A/C causes ML430 to misfire/stall - PeachParts Mercedes-Benz Forum

mars23 · #1 07-14-2007, 02:00 AM

I took my ML430 to a MB tech b/c my car will misfire or cut off (twice) if I turn on the A/C. Also, the check engine light will come on. When I turn off the A/C the car runs fine. The tech said the codes read MAF. He checked the car out for 2 days and said it was not the MAF. He said my AUX fan fuse was missing, which he replaced. But he said the A/C- AUX fans were drawing too much power. I have an Interstate battery 750. He said the negative batttery cable wire was corroded and the battery was leaking. He checked all other wires, but can't seem to find the exact problem. He suggested I get a new MB battery 800 or 900 through roadside asst. and replace the negative wires. Has anyone had this problem? Would a bad battery stall the car upon turning on A/C? Any other suggestions.

Thanks in advance.

mbdoc · #2 07-16-2007, 08:25 AM

There is a "factory" mod for the aux fan wiring. Heavier wiring and a heavier Amp fuse.

Of course replace the negative cable if corroded.

mars23 · #3 07-18-2007, 04:35 PM

Thanks for the info. I will ask tech to replace wiring first. Upon starting the car today it seemed like it didn't want to start. Then as I drove it, it seemed like it wanted to cut off at a light. 1/2 mile later, it stalled as I turned into a driveway. But then it started right up. I went home and parked it. I call Roadside, they said they don't think it's the battery. But I'm going to get it replaced anyway.

mbdoc · #4 07-19-2007, 08:06 AM

Try search for flywheel crank sensor failure on M112/113 engines.

They will cause that type of problem.