500E cuts power & dash lights on over hard bumps

[henrycg]

Hey guys,

Wondering if y'all can shed some wisdoms. When I am either accelerating or cruising and I hit a pot hole or a bump of noticeable size of which there are many on British country roads, the car acts as if the ignition was turned off and on again for a fraction of a second. All the dash lights come on and then go off and it goes back to normal.

If I hit said bump while flooring it, then for a fraction of a second I loose all power as the car seems to be "off" for that fraction of a second, hence why all the dash lights light up as if the key had just been turned.

It really is only for a fraction of a second tho so if you're not accelerating you don't notice it. But will certainly get annoying if I'm doing the North Coast 500 - which I highly, highly recommend btw.

P.S. If you'd be interested in doing the Scottish Highlands in a serious motor, I run a tour company, and this is a new avenue which my business partner and I are thinking about atm. Definitely get in touch if you fancy coming to Scotland and driving the NC500 in a 500E, SL500 or others

Anyway about the problem any ideas? Thanks in advance

 

[maw1124]

Are your battery connections tight? That's about all I can think of, actually.

maw

 

[sheward]

Have both wiring harnesses been replaced? You might start by cleaning all the ground spots on the car. There are several. I've seen a diagram here on the forum somewhere that shows all locations. A major one on the passenger side strut mount. Another under the center console. Check that all modules are seated properly. Check the positive cable bus, between the can box and firewall. You might also inspect the area under the passenger foot board. Here in the states many cars had aftermarket alarm systems installed there. Many times badly.

 

[nocfn]

Check wiring to alternator as well.

 

[henrycg]

Appreciate these replies thanks guys

 

[nocfn]

all about the base (module). That CAN box may hold the key as well. Not a bad idea to open her up check each fuse and reseat along with the removal and seating of the modules themselves. Whack - A - Mole (industry term) with rubber mallet to ensure they are seated

 

[gerryvz]

@maw1124 is 100% correct.

Classic sign of the positive battery terminal (both the main and the smaller CAN power lead) not being secured to the positive terminal of the battery. Remove, clean, and re-install securely.

Same exact thing happened to me some years ago.

 

[nocfn]

damn terminals...er millennials... yuck yuck

 

[PJmak]

Potentially loose ground wire on the chassis?