Author Topic: Slow Crank  (Read 4391 times)

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Offline Vorlon

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Re: Slow Crank
« Reply #25 on: April 08, 2018, 05:02:17 PM »
Hi Ziggy,

I have wiring digram, but all cables into the harness look the same! So I will have to trace to be sure.

I plan to call gulfstream tomorrow and see if I can get a floor plan that perhaps shows if and where any hatches are.

Will post when I have more news.


Cheers


Dave


Offline ziggyh

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Re: Slow Crank
« Reply #26 on: April 10, 2018, 03:31:54 PM »
Dave, have you thought of tracing the wire and once identified attaching a strong rope to one end and pulling the cable out and then use the rope to pull a new cable in. Once the old cable is out exanime it for any other signs of damage.  Hopefully they aren't secured somewhere along their path.

Wires usually start to show sighs of heat at or near the point of a poor connection, corrosion or damaged area where some strands are damaged. As current passes through a poor connection or resistance it causes a drop in voltage which is turned into heat.

The only time a wire may show signs of heat damage that is not at a point of resistance is if the wire is too small a guage for the current required for the load or as a result of a dead short.
ZiggyH

2007 Revolution LE
C9

Offline Vorlon

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Re: Slow Crank
« Reply #27 on: April 11, 2018, 04:57:59 AM »
Hi Ziggy,

Thanks for the ideas. Unfortunately this harness is strapped to the side of the engine with metal straps. Also I cannot get to the block to undo the destination attachment.

I contacted gulfstream themselves (they have not manufactured motor homes for some 10 or so years now). there was no one left who had ever worked on these, but the advice I received from the V.P. there was as follows:-

"The entry hatch originally designed into the bedroom engine access port was very limited. In some cases air cleaners and turbo hoses would need to be dismantled. In extreme access situations, the engine is designed to be removed from the rear. Not saying that you need to remove the engine to perform your service work, but it may require removal of the radiator and or accompanying shrouds around the radiator opening In order to access the points that you are attempting to access."

This has at least resolved the entire dismantling of the bedroom and carpeting as it appears that there is only the one access hatch. It looks like my only way forward is the removal of radiator and shrouds.

No wonder it is so expensive to have any work done on these units!

Thanks again for everyone's help and suggestions. I will report back if and when I get this done.

Cheers


Dave





Offline Vorlon

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Re: Slow Crank
« Reply #28 on: July 30, 2018, 06:39:14 AM »
Update as the saga continues!

We have nice warm weather now so I started working on my problem again. Firstly I was unable to access the engine block ground connector so I purchased #1 cable and directly connected new connections from starter neg to the block and chassis. This did not help. Secondly I went to a local auto repair shop and borrowed a battery load tester to double check the "new" batteries and found that the supposed 1000 CCA's were only 550 CCA's each!! So called the battery store and complained bitterly. They exchanged them and I load tested the new ones which showed just on 1000 CCA's each

Still slow crank.  I then had a thought and asked my wife to crank it while I was underneath observing the starter. The starter became extremely hot within a couple of seconds while trying to crank. I now wonder if possibly I have a seized accessory maybe the alternator?

Any thoughts???


Cheers


Dave



 

Offline David.e.atherton

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Re: Slow Crank
« Reply #29 on: July 30, 2018, 06:56:18 AM »
Vorlon, you indicated the starter got very hot just started cranking. Where did you buy the
starter. Is it a Caterpillar reman or local parts store rebuild, because now you are chasing the problem back to the starter ( new battery’s, new grounds cables new positive cables and
Batteries new check out new ). Do you have a hyd pump driving a hydraulic fan motor or
on hydraulic pump itself there is a splitter valve that is sticking and turning engine into dead
head hydraulic fluid that cannot shift hydraulic valve spool or partly move valve spool, this
would be about the only area that could cause drag on your engine if starter is good.
Ask Dave Dave Atherton Retired Cat Mechanic

Offline Vorlon

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Re: Slow Crank
« Reply #30 on: July 30, 2018, 08:11:04 AM »
Hi Dave,

Thanks for your reply.

The starter motor that I replaced was a Nippon Denso which I am assuming was the original starter motor. I replaced it with an identical model, brand new Nippon Denso.

The engine is a Cat 3126. Quite frankly I have no idea if it uses a hydraulic pump, fan motor or splitter. I will call freightliner and ask. The reason I wondered if the cause could be say a bad bearing on the alternator is because one of the leads from the starter to the engine was severely overheated. I posted a picture earlier in this thread.

It is pretty much impossible to examine or access the engine area, so I was unable to trace where the burnt connection went to.

Cheers


Dave

Offline David.e.atherton

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Re: Slow Crank
« Reply #31 on: July 30, 2018, 08:30:46 AM »
Vorlon, my suggestion at this point  to go to a Caterpillar Dealer and  get a Caterpillar
Reman. Starter and is for correct engine S/N. I find it is best to put on a proven OEM
part. I understand the trend for people to save money but some times like kind does
not work correct. I find giving technical help sometimes will not work because not knowing
the unknown type of replacement parts, aftermarket or OEM factory parts.and dealing
with tight spec’s that some replacement cannot meet. Ask Dave. Dave Atherton Retired
Cat Mechanic

Offline David.e.atherton

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Re: Slow Crank
« Reply #32 on: July 30, 2018, 01:47:54 PM »
Vorlon, back agin I need your Cat 3126 engine s/n number. What I have located,
Caterpillar technical Service bulletin on slow cranking with some earlier Cat 3126
engines. What I plan on doing is pulling up your engine build date and arrangements
number assigned to your engine serial number, than I can breakout the correct starter
number that your engine was shipped with. Ask Dave,  Dave Atherton Retired Cat Mechanic
.

