Not a good idea imho. Isolate the fan power from the rest of the car wiring. Connect the fan to the battery.
Don
Don
Monster Fan Users - Quick Wiring Question
I know that VA shows the very heavy leads from the Monster Fan going directly to the battery. My car has a JEGs dual post Junction Block, one post is 12v IGN Switched (via relay), and the other post is connected to the battery with an 8 AWG that has a fused link in the feed. Just curious if anyone has wired their Monster to their 12v HOT Junction Block and if you did... why? I'm probably gonna do the straight battery deal, but figured I'd ask.
For those curious about the Dual Post Junction Block and perhaps Ground Post, this is what I used, and yes, its tied directly to the battery ground post. I wanted a decent way to ground my RS headlight electronic box and anything else up front.
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The JEGs piece is nice, even comes with a press on cover, and link if you want to make both posts hot. Its worked out great since I installed it a couple years ago.
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For those curious about the Dual Post Junction Block and perhaps Ground Post, this is what I used, and yes, its tied directly to the battery ground post. I wanted a decent way to ground my RS headlight electronic box and anything else up front.
The JEGs piece is nice, even comes with a press on cover, and link if you want to make both posts hot. Its worked out great since I installed it a couple years ago.
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Here's what I'm currently running, and no issues running two 12" fans that do draw about 30A after startup spike which is around 125A-130A from my research on these Ford/Bosch fans. Also running Vintage Air, and Electronic Box for RS motors:
1. Battery + is 2 AWG to starter and 2 AWG Battery - to engine block.
2. PowerMaster 67293 (91A idle/152A highway) Alternator to battery is 4 AWG + and its grounded to engine also with a 8 AWG.
3. Factory style ground strap on PS engine block to body.
4. PWM gets 12v from battery with 8 AWG, also 8 AWG ground to battery - post.
5. Vintage Air Red harness wire 10 AWG to battery +.
6. JL Audio Chassis Ground is connected to battery - with 8 AWG.
7. JEGs Junction Block Hot side is connected direct to battery + with 8 AWG and correct fusible link.
8. JEGs Junction Block 12v Switched is 8 AWG to 40A relay.
9. Auxiliary 100A Fuse Block (4 X 25A) is connected to JEGs Hot out with 8 AG.
Carl's PWM makes for a soft start on the brushed fans, in fact he did some testing with these exact fans and that was one of the reason I tried them. This past Sunday I drove about 25 miles on the interstate to a show and my fans only came on when I was sitting in a line waiting to get in. Snapped this shot at 65 mph after about 20 minutes of driving, car was running just over 160° and it was about 65° out that morning. Even sitting in line the temp really doesn't go over 220° with the fans running but I'm still gonna go with the Monster. I have noticed that the car is definitely running a little cooler since adding the lower closeout baffle.
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1. Battery + is 2 AWG to starter and 2 AWG Battery - to engine block.
2. PowerMaster 67293 (91A idle/152A highway) Alternator to battery is 4 AWG + and its grounded to engine also with a 8 AWG.
3. Factory style ground strap on PS engine block to body.
4. PWM gets 12v from battery with 8 AWG, also 8 AWG ground to battery - post.
5. Vintage Air Red harness wire 10 AWG to battery +.
6. JL Audio Chassis Ground is connected to battery - with 8 AWG.
7. JEGs Junction Block Hot side is connected direct to battery + with 8 AWG and correct fusible link.
8. JEGs Junction Block 12v Switched is 8 AWG to 40A relay.
9. Auxiliary 100A Fuse Block (4 X 25A) is connected to JEGs Hot out with 8 AG.
Carl's PWM makes for a soft start on the brushed fans, in fact he did some testing with these exact fans and that was one of the reason I tried them. This past Sunday I drove about 25 miles on the interstate to a show and my fans only came on when I was sitting in a line waiting to get in. Snapped this shot at 65 mph after about 20 minutes of driving, car was running just over 160° and it was about 65° out that morning. Even sitting in line the temp really doesn't go over 220° with the fans running but I'm still gonna go with the Monster. I have noticed that the car is definitely running a little cooler since adding the lower closeout baffle.
With Carl's PWM device for brushed fans the temperature sender is surface mounted to the radiator tank about 1/2" above the lower Outlet on the passenger side of the car. Thats following his specific instructions. The sensor is a 195° device and I'm currently running a 180° EMP/Stewart thermostat. The fans kick in like clockwork when my temperature gauge reads 195° without fail, so its operating perfectly.
With his new Brushless fan controller, he's using the exact same sensor setup to trigger the Spal Monster fan. The only difference is that the wire has sensor at both ends, one end is exactly like my current one, an adhesive backed 1/2" square sensor that's maybe 1/16" thick. The other end is a a heat shrunk sensor for embedding in-between the hose and the outlet. I've never use one like that before... I guess you slide it in a little past the clamp point and then clamp it down so the hose is sealed. I'm assuming the heat shrink is waterproof.
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