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Slow starter issues and weird charging making you cranky?
Over the years I have battled slow starter issues on various machines. Most of the time it isn't the battery or starter. Once my F350 started to act up, this is what I did to cure it.
If alt is putting out 14 volts on the back of it with GPR engaged and RPM at 1500 you can assume the Alt is good.
Corrosion will create resistance, that resistance will block current flow and drop voltage to your starter thus turning it slower. The effect of corrosion on charging systems will be boiling your batteries and or not charging them up fully.
Lead corrosion is invisible, you have to scrape it clean with a blade type post cleaner like this one even on a new battery.
if you use them brush type post cleaners, you have to use them for like 20 turns back n forth in different positions like numbers on a clock, not just in one direction.
remove NEG side of batteries ( leave off until last part is done) and clean terminals inside and out and follow cable to block and remove/clean those connections until shiny too.
remove POS side of batteries and clean both inside and out of terminals and also remove POS from starter and clean up until shiny with wire brush and re assemble
On alt, remove large POS wire and inspect for burns/breaks and replace if needed. Clean both ends until shiny with wire brush and on both end of terminals and re assemble.
Remove starter and clean housing to block face and bolt heads surfaces to be shiny with wire brush.
Put on NEG cables after all POS are put back on.
If your starter and batteries are good, the starter should now see full power and crank fast like it used to.
After cranking and its slow still, check for hot as in temp on the connections you cleaned. Heat will tell you where the issue is. Cable and connections should be similar in temp with no hot spots.
If battery voltage drops below 10v when cranking even after fully charged, you could have a bad battery. Most truck battery places will load test them but not those car parts places can test at 900 amps load.
removing the alt wire should not make volts go up unless a short is inside of it but lets test battery too while here to rule it out Remove bat negs for safety
remove all wires on alt and tape that big cable up so it wont short
put on negs start charging batteries up remove charger when full wait 30 min remove one battery ground and measure volts on both batteries if not the same volts, your batteries are fighting and need new ones if the same, then alt diode might have a short remove both negs for safety connect alt big cable
put on negs wait 15-30 min and check temp of alt, if warm, its a bad diode inside
another test to run
Then charge both batteries up full.
run GPs for 2 min and remove Battery grounds
check voltage on both batteries
if not the same then the stronger one will charge the weaker one over night and you wont have much reserve power left
If you bought a new battery and using an old one too. The old one will pull down the new one. Always replace batteries as a set.
Upgrades:
I purchased this on Amazon as an upgrade as the original POS cable is only 1/0 on drivers side. this is 2/0 on both sides. bigger cable means more current and less voltage drop.
The 1999-2002 OEM starters are gear reduction also. The gear reduction assembly is inline with the starter motor, rather than offset from the starter motor.
I will add that whenever I do any work that involves the battery terminals I fastidiously reapply Permitex Battery Protector & sealer; Higt Tack spray works great too. I've never had an issue with terminals..
Great thread. MY old IDI had slow cranking issues even after a new starter. I replaced the positive and negative cables and cleaned the crap out of the terminals and block mating surface and it fixed it right up
Over the years I have battled slow starter issues on various machines. Most of the time it isn't the battery or starter. Once my F350 started to act up, this is what I did to cure it.
If alt is putting out 14 volts on the back of it with GPR engaged and RPM at 1500 you can assume the Alt is good.
Corrosion will create resistance, that resistance will block current flow and drop voltage to your starter thus turning it slower. The effect of corrosion on charging systems will be boiling your batteries and or not charging them up fully.
Lead corrosion is invisible, you have to scrape it clean with a blade type post cleaner like this one even on a new battery.
if you use them brush type post cleaners, you have to use them for like 20 turns back n forth in different positions like numbers on a clock, not just in one direction.
remove NEG side of batteries ( leave off until last part is done) and clean terminals inside and out and follow cable to block and remove/clean those connections until shiny too.
remove POS side of batteries and clean both inside and out of terminals and also remove POS from starter and clean up until shiny with wire brush and re assemble
On alt, remove large POS wire and inspect for burns/breaks and replace if needed. Clean both ends until shiny with wire brush and on both end of terminals and re assemble.
Remove starter and clean housing to block face and bolt heads surfaces to be shiny with wire brush.
Put on NEG cables after all POS are put back on.
If your starter and batteries are good, the starter should now see full power and crank fast like it used to.
After cranking and its slow still, check for hot as in temp on the connections you cleaned. Heat will tell you where the issue is. Cable and connections should be similar in temp with no hot spots.
If battery voltage drops below 10v when cranking even after fully charged, you could have a bad battery. Most truck battery places will load test them but not those car parts places can test at 900 amps load.
removing the alt wire should not make volts go up unless a short is inside of it but lets test battery too while here to rule it out Remove bat negs for safety
remove all wires on alt and tape that big cable up so it wont short
put on negs start charging batteries up remove charger when full wait 30 min remove one battery ground and measure volts on both batteries if not the same volts, your batteries are fighting and need new ones if the same, then alt diode might have a short remove both negs for safety connect alt big cable
put on negs wait 15-30 min and check temp of alt, if warm, its a bad diode inside
If you bought a new battery and using an old one too. The old one will pull down the new one. Always replace batteries as a set.
Upgrades:
I purchased this on Amazon as an upgrade as the original POS cable is only 1/0 on drivers side. this is 2/0 on both sides. bigger cable means more current and less voltage drop.
There is some great info in here that I fully agree with! I have been a HD truck and equipment mechanic for almost 40 years and you make some great points. I will go thru my normal troubleshooting procedures (which inlude a lot of your suggestions) and go from there. Havent really had time to do it at this point. Thanks to everyone who has tried to help out.
several years back my brother in law called me, his excursion wouldn't start, towed to a diesel shop, they couldn't get it running. towed home. towed to another diesel shop "specialized in powerstrokes" they couldn't get it running. he buys me airline ticket to Houston, picks me up at the airport we have some beers on the way back to his house put a battery charger on it, grill some good food that night with a cigar and some sipping whiskey afterwords. the next morning I get up go out to the garage remove the battery terminals and see the "porcelain" like corrosion on the terminals, scrape it clean on all 4 terminals. ( one of the shops had installed new batteries) and start the excursion. My sister walks out and is like WTF!
Great info. I replaced many of the mentioned components and noticed a huge difference when I put new batteries and upgraded lugs. I do want to upgrade my battery cables and the frame rail grounds. I read that the good grounding is important in many operations like the tranny, etc
Great info. I replaced many of the mentioned components and noticed a huge difference when I put new batteries and upgraded lugs. I do want to upgrade my battery cables and the frame rail grounds. I read that the good grounding is important in many operations like the tranny, etc
Check the positive cable. On the passenger side terminal the lead corroded around the copper cable. I bought a solder on lug. No more voltage drop.
11-22-2016, 10:08 AM
Slow starter issues and weird charging making you cranky?
