Hi all!

Here's a strange problem: Sometimes the starter motor will only crank really slow. Well, didn't sound strange enough? Here's the full story:

Truck is a -95 K2500 with batteries and alternator and belt all new - in an attempt to cure these anomalies.

Symptoms began with the voltmeter dropping from 14V under normal driving conditions to what I can only estimate is around 12 on the guage. It would sit there for a while and then pop back up to 14 every now and then. The drop in voltage is not a faulty meter as just breaking and using a few watts to the tail lights would make my headlight go dim. Strangely enough the drop often came on a down hill slope, and after a few minutes of driving. So away with the old batteries, the alternator, but no joy.

Batteries have charged reasonably fine anyways, the battery cables are clean, most of the plastic is removed from the terminals to acheive good connection.

But now it has moved a step further and most of the times - cold or warm - the starter will only crank very slowly, sometimes drawing so much current that the stereo shows it's "Hello" message as if just installed and power connected for the first time.

It will start however, but sometimes I've aborted the cranking immediately, opened the hood and pulled on the positive lead to the starter. Then it will crank normally, show 14volts and away we go. Sooner or later the voltage will drop again and If I stop to crank, it's slow again.

I just briefly looked under the engine only to find a bird nest of wires around the starter solenoid. The main leads seem to be securely fitted to the solenoid. The other single lead wires, I think there were two of them, might go to the glowplugs but I couldn't really tell.

So what is going on?? Could there be a short, just enough to draw an aweful lot of amps but without burning a fuse or indeed the entire cable? Could something in the solenoid draw current without engaging the starter motor, cuz you would here if the starter engaged. But why does pulling on a firmly secured battery cable help out??

This winter the starter would occationally slip also, so I'm concidering replacing the unit anyways. Is that a quick job by the way?

So did anyone experience anything like this before? Any hints appreciated, and yes I have already ordered new battery cables as well - but that does not solve the mystery. I believe something apart from the starter draws abnormal current when the started is engaged. It's not a permanent short in the system as the batteries don't drain after sitting weeks at a time. And it won't blow a fuse anywhere. I've tried to pull fuses when the truck runs at 12 on the guage to see if I can relieve load but still haven't figured anything out - apart from that if you pull the Ignition fuses the engine stops :p:

Well, this has puzzled me for at least two years, but the starter problem just begun a few weeks ago, and when the truck doesn't start I don't like it very much. Nor does my significant other, or the horses in the warm trailer... A lot of the threads here I noticed featured various guns for the final truck kill. I'd have to go for my Beretta 92FS with FMJ's....

Thanks!
/Jes

sometimes I've aborted the cranking immediately, opened the hood and pulled on the positive lead to the starter. Then it will crank normally, show 14volts and away we go.But why does pulling on a firmly secured battery cable help out??
Thanks!
/Jes
New battery cables :grd:

You say battery cables have been replaced BUT does that include all the cables underhood that run from battery to somewhere..ie both grounds, battery to starter, battery to battery??
Sounds like something is losing connection if you have to "pull" on the cable to get it started. Maybe a bad terminal post on the battery. Next time this happens get your Volt meter out and check voltage before your do your pull fix thingy.
I also like to use dual post batteries myself, These allow you to check voltage at the another post and check for bad connections. I also try to go with 0 sized cable with top post mounts when I replace cables.

I don't think he said he replaced them bowtie, just that they were ok and clean and that he had ordered new ones. I'll bet when he puts the new ones on his problems will go away.

Hi again!

Thanks for the quick replies! Quite right, cables are not new, only cleaned down to molecular level... But sure, I realize that corrotion can creep deep deep down under the plastic.
It might me an issue involving two separate problems. I just mix em up?
Just tell me please, does everyone drive around with 14volts on the meter at all times, except when glowplugs warm up, or the quick dip as the high beams go on?

I believe I've checked all battery cables and ground wires.
Thanks again for your inputs. I've had the truck for quite some time now and apart from the standard liftpump/PMD issues it's been good and reliable. But this need to be fixed right away. Not a fan of camping on the hard shoulder...
/Jes

Just tell me please, does everyone drive around with 14volts on the meter at all times, except when glowplugs warm up, or the quick dip as the high beams go on?


