w124 coupe 2.3 1986

[02galant10]

hi all
hope somebody can help me
my car starts fine but when a load is put on it
(lights / heater / stereo) ect the car cuts out and all electrical power is lost..the car will restart after a short time. battery shows 12.4 volts with engine running at 2000 revs. i suspect the alternator, but charge light is not showing on the dash.?.

 

[grober]

The alternator output at 12.4 volts is too low---- may simply need a new brush+regulator pack rather than an entire alternator- any decent vehicle electrician should be able to check for you . Other possibility is a faulty OVP relay or its fuses.

 

[02galant10]

Hi thanks for getting back to me, i will get the car to my local electrician, to be checked out..
Thanks

 

[02galant10]

230ce electrical problems

hi
i have had the alternator checked but no fault was found, now looking for this ova relay, can you help with the location of this part?

 

[grober]

The OVP [overvoltage protection relay] is found behind the battery. There's a flexible plastic shield you have to remove when you should see some relays and maybe the engine and ABS ECUs. The OVP relay should have one or two fuses mounted on the top of it- check and clean the contacts of these first. The next thing is to remove the relay can to expose the innards. Get someone who familiar with a soldering iron [ maybe yourself?] to go over all the soldered joints on the small PCB as they're known to develop cracks over the years-- its that or replace the relay if that's the source of your fault.

 

[02galant10]

with the alternator overhauled (belt and braces ) and the ovp relay found to be relatively new and in good shape, the car still has the same fault, with the engine running as normal as soon as a load is put on the system, the car cuts out and all electrics are dead..just like the battery terminal has been removed..

 

[grober]

Other possibility is a faulty/broken/corroded engine earth strap. Any engine movement might break the connection? If its a braided strap its easily checked visually--- if its a sheathed cable could be broken inside the insulation.
usually located beside the bell housing.

 

[02galant10]

hi thanks Graeme
i could put a jump lead from the neg pole on the battery to the engine block, that should rule out poor engine earthing..job for tomorrow..

 

[optimusprime]

As above check out the fuses give them a turn in the fuse box . And earth leads need removing cleaning and re fit with grease on them But first ,,if you have your radio code , remove battery leads check them both out + and - and clean them up with emery paper a little grease and bolt them back on in the righ place .Then if it is still playing up i would look to the ignition switch .Do you have a charging light on the dash showing at any time before you start it if not then it might not wo0rk .And if the bulb is out it wont charge the battery up .

 

[optimusprime]

Do all the light go off on the dash? I would say a bad earth ,check engine to chassis and bell housing to engine earth cables .A main shut down of power, is earth ,or lack of it

 

[02galant10]

hi thanks for your input,
both battery leads have been off and cleaned before being refitted, i inspected the fuse box
finding that all looked good.. replaced all fuses, some fuses did look a little corroded, just run the car 30 mile round trip, and it never missed a beat...(fingers crossed)