Alternator replacement / stalling / Code 35s

[markrinker]

Truck #2 has always started within 2 seconds cranking after full glow cycle. Today, it started cranking 15-20 seconds before starting, and tonight, required 3 glow cycles before starting. Have had no stalling, no rough running or other symptoms once running. Just the long cranking...

Only other clue is the volt meter has been running lower than normal, but with hot spell, I attributed it to running A/C and fan on high most of the time for the last week. One morning, the truck turned over slowly like the batteries (both new last month) were not recharging properly. Short on time, I threw the battery charger on for a few minutes, and things had been fine since.

Could a bad ground be causing the lift pump to not operate?

[ 07-24-2004, 09:27 AM: Message edited by: Mark Rinker ]

[CareyWeber]

Originally posted by Mark Rinker:
Truck #2 has always started within 2 seconds cranking after full glow cycle. Today, it started cranking 15-20 seconds before starting, and tonight, required 3 glow cycles before starting. Have had no stalling, no rough running or other symptoms once running. Just the long cranking...

Only other clue is the volt meter has been running lower than normal, but with hot spell, I attributed it to running A/C and fan on high most of the time for the last week. One morning, the truck turned over slowly like the batteries (both new last month) were not recharging properly. Short on time, I threw the battery charger on for a few minutes, and things had been fine since.

Could a bad ground be causing the lift pump to not operate? Mark,

Is the cranking speed normal or slow?

If slow I'd start by cleaning the battery cables (don't forget the end at the starter), or even better replace them with good ones made from welding cable (I use 1 ga welding cable).

Carey

[markrinker]

It might be slightly slower than normal, but not much. In fact, I was suprised to get 3 glow cycles and 15-20 seconds of crank with no problems - only due to the new batteries.

[rjschoolcraft]

Have you tested your alternator?

[markrinker]

Thats next. As long as it starts this morning, I'll let it run all day during short stops while delivering steel. Hopefully I can get the alternator off and tested Saturday.

[moondoggie]

Good Day!

If you've got a voltmeter, you can test your alternator yourself. Start the truck & measure the voltage - you'll probably see 14.5 or so. Turn your HVAC blower on high & your rear window defroster (if you have one) or some other large load - most GM's will still have 14.5V at idle. If if drops some, but raising the rpm to 700 - 800 brings the voltage up, you can be at least 95% confident your alternator's OK.

Blessings!

Brian Johnson, #5044

[Kennedy]

Was the charger on when you started it the one time? Likely raised hell with the glow plugs or relay.

Just like the no ether warning, we shouldn't run boosters when attempting to start.

[Kennedy]

Building on the new batteries, now low charging thing:

When batteries get weak and are run weak for a while, the alternator is stressed excessively. By the time the weak battery(s) are replaced, the damage has often been done.

This is why we often need batteries and alternator within short time period of one another...

[markrinker]

JK - not sure if I started it with charger on, but probably did. 6AMP variety. Glow plug light seems to cycle 'normally', even getting the short afterglow - once the engine starts.

650 miles today - half with a 9500 lb. load and the plot thickens on #2...

1) The truck started okay in the morning, and ran fine under load. Since it was cool out, no A/C and the dash voltmeter read about 13V.

2) Got pulled over by the DOT (another story altogether.)

3) Went to get back in my truck, which I left running, and it was dead. I mean stone-cold-no-dash-lights-no-crank-dead!!!

4) Started looking at battery connections with great ernest by the side of the road. (Had only been inspecting grounds before.) Found a REALLY bad connection on the passenger side postive side, a 10-gauge wire that splits off from the starter cable. Obviously had been tapped in the past, and then re-connected with a cheap connector that was melted and wires green with corrosion.

5) Got a ride with the DOT cop into town. Bought 10gauge connectors, 10 guage wire, and crimping pliers, rode back and in 5 minutes had fixed bad connection.

6) Truck comes back to life, fires up quickly. All systems normal, suprised to see same voltage reading on dash of 12-13 volts. Still, I am convinced that I have solved 'root cause'.

7) 350 miles later, in bumper to bumper Minneapolis traffic, A/C on, truck stalls. Full power to dash and starter remains. Restarts, then stalls again seconds later. Restarts and gets me 60 miles home with no issues. What a trying day!

As soon as I eat dinner, I'll go pull codes, if any. No SES light. Was planning to leave at noon tomorrow for a 300 mile trip to my hometown County Fair for a truck pull tomorrow night.

I do have a good warranty pump (from original engine that broke crank) with an almost new FSD attached to it in my garage, but no extenstion harness or heat sink....

What should I do?

[ 07-23-2004, 05:13 PM: Message edited by: Mark Rinker ]

[Barry Nave]

A really hot Eng. bay Huh :D
Sounds like the FSD is starting to tell you I'm going out and I'm tired of the heat :D
Any chance you can get a big Alum plate to mount the spare FSD on. Temp. install only unless it is machine flat and remote mount with Ext. harness in a cool area.
I still like my FSD cooler as is on intake ;)
Have had the fsd screws issue yet also have more then 55K on it where it is. smile.gif

[markrinker]

Alternator is getting replaced this morning, tested out weak. Pulled codes and got a '35'.

While waiting for parts to arrive, went to run errands and truck stalled, easily restarted. Power to dash never was interrupted. Truck and ambient temps are cool - probably in the high 50s.

Could a failing alternator cause the stalling, or could it take out an FSD? Seems like I am battling at least two problems here...

[rjschoolcraft]

I think the FSD is failing (as others have said) and that it is unrelated to the other problems you've mentioned. I mounted a new FSD on a Beta cooler from Kennedy in front of the left battery about 24,000 miles ago after similar symptoms (stalling).

[markrinker]

New 105amp alternator in place, all battery connections cleaned and tightened. Volt meter now reads 14 regardless of how many accessories are running. Hard starting has disappeared, it was cranking slower than normal.

Cleared Code 35s and will see if they re-appear. Wondering how long it has been set - could Heath 2.0 chip set this code and I never knew it? (No SES light.)

Tossing spare IP/FSD behind the seat and heading out for the truck pull 275 miles away...TBC

[Barry Nave]

Low voltage will cause many related troubles.
FSD could act as though it is going bad yet low volts could have also made the FSD weak.
I would use the pmd as a test and take a spare.

[markrinker]

Stalled out 3 times during the trip, luckily not during the truck pulls. Other than that, running fine and starting normally.

Ordering FSD cooler and extension harness Monday.