I do - 14+ volts on the gauge except fro during the glow cycle.

I feared that answer... So I reckon something moves in my truck or expands with heat that allows something to make contact with something but only sometimes. Well it's a start. Like the beginning of the DaVinci code huh?

Just tell me please, does everyone drive around with 14volts on the meter at all times, except when glowplugs warm up, or the quick dip as the high beams go on?/Jes
For the most part, yes.

Ground! grounds! grounds! They're all over your truck and any one of them can cause the problems you're experiencing.

Yeah, but you can't really short ground to ground, but bad ground could affect the max current allowed through any circuit. Hmm intresting... What if the alternator is not properly grounded? That could cause a drop in voltage if it wasn't. It's no cable but just a couple of rusty bolts fitted to a 10 year old piece of metal... Which combined with generally bad cables would solve the puzzle... I like the sound of that.

How's your Heath chip by the way?

Ground! grounds! grounds! They're all over your truck and any one of them can cause the problems you're experiencing.


:exactly:


I'd even go so far as to say it's in the passenger side negative battery terminal. Just a S.W.A.G. here but I forgot to hook up the other end of that cable (to the motor) and I got all kinds of weird problems. Slow cranking and low reading on the volt gauge.

Check it NOW! NOW DAMMIT, NOW! :D

Tim

Jes poor grounding is a common ailment of GMs in general, the main culprit is the wimpy ground on back of the engine block to frame, pass side, it corrodes or breaks & is hidden form view. I add a #4 doulble ring lug batt cable, one end to Alt mount stud, and other end to a cleaned spot on the frame, that has "cured" many a charging/low voltage problem I've seen truck to truck over the years

Hi again!

Thanks for the quick replies! Quite right, cables are not new, only cleaned down to molecular level... But sure, I realize that corrotion can creep deep deep down under the plastic.
It might me an issue involving two separate problems. I just mix em up?
Just tell me please, does everyone drive around with 14volts on the meter at all times, except when glowplugs warm up, or the quick dip as the high beams go on?

I believe I've checked all battery cables and ground wires.
Thanks again for your inputs. I've had the truck for quite some time now and apart from the standard liftpump/PMD issues it's been good and reliable. But this need to be fixed right away. Not a fan of camping on the hard shoulder...
/Jes

Well, my juiced up alternator from the local guy puts my voltmeter right over against the red mark, always has since I owned the truck. If it falls from that mark, i take it to him and he freshens it up.
last time I put an actual voltmeter thing (digital display), I recall it reading just over 15 volts.
No harm to the system, we run 16V batteries and charging systems in the race cars.
The 'nominal 12V' system is just that, I have seen them be just fine up to a little over 18V, beyond that delicate electronics can have problems.
also, you may want to check your guage for accuracy, they were known to be off.
brian.

Ok, I had a similar post on my dads '96. I agree that you should replace all cables, that's two grounds to the engine, one to the body, add a ground between batteries - terminals and two new positive cables and crossover, especially the one to the starter.
I even like the idea of incorporating a battery isolator into the + crossover so that the alternator charges both batteries equally instead of one then the other. This will keep a bad cell in one battery from charging the other battery. a condition that can fry the whole system.

Well, here's my question: do you have a tach? Does it read okay? Just checkin'.

Why you ask, 'cause mine high output super delux bus alternator nose dived last night. Coming home, volt meter at 12 at the stop light with a/c running (common occurance). This time noticed the tach reading at 1000 rpm at the stop light - not so - only supposed to be reading around 5-600 rpm. Long story short, noticed less generating capacity, and having it looked at tommorrow by alternator shop. Will let you know, but I think a diode has gone south on it.

Yeah, as far as I know the tach reads fine. If I release the throttle it will idle around 600 I think and when braking drop another 100 to about 500. Hope that's normal anyways...

I agree. this sounds exactly like a grounding problem. you've got corrosion at one of your connections. take your jumper cables and jump the negative terminal post to your frame. if the truck starts normally with the extra ground connection, clean the ground at the frame/block.

In my burb I have a bad ground on one battery. when both batteries are hooked up my gauge runs at about 14.5 - 15 volts with nothing on but the radio. but when the ground is acting up it hardly runs at 13 volts. I can really notice it on start ups some time it'll pop right off and other times it acts like the glow plugs were not even ran. The engine doesn't turn over very fast either. I'm going to get rid of those damn side post terminals and put on top posts with double 00 cable. Sounds like this may be an option for you're rig too.

