Taurus fan install - circuit protection and A/C lead switch (1 Viewer)

[Spook50]

Okay I'm drawing up a wiring schematic for installing the Taurs fan once I can get one. For relays I'm using the 85A units that Lance from Pirate4x4 used for his fan, but I'm having trouble figuring out what to use for circuit protection. I've heard from several people (but found no concrete evidence) that the fan on high will pull up to 80A on spinup, but will draw only 12A while running. Another diagram I saw on a Chevy furom had both speeds each protected by 30A fuses, which the author said worked just fine and didn't blow. Would this be because of using slow-blow fuses, or can you get fuses that handle a temporary high amperage surge? Should I just stick with a 30A fuse for the power feed for each speed, or figure out something else?

Also, when looking at some of the Painless wiring kits available, I noticed a part that, according to the decription, "provides constant voltage, protects from voltage and amperage spikes and keeps fan(s) from feeding back through the system." I can't figure out which exact component prevents the feedback (I figure the relay is what they're referring to with constant voltage and protection from voltage and amperage spikes), except maybe the silver part in this pic with the two posts (which looks like an auto resetting circuit breaker, but I can't find anything to confirm it):

Last but not least, I'm wiring it up so that the fan will turn on high when I turn on the A/C. Is it the positive or negative lead that's switched on the A/C compressor? So far I figure it's the negative lead, but can someone confirm this for me?

 

[Gumby]

The silver thing is a circuit breaker. I belive a relay will prevent fan backfeed. I can look up the wiring diagram tomorrow for the AC.

 

[Spook50]

The silver thing is a circuit breaker. I belive a relay will prevent fan backfeed. I can look up the wiring diagram tomorrow for the AC.

I thought it was. If it's the relays that prevent backfeed and everything else, then my current plan has me more than covered. Woohoo!

This thing's getting 'spensive

 

[swampymarsh]

If the relay you have is a dual position relay you can wire the "at rest" contact to ground. That will eliminate the spike but may increase wear on the contact. Current Toyota wire's it that way to eliminate any feedback into the system. If the fan is not powered up when you are driving down the street it may act a a small generator and create a small voltage.

Also Battery voltage will come from the AC Amplifier to the clutch. On a FJ62 it will be a Black/White wire at terminal # 7. Dave

 

[swampymarsh]

Another thought if you want to save some cash. GM used a really really nice really during the mid 80's on most of their vehicles. These were used to operate fans, lights and so on and best of all waterproof. You can find these really cheap and generally in good condition for pennies. Sometimes even free. The terminials are easy to find at most big auto parts. You can get set up for little to no money. During the same era the were also weather tight spade fuse holders. The terminals are not so easy to fine and you may have to reuse the old ones or go to a GM store and ask for the Delphi wiring repair kit.
Hope that this helps......Dave

 

[dieselcruiserhead]

Here is my diagram. Uses two illuminated switches, one for "high" and one for "off" for water crossings. I am very happy about it, also 1 year and no problems with the thermostat, I believe because I am not running any load through it. I used 40 amp relays and do use a 30 amp inline fuse for the main power source. Works fine, I did get some water on it this weekend that blew a few of the fuses but so far so good. Honestly I think I would probably go with a Felx-a-lite wiring kit with an in-engine thermostat next time though.

 

[baloo]

As fgar as the fan drawing LOTS of start up amps ITS TRUE. I used a Tarus fan for awhile and cooked two small 30 and 45 amp relays. GO big for the relay and fuse.

 

[Spook50]

As fgar as the fan drawing LOTS of start up amps ITS TRUE. I used a Tarus fan for awhile and cooked two small 30 and 45 amp relays. GO big for the relay and fuse.

Yeah that's the plan. I plan on having an 85A relay for each speed, and was thinking a 50A MAXI fuse for each speed would be appropriate.

My wiring setup looks to be pretty damn complex, but it'll be worth it and VERY well integrated into the vehicle. LEDs to indicate what function is running and if the master kill switch is active. Full control and if it goes as planned it'll look almost stock with the control layout. I ain't f*ckin around

 

[Spook50]

Also Battery voltage will come from the AC Amplifier to the clutch. On a FJ62 it will be a Black/White wire at terminal # 7. Dave

Where exactly is the A/C amp at in an FJ62? Is it positive or negative switched?