12 Jan 2024 5:33 pm
tldrGHETTOBLASTER » 12 Jan 2024, 5:41 pm » wrote: ↑ It's replacing the highly specialized and vehicle specific switches that make keeping these older cars roadworthy a chore.
What you want to do is to send the current carrying "power feed" wire of the heater fan through a high enough amperage relay..and use a standard duty toggle switch at the dashboard to energize the relay. When the relay energizes, it has an internal switch that allows current to flow to the fan motor.
Let's say your heater fan is originally protected by a 25 amp fuse..then you want to choose at least a 25 amp relay [or higher] to act as the actual switch that feeds the heater fan.
To control the relay you will only need 18 gauge wire that travels up to your dashboard mounted toggle switch.
Do all of your heavy duty circuits [like your headlights, engine electric fan, electric fuel pump and even your ignition switch] similarly.
with a full sized truck you have plenty of room for a plastic kitchen cutting board to mount your relays. Cut the board to size with a hack saw and use sheet metal screws to mount the relays to the cutting board.
A toggle switch panel you'll find on-line or else make one from a 2 inch wide by 4 foot long piece of aluminum ruler you can get at Harbor Freight.
Do not ever buy or use HF automotive fuses though...they will cause more problems than they solve.
Always buy BUSS brand fuses and good quality toggle switches...not the plastic Chinese crap.
Wire nuts work just fine for automotive splices [if done correctly] and HF wire nuts are OK. I think they sell an assorted size pack.
Otherwise you want to make the connections with "ring style terminal lugs" and use a pair of wire strippers and a "lug crimper" to handle that chore.
HF insulated wire is OK too. I would not use it to wire up a missile silo or to do the controls at a nuclear power house, but that wire is good enough for a car.
10 gauge wire for 30 amp loads [like a heater fan or headlights]
12 gauge wire for 20 to 25 amp loads
14 gauge wire for up to 15 amp loads
16 gauge for up to 10 amp loads
18 gauge for up to 5 amp loads. this is a easy to work with size to go from your toggle switches down to energize your relay coils
HF Tyraps are OK.
9 out of 10 MAGA RIOTERS agree that HF Ty-raps were good enough to almost hang Pence and seize control of the US Government with.
