Engine Dies When Electrical Load Increases

Forum for both AC and DC electrical components. From engine alternator to dashboard, inverter to batteries, and everything electrical in-between.
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LeeTN
Posts: 18
Joined: Sun Oct 27, 2019 5:44 pm
Location: Eastern Georgia, USA

Engine Dies When Electrical Load Increases

Post by LeeTN »

My coach's engine dies whenever there is a significant electrical load increase. This happens when I use the levelers, even with the engine turning at 1500+ rpms. The windshield wipers (when on high) will also kill the engine. I presume there is an electric solenoid in the fuel line that is a normally closed unit and this shuts off the fuel when the current drops (from a high electrical load somewhere else). If I use the boost switch (to add the house batteries to chassis batteries), it helps; but the engine will still die sometimes. Running the generator also helps, but yesterday it died even with generator running and boost switch.

This all seemed to begin after I had a chassis battery die and I rewired all of the batteries. The previous owner was a big proponent of jury-rigging stuff on the bus... and he had run two jumper wires (4/0) from the house batteries over to the chassis batteries. I figured he'd done that so the solar panels would keep the chassis batteries charged. Since the boost switch worked fine, I removed them when I rewired. I also replaced one chassis battery... I know you're supposed to replace them as a set, but the other had tested good on electrolyte and would hold charge well. After driving it yesterday for about an hour (and having the engine die regularly) I checked the batteries (as sets) with a multimeter... chassis were at 13.27v and house at 13.7v. During all this, the engine turns over well and would start fine, though the starter did slow a bit after being used about a half dozen times while backing up the driveway. At idle, the engine would die if the steering hit the locks... I think this causes the electric backup hydraulic pump to activate.

Also during rewiring the batteries, I noticed that the leveler pump/solenoid were wired to the chassis batteries. I moved this over to the house batteries. I suspect I'll have to replace the other chassis battery, but it seems to me the problem has other causes.

If anyone has insights, please let me know... Thanks!

Lee
'93 Continental 40'
300 Cummins -- Allison 6spd
Lee
1993 Continental 40'
Oshkosh Chassis -- Cummins 300 -- Allison 6sp
Robert K
Posts: 105
Joined: Mon Oct 28, 2019 2:27 am

Re: Engine Dies When Electrical Load Increases

Post by Robert K »

On my 96 the leveler pump is wired to chassis batteries. No ideas on engine quitting but if I see mechanic friend I will ask him.
Bob
96 Serengeti 37'
3126 Cat
6 speed Allison
2011 jeep wrangler towd
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