Sometimes when my truck sits overnight and it gets cold enough to require the grid heater to come on for starting the truck, it won't start.

I wait till the heater goes off, the audible click and the volts to rise back to 12, then it just clicks (solinoid trying to colapse) away till finally nothing.

I put it on a 12v 20 amp charge for 20 minutes and it starts right up.

If I drive it somewhere short distance (4-5 miles) turn it off then go thru the start cycle again where it needs the grid heater to turn on, starts right up. Will be fine for a few days
even if the grid heater is required,voltage reads good when driving. Then outta no where it does it again.

I'm sure deleting the grid would probably fix it but that is not the root of the problem.

Wondering if anyone has had this problem. Any electrical guroos out there that can point me in a starting direction?

 

how are the batteries? you might try replacing them and try that. one of them might have a internal draw or short that is sucking the other battery down when you try to crank it. batteries will show that they are good but when they have a load on them they will drop on there face if there bad. the grid heater should not draw your batteries down that bad. i would load test them each by them selves not together and see what you find. if one of them is showing bad then it will pull the other one down with it.

 

i kinda think it is a battery issue too.

 

yea test the batteries... if they are bad you wont really notice while you are driving or right after you drive somewhere so test em after they have been sitting for a while

 

I would guess the batteries too. I went through a similar problem with mine and finally just replaced the batteries and no problems since. Have them load tested

 

Disconnected one and read 12 volts on the other, started the truck. Reconnected battery and disconected the the one which started the truck, it read 8 volts. When i pulled it out the ends were very swollen, replaced with a carquest 65-70 with 880 amps, running fine and cranks over way easier. It happened so slow that i didn't notice over time that the truck was cranking slower and slower.
Thanks for the help.

Is the second battery just for towing and accessories, or does the starter need that many amps? Thought being, if it is only needed for towing and accesories that i would put in a marine battery disconnect and only have the second battery online for towing and heavier electrical load situations.

 

no it uses both batteries for everything. 880 amps seems low for a diesel battery usually you will have two 1000 amp batteries. dont use a marine battery on your automotive truck or vise versa they charge differently and its not good for them

 

not a marine battery a marine battery disconect, so it could be outside the vehicle. Thought being, i could turn it on when towing.

truck came stock with 2 750 cca bats

 

not sure, but I think all starter's are 12v for automotive side, the only time I have seen 24v starters, big rigs and military application.

the battery that is closest to the starter is usally the battery that starts it, or where the starter pulls most of the amp from, try switching batterys and see if that helps.

 

Already fixed batties are in parralel so the system is 12 volt, just has extra amps availabe for towing lights electric breaks, camper power, whayeber extra demands a normal vehicle would not see.