Combination Headlight Relay Repair?
11-29-2010, 11:11 AM
#1
Three Wheelin'
Thread Starter
Combination Headlight Relay Repair?
I've been trouble-shooting a PRND32 light illumination problem that only exists with the headlights "on". And the problem (as described) is intermittent. After headlamps are on for a bit, the PRND32 lamp illumination fails.
When the PRND32 lights fail to illuminate (with headlights on), the backup lamps fail to illuminate as well. When PRND32 lights are not illuminated, then turn the headlights "off" and presto.....the PRND32 lights and backup lamps are working again.
Grounds are cleaned, fuses are all new, CE panel has been inspected, with every CE panel cable connector removed and reconnected.
The common factor between headlights, PRND32 and backup lights are 1) the switch on the steering lock bar which seems to do its job and provide closure, and 2) a common connection between the headlamp relay, the backup light relay and the PRND32 lamp power. I don't have the schematic available now, but review the electrical diagram, and there is a common connection. Deduction: The headlight combo relay is pulling down the signal to the PRND32 lamps and the backup relay coil.
So, at almost $150.00 per new combo headlamp relay, is anyone rebuilding these?
When the PRND32 lights fail to illuminate (with headlights on), the backup lamps fail to illuminate as well. When PRND32 lights are not illuminated, then turn the headlights "off" and presto.....the PRND32 lights and backup lamps are working again.
Grounds are cleaned, fuses are all new, CE panel has been inspected, with every CE panel cable connector removed and reconnected.
The common factor between headlights, PRND32 and backup lights are 1) the switch on the steering lock bar which seems to do its job and provide closure, and 2) a common connection between the headlamp relay, the backup light relay and the PRND32 lamp power. I don't have the schematic available now, but review the electrical diagram, and there is a common connection. Deduction: The headlight combo relay is pulling down the signal to the PRND32 lamps and the backup relay coil.
So, at almost $150.00 per new combo headlamp relay, is anyone rebuilding these?
11-29-2010, 11:20 AM
#2
Chronic Tool Dropper
Lifetime Rennlist
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Lifetime Rennlist
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Alan has a diagram of the headlight relay function in his electrical systems documentation. I'm not sure if it's a simplified version or actaully reflects what's inside. Not an issue in your case though, where a contact connection is the culprit. the contacts tend to be silver-plated in better relays. You may consider taking the cover off, and looking at the various contacts for signs of pitting or damage. Better electronics stores sell a relay contact burnishing tool, something like a -very- fine file with just enough abrasive to clear a point on a contact. If the contacts are copper or brass, you can get just a bit more aggressive with the tool and actually dress it a bit.
If you end up buying a new relay, I'd be interested in having your old one. The smarts inside can't be too complex, and it may be practical to build a smart base for three standard 53B relays that would duplicate the functions of the original.
If you end up buying a new relay, I'd be interested in having your old one. The smarts inside can't be too complex, and it may be practical to build a smart base for three standard 53B relays that would duplicate the functions of the original.
11-29-2010, 11:35 AM
#3
Three Wheelin'
Thread Starter
How about this one, Dr Bob: I've been advised that the new 928.618.107.02 relay (or its upgrade) is at the moment unavailable. How about I send you my spare (purchased good-used from 928intl several years ago, and FAILED to raise the headlamps when I finally installed it recently) and you experiment with it. If you can repair it....can I buy it back from you?
11-29-2010, 06:48 PM
#4
Chronic Tool Dropper
Lifetime Rennlist
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Michael--
I wouldn't want you hanging around holding your breath for me to get the relay done. I've got a whole intake refresh sitting on the bench here in boxes for 18 months now, and lilkely will do the tb project at the same time when I get around to it sometime in the spring. My new lift is in the garage now waiting for a couple hours of attention, and the car hasn't been cleaned in a couple months.
----
Truth: I can appear to be sitting warm and cozy at home, when in fact I'm in some scattered part of the country taking a breather from a project I'm immersed in.
Fact: I've burned less than half a tank of fuel in my car (my DD) since June, so you know I haven't been around to enjoy it enough.
No longer the chair (and only active member) of the Glendale Yacht Club anymore either.
I wouldn't want you hanging around holding your breath for me to get the relay done. I've got a whole intake refresh sitting on the bench here in boxes for 18 months now, and lilkely will do the tb project at the same time when I get around to it sometime in the spring. My new lift is in the garage now waiting for a couple hours of attention, and the car hasn't been cleaned in a couple months.
----
Truth: I can appear to be sitting warm and cozy at home, when in fact I'm in some scattered part of the country taking a breather from a project I'm immersed in.
Fact: I've burned less than half a tank of fuel in my car (my DD) since June, so you know I haven't been around to enjoy it enough.
No longer the chair (and only active member) of the Glendale Yacht Club anymore either.
11-30-2010, 01:16 AM
#5
Rennlist Member
I recently bought a NEW headlight combo relay as a spare on ebay (US) for....$26.
I do have an old one that would not raise the lights sitting around somewhere, but I am in Oz. if its any use, let me know.
jp 83 Euro S AT 52K
I do have an old one that would not raise the lights sitting around somewhere, but I am in Oz. if its any use, let me know.
jp 83 Euro S AT 52K