Hey guys, since were on the topic:

What is the easiest way to access/remove the starter. I am also having problems with my truck not starting, upon closer inspection the positive lead to the starter is worn through and grounding against the heat shield. The problem is that I can't decide how to get at the darn thing -- from the top (removing turbo and manifold) or from the side (remove inner fender). Which is the worser of the two evils?

Thanks--

I haven't looked closely yet at my starter and associated cables but I bought all I need to do my own cables, and I think I might have the exact same problem as you describe, since pulling on the plus cable to the starter will allow for a normal start as if it gets moved away from whereever it's worn through against frame. The bolts seemed tight to the starter although corrosion might be present. But that would be more consistent and it wouldn't draw amps when driving around.
Can you not change the cables without dropping the starter? That's what I's hoping to do this week.

I have a 94 chevy diesel, have had simular problems with starter, replaced it a few times, the guy at the electric shop told me to put in a new starter regulator (ford style) up top and eliminate using the seloniod on the starter, have'nt done it yet but was told that the chevy starter seloniods not very good...

I meant starter seloniod not regulator....ooopps

The starter is burried between the frame and the block! I tried to drop it from underneath but there is a third bolt, attatched to the block, that I can't even see, let alone get a wrench on. Has anybody removed the the passenger side inner fender? Is it possible to reach that mystery bolt and the solenoid terminals with it removed or is the starter/solenoid still to "tucked in" to access?

I have removed my starter, you had to remove the little brace rod there, ( having a little memory block) remove the bolts from the inspection cover, bottom back of engine, kind of covers the starter a little, I did'nt have to pull that pan out If I remember right, just took it loose to get it out of the way a little, I used ratchet with swivel socket and extensions to get that hard to reach bolt that is out of sight, and small hand and little wrench to get to seloniod wires.. not too easy,
and the last time I had the shop do it, starter only lasted a couple of months, took them no time at all to have it out.. But they did recommend puttine a ford style starter selonoid in and bypass the regular starter selonoid.. Hope this help a little..

Back to the voltage problem. I recently noticed slowly decreasing voltages as I drove and also sudden changes in voltage. Definitely a cable problem.. Seems to be caused by a stripped stud connection on the passenger side negative.

my truck starter spun fast enuf and then one day it 2 slowed down as though the battery had run down. i checked each for voltage and found a suspect battery. canadian tire sold me a brand new one and i asked them to recharge it before i took it. they did and it failed their battery test. so did #2 and #3 battery. the 4th was fine. maybe you got a defective battery. as canadian tire told me they had a problem with some of their batts. but were told sellem anyway as they are warrantied. take the battery in for a free test, just my 2 cents.

Update:
Removed all battery cables, threw them away and did my own. Pulled extra cables engine to frame and one minus straight to the alternator bolt. Replaced braided wire engine to firewall. Also dropped the starter in the process cleaning it thoroughly. (This starter by the way is no match to drop. The bolt at the front of the vehicle holding the bracket proved most tricky. It is clearly visible though and a wrench with a 4'' extension till loosen the bolt. Then I used just the socket with an allen wrench jammed in the little hole of the side of the socket to get leverage and unscrew the bolt by hand. No need to remove any other stuff like fenders etc.)
Anyways the original cables were corroded and with my new setup I get a descent turning speed, but nowhere near as fast as I remembered it to be in the past.
I'm going to try using a battery booster starter help kit to give that starter a good extra 400 amps. Just to see if the engine really does turn slowly due internal wear or something.
BUT, the mysterious voltage drop on the meter is still there. Typically it drops when slowing the vehicle down or driving downhill. It can jump up and down from 9 to 14. I haven't excluded the possibility that a battery is bad. Both measure 12.82 volts and are 18 months old only. This business with breaking or tilting the vehicle does draw my thought to moving liquid.... not found in many places...
I suppose I could start the truck, disconnect the batteries and run on alternator alone to see what happens.
What´s mysterious is that the batts come up with 14 when charging regardless of reading on the dash, so maybe the dash instrument is to blame?
Thanks for all inputs so far!