (I think it's in a box in the garage...) and I have time, I'll hunt down the source of the resistance. Right now it's a mad scramble to get things hitched up and ready to go to the field on Monday.

I appreciate the input!

 

[Racerx]

Battery. Poor terminals. Or the battery itself is tango uniform.

If the boy took your multimeter and didn't give it back, try and jump the solenoid.

Di-electric grease is your friend. It says silicone lube, but I wouldn't recommend it in the bedroom

 

[Ted]

Yeah, try new ends. That's probably your issue. May even be able to clean those up.