bad starter?

[madpogue]

Load test with the batteries connected tells you nothing about EACH battery separately. Disconnect one negative, to isolate them, then load test each one individually. You need to know if one battery is weaker than the other.

 

[mikepotts]

Load test with the batteries connected tells you nothing about EACH battery separately. Disconnect one negative, to isolate them, then load test each one individually. You need to know if one battery is weaker than the other.

Did that the other day and they both tested fine. Seems like the strter is putting alot more load on than my load tester can.

 

[BDCarrillo]

Can a few folks post up their cranking RPM to give a good idea what the "target" should be? I've read from 200-400

 

[nic55kel]

To identify if the wiring is the problem you need to measure the voltage drop from the battery positive to the starter positive when cranking. Should be not more than .5 volt.
Check the same again on the ground side, voltage drop between battery negative and starter case. Again no more than .5 volt.
The old chevy 350s were famous for poor cranking because of poor ground. Factory ran the negative cable to the alternator bracket.
If it were mine I would check the voltage drop from both batteries. Also check for any part of the starter circuit that is getting warm when cranking.
heat = resistance.
If all checks okay then that only leaves the starter as the problem.

 

[mikepotts]

removed both ground cables last nite and inspected. found the pass side ground had been rubbing the frame rail on one place, worn thru the jacket and was corroding, so the jacket was removed from the effected area, cleaned with vinegar and rinsed then rewrapped (no other choice at 11:30 last nite) with KV insulating tape left over from the mining days and reinstalled... the problem remains. im about to pull the trigger on two batteries today, i just hate getting into the "parts replacing" routine w/o a definitive answer to "why". thinking to myself, "what are the chances that i replace the batteries AND starter and the problem remains... have i overlooked something?"

 

[madpogue]

How much current does your load tester draw?

 

[mikepotts]

How much current does your load tester draw?

im not sure, its an old school one with the heater element for resistence. my dad bought it like 28 yrs ago.

 

[mikepotts]

i just saw this on another site and since im a little bit 'o redneck, im gonna give it a try and go with the results...

Ok, this is my old Redneck way of checking to see if it's a starter or Battery Problem.

Have a friend sit in the driver’s seat and you stand in front of the truck. Have them turn the headlights then crank the motor over.
1. If your headlights dim a lot while cranking, then it's the batt's.
2. If your headlights just barely dim while cranking the starter, then it's your starter.
Hope this helps.
JIM

 

[nj_m715]

unless the starter is bad but still cranking and drawing a lot more amps then it should draw causing your lights to dim due to the load on the batteries.

You tested the batteries as good, replaced or cleaned all the cables so I would go after the starter next not batteries.

 

[mikepotts]

unless the starter is bad but still cranking and drawing a lot more amps then it should draw causing your lights to dim due to the load on the batteries.

You tested the batteries as good, replaced or cleaned all the cables so I would go after the starter next not batteries.

im gonna see what that does, but im leaning toward the starter as well... if i have to roll the dice on a "repair", the starter is cheaper than batteries. i found it at pepboys for $109.99 lifetime warr. and they have a 25% off coupon code. i would rather spend an unneeded $100 than an unneeded $250.

 

[madpogue]

Rather than "roll the dice", you need more conclusive tests. Any FLAPS can load test the batteries. If you drive the truck in and have them test them in the lot, remember to disconnect one negative to isolate the batteries, no matter what the counter dude might say to the contrary. They should also be able to test the starter, but their component tests are only as good as the tester. If you can find one of those old-school shops that rebuilds auto electric components, where they still smoke and curse in the shop, their folks have a lot better "ear" for testing starters, alternators, etc. And if your starter is bad, a rebuild at one of these places will most likely outlast any "lifetime warranty" offshore reman cr@p at the FLAPS.

Harbor Freight sells a 100A load tester, $20-ish, that will at least give you some clue as to the condition of the batteries. For $50 you can get a 500A carbon pile tester that will put just about any battery through its paces.

 

[mikepotts]

Rather than "roll the dice", you need more conclusive tests. Any FLAPS can load test the batteries. If you drive the truck in and have them test them in the lot, remember to disconnect one negative to isolate the batteries, no matter what the counter dude might say to the contrary. They should also be able to test the starter, but their component tests are only as good as the tester. If you can find one of those old-school shops that rebuilds auto electric components, where they still smoke and curse in the shop, their folks have a lot better "ear" for testing starters, alternators, etc. And if your starter is bad, a rebuild at one of these places will most likely outlast any "lifetime warranty" offshore reman cr@p at the FLAPS.

Harbor Freight sells a 100A load tester, $20-ish, that will at least give you some clue as to the condition of the batteries. For $50 you can get a 500A carbon pile tester that will put just about any battery through its paces.

i had the manager of the local advance test the batts and starter with his tester... it showed everything being fine, he mentioned my truck had the lowest current draw he had ever seen (everything off) .01

all the old schoole starter/alt shops around here have long since been put out of business my the chains, i ordered a starter from pepboys.

 

[madpogue]

When you tested the batteries at Advance, were they out of the truck? Were they at least isolated as I described? Chain parts store is more likely to get the battery test right, and the component test wrong. So if it does come down to a roll of the dice, yeah, the starter would be the safer bet.

Did you do the voltage loss test as nik55 described? Are you sure that the ground cable that you found damaged, that it was just the insulation that was damaged and not the cable strands themselves?

Vehicles of our vintage have very little "keep-alive" current draw, compared to today's line-up. A very small amount for the PCM and the electronic radio, that's it. That manager at Advance is probably accustomed to testing newer cars with a gazillion gadgets that help the driver do everything except watch the road, all taking their toll on the battery.

Shame about those local shops. Same thing has happened with radiator repair, esp. with them all going plastic/aluminum. Knock wood, we still have a couple of old-school electrical rebuilders in town. Only way to keep the chains from kicking them to the curb is DIYers like us keep doing business with them.

 

[mikepotts]

yeah, i disconnected the ground on the batteries one at a time for him to test them seperate. in all honesty i didnt do the voltage loss test he described. im sure the cable itself is fine.

 

[ifrythings]

Starter diameter 4"
Amp draw Nom. 150-200A
Min. cranking voltage 9.6V
Engine rpm 180-250 RPM

Starter diameter 4-1/2"
Amp draw Nom. 150-180A
Min. cranking voltage 9.6V
Engine rpm 180-290 RPM

Do note that you maybe condeming a good starter that just has a bad pull in solenoid with burnt contacts, The way I test starters is with a clamp on current meter and testing the voltage to the actual starter motor, not the main battery connection to the solenoid, this elimates false diagnosise.

Have you made sure all the starter bolts are present and not loose causing poor ground from engine to starter?