Offline Vorlon

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Re: Slow Crank
« Reply #33 on: August 02, 2018, 05:53:31 AM »
Hi Dave,

Thanks.

OK on looking at the top of the engine (tough due to tiny access point) there appear to be 2 numbers. 2 (or maybe Z) CPXH0422HBX or HEP03945. The engine is labeled 2002 although the motor home is a 2003.

Update, I spoke with freightliner who advised that Nippon Denso starter motors were in fact used on many of their models and that the one I removed was probably the original unit. I removed the new starter and took it to an auto electrician. It tested perfectly. So I am left with something else perhaps a seized accessory like an alternator. If so I would need to release the accessory belt/s to test. Again a problem in terms of access. Dave, the engine is at the rear so I noticed there is a large hydraulic reservoir so maybe there is some hydraulic problem.

Thanks again for your help.

Cheers


Dave

Offline David.e.atherton

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Re: Slow Crank
« Reply #34 on: August 02, 2018, 07:37:34 AM »
Vorlon, do not have muck faith with camp Freightliner, reason many problems with many
Motorhome with Cat or Cummins engine they had there own ways to addressed problems
that did not corform with any kind of standard builder suggested. Removing the Secondary
1R-0751 fuel filter off th engine for 4 or more years and just had a water/ fuel in its place is
a prime example of where I’m going with this. Will look up the correct starter tonight and will
work away from that point.  Ask Dave  Dave Atherton Retired Cat Mechanic

Offline Vorlon

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Re: Slow Crank
« Reply #35 on: August 02, 2018, 07:39:54 AM »
Thanks Dave.

Cheers


Dave


Offline David.e.atherton

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Re: Slow Crank
« Reply #36 on: August 02, 2018, 11:33:43 PM »
Vorlon, update on what I found. Serial number prefix CPX listed as a vibratory compactor
model CP-548, next Serial number HEP 03945 is a good number which engine comes
back Cat 3126 E, 330hp. Build date 2002 - 07- 22, test date 2002 - 07 - 23,  shipped date
2002 - 04 - 23.  Arrangement Number 225 - 2098.  Heavy duty 12 volt starter, Caterpillar
Number 175-7332  12 volt. Note: starting motors that operate to slowly can have an overload
because of to much friction in the engine being started.  Slow operation of starting motor
can also be caused by a short circuit, loose connection and or dirt in starting motor in starter.
Last question are you sure your starter is not 24 volt because there is a 24 volt model also.
Ask Dave  Dave Atherton Retired Cat Mechanic

Offline Vorlon

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Re: Slow Crank
« Reply #37 on: August 03, 2018, 05:59:30 AM »
Hi Dave,

Thanks for the info.

I am certain on the starter being 12 volts, both old and new are marked 12v. I have also sent the old motor in for testing.

I suspect that the starter motor is not the problem because both were doing the exact same thing. 

In retrospect it may assist if I detail the history of this problem. It started the beginning of the winter before last. We had just returned for a short trip to a local (25k distance) campground. I parked the unit in my driveway (where it has remained ever since), extended the leveling jacks and winterised it. I plugged into shore power and turned the battery switches off (Coach battery inside the unit and starting batteries in their compartment). It sat for about 5.5 months before I came to start  it. I do not recall the temperature when I came to start it at the end of winter, but I do recall NOT plugging in the block heater. The cranking started off and actually seemed normal maybe a little slow at first but nothing like now. After about 10-15 seconds it seemed as if the batteries were running down and shortly after it would not crank. I placed the batteries on a 40 amp charge rate and left them to charge for about 1.5 hours. When I came to try and start it the ignition key did nothing. Using my multimeter I determined that the battery on/off switch in the compartment had ceased to function and remained permanently in the off position. I removed the switch out of the circuit simply by bypassing it. From that moment on I have had this slow crank.

I am wondering if this background sheds any light on the problem, perhaps I did something wrong??

I really appreciate all the help you and everyone else has given me.


Cheers


Dave

Offline David.e.atherton

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Re: Slow Crank
« Reply #38 on: August 03, 2018, 07:33:15 AM »
Vorlon, let’s try one more thing. The good jumper cables and connect direct to starter.
Connect ground to starter than battery than take postive cable and connect direct to
Starter post below the solenoid. Than take positive cable end on jumper cable and touch
positive battery post on battery ( this is your starter button ) . And last put you hand on starter and tell me if it getting hot. Ask Dave, Dave Atherton Retired Cat Mechanic

Offline Vorlon

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Re: Slow Crank
« Reply #39 on: August 05, 2018, 05:51:46 AM »
Hi Dave,

I have previously added parallel cables to the starter directly from the batteries with no discernible difference. I will either today or tomorrow (its a long weekend here in Ontario and my wife and I have 5 rugrat grandkids between years and 3 months to babysit!) try the cables direct to the starter and use my powerprobe to activate the solenoid, this way I can check the temperature of the starter.

Cheers


Dave


Offline David.e.atherton

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Re: Slow Crank
« Reply #40 on: August 05, 2018, 08:00:38 AM »
Vorlon, thank you for getting back with me, again things point to the starter. One thing
The little wire going to the starter solenoid check that again and run a new jumper wire
with the by-pass jumper still connected up. Yes you have. Slow crank on your engine
but not convince we have a good starter at present. Once you know for sure you have
the starter is ok and cannot do any more. The problem is deeper into engine and at this
It requires Technician that has been schooled with the Heui engine. Weighting the cost
of starter replacement and weighting cost to bring it into service shop is your next move.
I’m not pushing buying parts, but not convinced until you have a Caterpillar starter put
on your engine to attempt to go deeper into the engine. I have been down this road many
times and lots of expense only to return to install correct starter and problem solved.
AsK Dave, Dave Atherton Retired Cat Mechanic