Electrical relays

[Guest]

I would like to test all the relays in my 1988 Porsche. I had one fail recently and it took ages to find the problem. I have now lost the live feed to my fuel pump and my left hand electric window has stopped working. I understand that I can buy an instrument to test each relay. Anyone know what it is called and where I would buy one?

Regards, David.

 

[Guest]

David,
The relays aren't that expensive; I keep about 1/2 dozen spares, and simply swap em around! Don't kcuf with em.
The door window could be same as mine - the switch it self needs cleaning - they pull apart. Remove from door, dissconnect the 1/4 inch spade terminals. Prise the top lid off the switch with a small flat blade screwdriver. Carefully take top off. You'll see 2 brass pivot arms inside, with contacts on them. I cleaned all these contacts, then I tinned them with a coat of solder. Clean flux off, and reassemble. Fixed. Takes around 10 minutes.

 

[Guest]

I cleaned all these contacts, then I tinned them with a coat of solder

Did they have solder on then already ? Normally, they don't, as solder does not make a good, moving, contact material (too soft). This is most noticable on the two contacts of normal, BC, mains light bulbs, which are fixed, but, even then, they wear away.

So, this might just be a temporary fix.

 

[Martin Perry]

dissconnect the 1/4 inch spade terminals

...and do something to make sure you know which way they go back on afterwards! I got through several fuses on a trial and error basis before finally making some sense of the Haynes manual wiring diagram.

Martin

 

[Guest]

One good thing about disconnecting/reconnecting the spade connectors, is that this quite often cleans them/removes any oxidation that has built up over the (many) years. Of course, any extra cleaning with fine abrasive can't but help. Also, check that the spade connectors still grip the pin firmly, although too much tightening can make them a b*gg*r to get back on !

These components tend to carry large currents, and, at 12v, any small resistance causes an appreciable voltage drop.

 

[Guest]

John,
your point about the solder is a good one.
I own a dremel - ( best electric tool you could buy).
I use the dremel to lap the contacts inside the switch & clean all the 1/4 terminals, and just to ensure the suface is at the right hieght I add a lick of solder. Ok, it might last 2 or 3 years, then wear down, but hey, it takes 2 minutes to pull the switch out and rip the top off!
As for wiring the connectors back, the colour coding is easy to remember.
Your referance to voltage drop - yes - dead right - thats why I advocate the use of relays - ie, the high beam headlights - bung a 30 amp relay on em and stand back! Its that easy. All this waffle about xeon bulbs and so on... if anyone needs proof - hook up a headlight direct to the battery, at night and just look at the differance!
A blind man could tell,
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