Skip the auto shop - Our mechanics make house calls

Q: I Reversed battery cables on My 1992 Mercedes SL500. Now it turns over but won't start

asked by on

I hooked up battery cables backwards and blew something car turns over but won't start replaced OVP fuse 20amps still won't start

My car has 10000 miles.
My car has an automatic transmission.

When the battery cables are reversed, It only takes an instant to do a lot of damage. The Alternator and the ignition modules are probably toast, And any or all of the ECU’s are probably damaged. The good news, if you can imagine any in this situation, is that this car was built before Mercedes started "marrying" control modules. That means you can do substitutions with a salvage car.if you can find one. Later Mercedes modules were matched to each other with a code so that chop shops could not get away with selling used modules but your car was built before this happened. Sorting this car out will take a technician skilled in electronics equipped with a lab scope. If you want to get some professional help with this, you can contact Your Mechanic to have a technician come out to your home or office to check out your car and give you an evaluation.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. I Reversed battery cables on My 1992 Mercedes SL500. Now it turns over but won't start

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Every couple of months nothing happens when I turn the key on my 2004 Xterra but latter it works also seeing intermittent tempertu

This may be difficult to diagnose without additional detail, however what you are describing sounds like potentially a faulty starter relay. If you hear a clicking sound and all power shows up on the dash, this is common when the...

Q: Ran out of gas ('92 Mercedes 500SL) now the car will not start after adding gas

If the car is on level ground, the 2.5 gallons should be enough to cover the fuel pickup. If the car is on a hill, or leaning to one side or the other, it might help to add more gas....

Q: blow by around pcv and around oil breather cap.

Hi there. Engine blow-by is the result of combustion gasses getting past the piston and/or piston compression rings, this builds crankcase pressure. The PCV (positive crankcase ventilation) valve system is designed to remove the pressure and recirculate the gasses back...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...