testing a OVP - PeachParts Mercedes-Benz Forum

Adler · #1 03-02-2012, 12:21 PM

Any site or experts on How to test a erratic OVP unit , just re-soldered the joints the relay clicks but no output voltage at pins 87.
Thanks

Adler · #2 03-04-2012, 09:55 AM

Thanks to Arthur Dalton, his posted mail on testing a OVP
dated 08-13-2009

Take the relay and hold it bottoms-up so you are looking at the pins, with the bottom row being the row that includes the one small pin. Put it in a vice or some holder.

So , the number for each row of pins as they face you , will be :

Bottom row ..L to R
1,3,5
Middle row L to R
2,4,6
Top row
7,8,9 ..L to R

Bring 12 v + to pin 1
Bring 12 v - to pin 5
Alligator clips work well here.

Now , take the test lamp and hook one lead to the battery - [ this lead stays there for all test]
Test pin 1 and 9 with other lamp lead ..lamp should lite.
Now , jumper wire pin 3 to pin 1..that should energize the relays [ there are 3 in the 000-540-67-45] and you should hear them click. If YES,
Test lamp lead at 2,7,and 8. All should lite.

Last test requires ohm meter set to continuity.

With jumper from 3 to 1 still in place , you should have continuity across pins 4 and 6. No voltage on this test , just cont. b/c it is a switch inside the OVP.

When the jumper from 1/3 is removed , all those voltages should go OFF and the cont test at 4/6 should show OPEN.
I do the jumper from 1 to 3 with a screwdriver so I can do it several times while watching my test lamp and meter to make sure they make contact every time.

If any test fail, tell me which.
If none fail, then I will tell you how to do the feed test to the OVP at the socket plug in the car that the relay connects to.

__________________
Arthur Dalton.

ps2cho · #3 03-04-2012, 02:14 PM

Honestly its not worth your time. They all fail at some point, its fact and well known. Just replace it for $50 and be done with it.

KAE or OE MB, do NOT buy URO.

gerryvz · #4 03-04-2012, 09:59 PM

DON"T buy KAE, they are not much better than URO. Just go with the factory unit, get the part number for your car at the free Mercedes EPC (sign up at epc.startekinfo.com, it's free), and order via parts dot com.

rze714 · #5 03-04-2012, 10:04 PM

Take the relay

ps2cho · #6 03-04-2012, 10:36 PM

I've had KAE in both my cars and have had no issues...Not heard of anybody who has had issues specifically with KAE OVP's?
I also disagree with including Nissens in the bad category.

URO is trying to improve their supply chain -- you can tell, but the matter of the fact is the quality of the products is yet to match anywhere near european-manufactured items. I understand they are relatively new to the game, so in the future, who knows, but as of right now, avoid them like the plague unless its a non-essential item.

gerryvz · #7 03-04-2012, 10:39 PM

To equate Kaehler products with factory MB products is a fallacy. I've personally seen Kaehler fuel pump relays for the 117 and 103 based cars fail in less than a year's time.

URO has been around for a few years now (that I know of). I have yet to see a URO product that is not a complete joke. They're not even worth giving the benefit of the doubt, considering there are far better alternatives out there.

gerryvz · #8 03-04-2012, 11:15 PM

BTW the only aftermarket brand of relay I've seen that is equivalent to MB OE quality is Stribel. Head and shoulders above KAE/Kaehler.

Adler · #9 03-04-2012, 11:48 PM

Thanks guys .I agree . I am a firm believer in replacing a ageing FPR , OVP and all the old fuses with fresh brass tipped ones and have done so . The problem is curiosity gets the better of me to find what ails the old unit.
Regards
A

whunter · #10 03-05-2012, 01:41 AM

http://www.peachparts.com/shopforum/diy-links-parts-category/209638-ovp-relay-over-voltage-protection-links.html

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