Where can I find heavier relays, 80 amp?

I've got an electric fan mounted (a spare from another car I have). The thing is a 2 speed fan, and it pulls a pretty decent load (eats 30 amp fuses instantly, I'm told it draws around 60-70). I have the low speed run through a controller, but I'd like to run the high speed to a switch. The problem there is that both sides cannot be running at once or it will burn it up. I've made a standard 30 amp SPDT relay work, but I'm worried about it burning that up. I'd rather have something I know will standup to it. Anyone have a source for a relay that's rated around 80 amps?

Have a look at the PAC-80 here: https://www.pac-audio.com/products/productsCatagory.asp?mmSearch=Battery%20Products

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Wire 30A relays in parallel.  That will probably be your cheapest and easiest solution.

When wiring contacts in parallel you add their current capabilities together.

hi,

bosch has 75A relays .... available on ebay for around $25 with shipping.

mark

Thanks for your suggestions.

On that PAC-80, it's hard to tell by the pictures (even downloaded the pdf manual), but does it have both the open and closed outputs? The relays I found on ebay all lack the open output (the 87a pin, as do pretty much all of the relays you can buy locally it seems...).

Being that I can only have 1 on at a time or risk burning it up, the most obvious way to me was to use the closed output (87) to run the high speed, and the open (87a) to run the low speed controller. I could do this with a couple relays in parallel though, I hadn't even thought of that.

Close.... it's from a T-Bird SC. From the look of those pictures, it's the same fan except the shroud on my fan is smaller (the SC uses a thicker, skinnier downflow radiator to make room for an intercooler). I had an extra one to slap on my base model T-Bird. Sounds like it draws about the same amperage too. The stock alternator on this thing is only a 75amp, so the voltmeter made me nervous at idle the first few times... I have a 3.8 mustang engine around here, and those have 130 amp alts, so I'm going to see about it next. It'll require a little rewiring though, as my stock one has a plug for the B+ output rather than a post (and it has 2 B+'s on that plug....).

That diagram looks like a better option. I essentially had mine going the same route through that center relay, just needed to go one step further (adding the bigger relays after it). Just have to add my fan controller between the low speed output and the fan itself and I'm good (don't want the fan running all the time, takes too long to warm up if I do). Thanks.

Have you looked to see how Ford controlled it?.. On those, there's usually a control module mounted to the radiator support that has a bunch of relays in it.. you could use that if you got the wiring diagram for it.

Jim

why not just use a starter relay. Other name starter Solenoid

hi,

starter solenoids are typically rated for intermittent duty only, not meant to be left on.  power contactors can be designed for intermittent or continuous duty.  https://www.stancor.com/wrdstc/pdfs/pg98.pdf

hope this helps,

mark