Electrical Problems on 2000 chassis

[Ramzfan]

I own a 2000 Fleetwood Discovery on a Freightliner Chassis. I am having problems with the dash electrical which creates the following:
1) The engine seems to cut off at speeds around 55MPH and above. It only does it for a split second but it creates a jerking feeling in the coach. It creates havoc with the cruise control.
2) The Air guages fluctuate continually, going from full air to zero air. The low air light goes on and off.
3) The alternator (charging) guage does not seem to come up to full charging when the engine is first started. After I give it some throttle, it will finally come up to where it's supposed to be.
Anyone got any suggestions? I'm planning on cleaning all of the battery connections and the ground connections first to see if that helps.

[geodays1]

I too experienced similar problem at higher speed under load usually on hill, After experiencing a oil pressure sensor failure on my Cat 3126B the problem has gone away!! I have a Newmar 2001! Dutch Star. Also a freightliner.
The Air gauge problem is similar to problem I had with the VDO computer in engine compartment that controls all dash gauges, Computer has solder track craking and was replaced in Warranty! I believe it could be affecting your charging gauge on dash!! Hopes this helps

[J Walker]

My 2000 Freightliner XCS chassis has a similar operation for the charging after start up. It takes a few seconds for the voltage to register and I consider it normal and not a problem. I had an air pressure fluctuation problem and it was solved by Freightliner, Gaffney by replacing the VDU computer in the engine compartment. There is a procedure to re-solder the circuit board which accomplishes the same purpose. I have a detailed procedure if you are interested. I have not experienced the engine cut out at 55 MPH. That could be tough to troubleshoot unless it is repeatable.

[Ramzfan]

Quote:

Originally Posted by J Walker My 2000 Freightliner XCS chassis has a similar operation for the charging after start up. It takes a few seconds for the voltage to register and I consider it normal and not a problem. I had an air pressure fluctuation problem and it was solved by Freightliner, Gaffney by replacing the VDU computer in the engine compartment. There is a procedure to re-solder the circuit board which accomplishes the same purpose. I have a detailed procedure if you are interested. I have not experienced the engine cut out at 55 MPH. That could be tough to troubleshoot unless it is repeatable.

That's very interesting...did they fix it while it was still under warranty or was it past warranty? Mine, being a 2000, is eleven years old. I wonder if they would still honor the warranty? As far as the 55 MPH cut out goes, I believe that is a part of some electrical circuit board problem also, unless it's in the wiring harness. Thanks for your help.

[J Walker]

Quote:

Originally Posted by Ramzfan That's very interesting...did they fix it while it was still under warranty or was it past warranty? Mine, being a 2000, is eleven years old. I wonder if they would still honor the warranty? As far as the 55 MPH cut out goes, I believe that is a part of some electrical circuit board problem also, unless it's in the wiring harness. Thanks for your help.

I was at about three years when I had Freightliner replace the VDU. I tried to use my extended warranty, not from Freightliner, and they refused. I didn't think to ask if I had any Freightliner warranty left and now I wonder. The problem definitely began under warranty and then slowly progressed to get worse. I feel sure that 11 years is out of warranty, but it pays to ask. This was a common problem for VDUs until they got the part problem fixed, so Freightliner might share the cost with you.

[geodays1]

Since, I did experience the engine cutout or what I called intermittent miss on hills under load, I believe its related to the Oil pressure sensor that controls the fuel injection! The sensor controls voltage to the computer, failure of this sensor causes total defuiling of the engine. Computer check by caterpillar showed multiple spikes in Voltage of the sensor over a long period of time! This info is stored in the computer memory. Its worth the money to get yours Flashed at Cat and avoid being broke down on the highway anytime!. Just saying my experience.

[Dacotah]

RAMZFAN, which engine do you have? If it is an ISB Cummins, the sensor that detects engine rpm can be faulty. It will show up on a fault code if you have a technician hook up the computer to your motor. The other area which can affect the charge readings is the 5 fuses and holders in the battery compartment on the left side by the starting batteries. These automotive style fuses can get corroded and not pass voltage properly to the engine computer. The best fix if you find them corroded is to replace the holders with marine sealed ones that will not allow moisture into them. Hope this helps. DACOTAH

[Airtool]

To All, the ISB series Cummings ECM connections right at the engine can get corroded and cause some interesting problems.
My main issue was a intermittent or surging cruse control. I finely found the problem by stopping when the cruse would not engage or would surge when active by opening the doghouse and wiggling connections. Remember its hot in there and when you are on top of the engine place a throw rug on the valve cover to keep from burning your knees. AH yes !! find the location of your ECM when the unit is cool !!! Everything worked fine wen cold by the way.
The problem would go away for a time. After three times I removed the connectors and VERY carefully cleaned the pins. Now you want to do this when the engine is cool.
The connctors are well protected and sealed for the most part and screwed together.
This is a job for someone who has spent some time working around engines.

Dick,Bounder Diesel.

[RJay]

Dick,
Thanks for the heads up!