Does anyone know where I can buy a quality relay?
Or have advice as to how I can solve this problem?
I have a GM vacume pump on my car and I am on my 2nd relay going bad.
The vac. pump is on a 30a fuse that has not blown, it seems the points of the relay go bad after about 600 miles of driving?
All connections are crimped soldered and heat shrink, grounds are good.
I know it's the switching on/off that's killing them but don't know how to fix the problem other than trying to find a better relay.
The first relay was the type that had the green rubber weather seal to keep moisture out, so I thought it would be good, the points on the load side burnt out on it.
I am sure that's what's happening to the one I have in there now.
I thought of trying two relays but dont know if that would solve the problem?
Thanks T.C.

I like Bosch and Hella relays. Are you using a automotive style relay? Does it have a built in diode? What is the vac pump used for? How many amps does the vac pump draw? How often is it switching on and off? There could be lots of reasons why they are not lasting very long.

Does anyone know where I can buy a quality relay?
Here are two places, but there are many others.

http://www.route66supply.com/
http://www.waytekwire.com/bosch-relays.htm

Thanks for the replies and the links:
The vac. pump is for brakes and is GM, as I stated it's protected by a 30a fuse.
So it's not drawing 30a or it would be popping the fuse, also this time I am using NAPA 30/40a relay.(I ASSume automotive style relay)
As to how many times it switches?
How many times do ya hit the brakes?
T.C.

You could always grab some OEM ones at the wrecking yard. Good quality and cheap!

My son has the vacuum pump on his Chevelle as well and we have it going through a 30/40amp Bosch relay with no problems and it's been approx 2 years now and I'd guess 2500 miles. Hey I bought a bunch to lower the cost. If you want I'll send you one and see if it works for you, cost free. Pete

BPG-Inc.com is where I got mine.

Hey thanks for the offer Pete, It's a very nice gesture.
If I cant find one local I may take ya up on it.
I'm at about 3500 miles and on number two, 1st was Tyco brand, 2nd was NAPA.
T.C.

Just because it does not blow the fuse does not mean it is not pulling higher current. It just means it does not pull a higher current long enough to blow the fuse.

Electric motors are horrible for this. At initial turn on they pull huge currents and then the current drops off as the motor spins up to speed. My electric fans for example pull 70A at startup and 15A while running. That initial surge results in the arc that burns up contact points.

Much as points used a condenser to reduce arcing, a condenser could be used on the relay to make the contacts last longer.

What do you all think about the solid state relays?
http://www.route66supply.com/store/page76.html
On this web site, kinda pricey
T.C.

i'm with ray, go to a junkyard and fill a pocket with relays from euro cars that depend heavily on quality electronics: newish bmw's, mercedes, jaguars and the like....i read somewhere that they have the best relays, plus, if they dont last either, you're out very little, one other thought, check a gm manual for a vehicle with that setup as original, could be you (or whoever) overlooked something on installation ....good luck

Thanks again for the replies
Kinda hard to find the old books on the vacuum pump(84-86), electrically it's just one red and one black wire going through a vacuum switch and a relay.
The vacuum is one inlet and one outlet.
But the junkyard relay idea is worth looking into.
T.C.

I'm on the same page as Vrooom. Arcing is wearing the contacts. I had a similar problem of wearing out micro switches for reverse and neutral safety on my Megashifter (at $11 each). I soldered a small capacitor across the terminals of each switch and it was solved. I used metal film because I had 'em laying around, but ceramic disc would work too, something on the order of 100uF would be a good place to start. Visit you local Radio Shack. Condenser is automotive word for capacitor.

Thanks for the advice on the caps, I have a ton of them all different sizes.
I have also had one "blow up" in my face, so I am trying to fix the problem w/o going that rout.
I'm thinking I may have had a poor ground?
I painted the core support with POR 15 silver then POR 15 black, I think I thought the silver was the metal when I cleaned for the ground wire?
There is no question I am on the metal now, so if I have another relay go out I will either go with the solid state relay or try the cap's.
T.C.

Note that ground connections should always have a serrated washer between the electrical terminal and the body/frame metal specifically for that reason. The serrations are intended to puncture the paint to make metal to metal contact.

I had the special washer on there, it's just the POR 15 is so tough I wasn't 100% sure.
Now that I have ground away the paint with a air tool I am sure I have a good ground.
T.C.