syoo8

I searched 499 threads with the word "relay" in them but didn't come up with any solutions-- wondering if the wise (wo)men on the board can offer advice.

I recently replaced all of the "cheap" relays in the CE panel. These were relays marked "53" (part number 141 951 253 B) & "21" (the flasher relay, part number IHO 953 227.) I think they were inexpensive because they are used on Audis as well?

The terminals from the old relays (original, I am sure) were corroded in some cases and so I cleaned all of them and applied Stabilant for good measure. After cleaning the old relays and replacing all of the "53" and "21" relays, I got a nice qualitative bump in the dash voltmeter.

I then checked prices of the 928-specific relays. The prices starting getting rather... interesting. When I added up the prices (pulled from my favorite 928 parts supplier) it looks like I'm going to have to drop over $1K... (Prices included below.)

My questions are:

1a) How crucial is it to replace 24-year-old relays, especially when they showed corrosion on the terminals?

1b) How frequently do you all replace your relays?

2) Given that many of these relays are proprietary, and 928s are now 15+ years out of production, are there other solutions other than to spend $1K to replace these relays? Are there equivalent relays available at electronics parts warehouses, etc?

Hilton

1a) Unless they've failed, not crucial

1b) When they fail (I carry spares of some in the car, like the 53-type, and ABS relay which I picked up for $10 brand-new in a surplus parts sale)

2) My other solution was a small aerosol of Deoxit contact cleaner. I open up the relay (e.g. headlight double relay), spray all the contacts with it, leave for a few hours, then spray with CRC's CO Contact Cleaner (its a residue-free contact cleaner). If the corrosion looked too bad, I used some 2000-grit wet'n'dry, and fold a tiny strip of it in two so both outer surfaces are rough, then insert between the relay contact pads on each of the reed switches.

Ispeed

I would change them every 24 years.

S4ordie

Relays are binary. They either work of they don't. I'd carry a a couple of the common ones as spare. The biggest thing is to occasionally clean all contacts. Very important to exercise great care in the removal and replacement of the relays when you clean them. It is very easy to damage the case and the internal connections.

I too am interested in the idea of quality alternative pricing for some of the more expensive relays. Of course quality is paramount.

jon928se

They either work or don't until they only work when cold or when hot or when the humidity is right etc etc etc.

Replace the 24 year old cheap ones, the 53's - keep the old ones as spares. You'll have to make your own choice as to wether you replace or buy new spares for the more expensivve ones.

The 53 relays cover the mission critical stuff for your car - I'ld perhaps add the headlight and wiper relays to the spares list. Everything else can be done without but you still get to drive home in relative safety.

StratfordShark

We were discussing this on UK owner list yesterday, and a pro electronics guy pointed out the important point that electrical component reliability followed a curve where failures where concentrated in early life of the part, and went very flat after the "burn-in" period.

On that basis seems sensible not to put yourself back in danger area of curve by replacing unless there's been a failure, and instead to carry a good quality spare for the key 53 relays.

911tracker85

a few weeks ago I went on a PCA rally that took us WAY out in the coutry to cross several old wooden covered bridges built in the late 1800s.

I was driving my 911 on this as the 928 work not finished yet. only one shark in the pack. very nice red/saddle interior.

out in the middle of nowhere I come on him stopped. it was an S4 but did not ask the year. he had a couple spare relays (but no DME relay) and nothing we did worked. engine turned over fine and would get an occasional hit, so symptom was fuel not spark. he finally called the flatbed. very sorry to see, and I stayed with him until he decided to call the tow.

ROG100

A lot of the relays are only available from Porsche as the low volume does not warrant the wholesalers buying from the OEM.
If it is a Porsche part you are in for a shock. Prices for some parts went up significantly in April.
As an example 928 615 115 00 nearly doubled in price to $162. $89.95 seems like a bargain.

syoo8

Thanks for your advice S4ordie, and everyone.

I guess the premise of my original post is that apparently I was suffering from some voltage loss in the CE panel at the hands of old relays. Replacing the old relays (whose terminal contacts were just cleaned) with the 8 new "53" relays really helped matters. This is what led me to believe that I should change all of the relays.

Thanks Roger for chiming in. I assume that prices for 928 relays are never going down, correct? If this is the case, is it prudent to buy a set of the Porsche relays now?

dr bob

For the S4+ cars, what's on the list of 'specialty' relays? I see the headlight relay as a possible mission-critical device. I replaced the wiper relay a year or two ago with the solid-state VW part and have the original in the spares box. The others that really see loads (X, LH, EZK, FI, FP, foglamp) are all 53B's so relatively inexpensive.

Besides the HL relay, which have folks needed to replace?

928 at last

Dr Bob,
What is the part number for the VW unit, and if I may ask, what models/years was it used in??
I'm just building up a stock of mission critical spares.
Thanks!

Alan

Rob - I'd not call Intermittent Wipers a mission critical feature (not even the parking features that it also controls) - but it is a nice convenience and cheaper and much better than the Porsche version..

https://rennlist.com/forums/showthre...eferrerid=6055

Alan

928 at last

Thanks Alan!
I thought the relay was for the wipers themselves.
and it's not mission critical until you get caught in a monsoon and wind up sitting on the side of the road till it passes!

dr bob

Rob--

I bought the 'programmable' from Roger a while back. I generally don't drive in the rain (SoCal) so I wasn't sure what I really needed if for, but did it anyway. For the drive from L.A. to Texas for OCIC last year, the feature was interesting but not essential; It allows much longer intervals than the stock system, a plus. But the setting mode includes operating the washer pump and spraying the glass. No big deal if it's already raining I guess, but less than ideal IMHO. I'm not set on making it original again, but I do have the original relay in the 'spares' box JIK.

Bill Ball

Over the life of my car I've had to replace just the headlight combination relay. I carry a spare 53. That's it. You mention corrosion on the blades. I've seen some other cars that have this. Mine doesn't. My car isn't babied but it is garaged at night. Thus, it isn't exposed much to the wide swings in temperature that can produce condensation that seems to wreak havoc with these cars. Some cars suffer even worse effects from water in the CE panel area due to leaves and other debris plugging up the cowl drain near the blower motor, and this may require extensive work on the CE panel wiring and connectors to fix. So, I think the need for pre-emptive relay replacement and other electrical re-conditioning is affected by the way the car is stored when not in use.