Can driving car without OVP relay cause damage?

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snakehips916

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Hi,

Since aquiring the car 2 years ago it has always had a cold start problem. I have managed to live with it as my motorcycle is my main form of transport.

However, as it is worse in winter I decided to do some investigation. I removed the OVP relay which I believe is the source of many problems (Esp. as my ABS light is also on - it came on about six months ago). I took the OVP relay to Merc who said a new one is £70. I thought that was a bit sharp considering it might not be the problem, so took it home and was going to try to source one from elsewhere.

In the mean time, might motorcycle wouldn't start this morning so I hopped in the 190 forgetting that I had removed the OVP relay. It started immediately! It has never done that. I then drove it to work. Have I possibly caused and damage and does this prove it was the OVP relay at fault?
 

mikestrivens

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The OVP is there for good reason. I would not drive the car without, or you could do some expensive damage. I had a similar problem with the OVP on my 280TE. I did end up buying another but took the old one apart to find several dry joints. I resoldered these and it worked fine thereafter.
 
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snakehips916

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Thanks Mike. I will explore this evening.....if the old girl makes it home:D
 

television

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You can drive the car without it,, the circuits that use it like ABS and ASR will not function, but no harm can be done.

As Mike they do solder up often, but can fail with component failure
 
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snakehips916

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How do I dismantle the OVP?

Thanks guys:D If I was to dismantle the OVP which end do I start from?
 

wireman

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Slit the lower corners of the can so that the edges can splay apart and pull off the cover, this avoids distorting the case. Re seal it with RTV on assembly.

Look very carefuly at each solder joint on the circuit board you will like as not find microscopic cracking of the solder where it it stuck to the through hole pins of the components, look especialy at the heavier parts like the skeleton relays coil connections.
Use a rosin flux and reheat each joint till the solder flows nicely, try to avoid adding loads of extra solder since the extra mass may just make it even less reliable. If you are not familiar with electronic contruction techniques get some assitance from one who is. Cleanliness and being devoid of oils/grease are the key points to good soldering.
My OVP has been repaired for the last 40,000 miles and it aint given a beat of trouble since.


The ovp powers abs stuff and on some models the tickover control system. Without it these systems dont function due to no 12v power, just like they dont function with a dud OVP, so I cannot see (with my electronic engineers hat on) what risk of damage there can be if you run without it.
 


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