Hooking up many relays

[A70Runner]

I am going to be hooking up a few relays on my car. Headlights, Radiator Fans,Fuel Pump, and probably a fan on the Trans cooler. Two questions. Where is everyone hooking to ( I know not the battery) and is anyone using a central add on hookup point?

Hope this makes sense.

Thanks!
A70

 

[rmchrgr]

I would suggest using an MSD solid state relay. It has provisions for four devices and is run off one power wire. The triggers can be on the power or ground side. Yes, it's a bit pricey but it will save you a lot of hassle. I use them, they are a nice product.

MSD Solid State Relay

On the fans and trans cooler you'll need thermostatic switches to trigger the relays.

 

[radical rob]

Either that or a small separate fuse block fed directly from the battery, that would let you fuse each circuit

 

[Sixpactogo]

I fed my fan and headlight relays with a #8 wire off of the Alternator stud. Been working fine for 6 years.

 

[RJRENTON]

I am going to be hooking up a few relays on my car. Headlights, Radiator Fans,Fuel Pump, and probably a fan on the Trans cooler. Two questions. Where is everyone hooking to ( I know not the battery) and is anyone using a central add on hookup point?

Hope this makes sense.

Thanks!
A70

When I learned electrical system components, there were two types. IEC International Electrotechnical Commission (IEC) for electrical relays, focusing on functionality, safety, and performance. And NEMA (National Electrical Manufacturing Association). The trend now is to use the light weight IEC components or the industrial NEMA rated stuff. The IEC stuff is maximum amperage/time rated where as the NEMA components are horsepower rated. My preference is the NEMA stuff as it's heavy duty and the IEC stuff looks very light duty rated. There is a significant night and day difference between the two types, with the IEC stuff is cheaper. Just my opinion.....circuit design differences are similar but maximum amperage ratings are different, especially with relays...Both types are available on line and thru ebay...
BOB RENTON

 

[gkent]

The solid state are nice but this one allows relay and fuse replacement

 

[T2R9]

The solid state are nice but this one allows relay and fuse replacement

View attachment 1898428

This is the one I use. Very nice setup.

 

[72RoadrunnerGTX]

If running a stock ammeter-based charging system, never connect loads at the battery or anywhere on the battery side of the ammeter. If not wanting to connect directly at the alternator stud, you can use a simple stud mount near the bulkhead connector, land the alternator feed on it and run another wire through a grommet to the ammeter, by passing the troublesome Packard bulkhead terminal for the alternator to ammeter feed. Load placement matters.

Alternatively, you can use a stud passthrough and connect the new alternator feed from inside of the firewall. Both approaches require a hole in the firewall be created.