Modern Auto Relays

[CWells]

Can I use a modern auto relay-30 amp, 5 pin- in place of the original GM relay on my 79 C-10 for the blower motor circuit? Way, way cheaper than an original replacement style.

 

[SirRobyn0]

Can I use a modern auto relay-30 amp, 5 pin- in place of the original GM relay on my 79 C-10 for the blower motor circuit? Way, way cheaper than an original replacement style.

I have not done this, but I don't see why not. I think the down side would be possibly having to cut the wiring and soldering on new connectors. Best thing would be to get a new pigtail with that relay and solder it and shrink wrap it to the OE wires. Whatever you don't don't just butt connector it in and use crimp terminals, at least not if you like trouble free operation and plan to keep the truck.

Ask yourself another question. That OE relay is 43 years old. Do you really think that plastic relay will last 40 years? I doubt it. I replace those modern relays all the time at the shop because they go out. Personally long term I think you'd invite less future problems by using the relay that GM intended for the job. But I'm sure you can get a plastic one to work, I just don't think it would be better in anyway other than up front cost.

 

[Matt69olds]

The modern relays are sealed much better than the original parts, and without a doubt they are much more common. I have a large tote in my garage full of relays, relay brackets, and relay connectors from late model GM stuff.

You can buy the sockets, terminals and seals from places like mouser, Electrical Depot, Waytek, etc. if it were me, I’d just go to your nearest automotive salvage yard. You could probably get a handful of relays and related parts for 20 bucks. If you go that route, get as much wire from the donor vehicle as possible. Chances are you will need to cut quite a bit of wire from your truck before you get to hood solid wire that isn’t brittle or corroded.