12V switched power source - hookup

[JOHNFAK]

Hey guys

Trying to get my tranny cooler installed this weekend.

On my auxilliary cooler - it has 2 wires , about 9 inches each - 1 black and one blue. It just says to connect this to a switched 12V power supply.

How do I do this ?? Never have before.

I assume I could run 1 wire (blue) +ve terminal and 1 (black) to negative terminal - and it would get power every time the engine started - but I would prefer to activate via switch - ideally something like the existing A/C switch.

Is it easy to hook up to the A/C switch somehow so when I turn the A/C or FAN on - it engages the fan on the auxilliary cooler ??

OR seperate switch from o'reilly's/electronics store ??

Need full details - and quite basic details - not overly good at reading wiring diagrams etc

thanks guys

--- Update to the previous post...

Kinda thinking I need to not install the thermostat - as it kicks in at 180 and I might want to start cooling a little lower than that. (As if I am 180 on COLD line where thermostat is - then I am 220+ on HOT line out).

So then I am thinking I could use some sort of 12v toggle switch with inline fuse in the cab ?

So - can I tap into an existing 12 V wire and then just run the black wire to a ground - or do I need to run the black wire all the way back to the negative terminal ?

If I can tap an existing wire - any ideas of best one ? Easiest to locate and splice ? Or should I run it from the bagttery direct ?

[ISX]

I am not entirely sure what you have. You still have the stock engine fan on it right? This tranny cooler is some separate radiator thing with a little fan on it? If it is a little separate thing with a fan on it I would leave the thermostat hooked up. It might somehow get hot when you don't expect it to and the thermostat would keep you covered there. I would go direct to battery with it.

[Mopar1973Man]

What I did for key power source is tapped one of the switched +12V fuses in the cab and ran it to a relay as a trigger and powered the relay from the battery so now I've got a key switch +12V power source that does no harm to the stock wiring and such.

[JOHNFAK]

I am not entirely sure what you have. You still have the stock engine fan on it right? This tranny cooler is some separate radiator thing with a little fan on it? If it is a little separate thing with a fan on it I would leave the thermostat hooked up. It might somehow get hot when you don't expect it to and the thermostat would keep you covered there. I would go direct to battery with it.

ok - here's what I am gonna do I think. Run power from baterry to my two pronged toggle switch in cab one one prong, with a inline fuse inbetween. Then continue power to my fan. Then Take negative/ground from fan and bolt into the frame for ground/complete circuit. Make sense ?? Is that ok ?? I am not going to use the thermostat for 2 main reasons - (1) The parts are a little flimsy and I am sure they will last but the less is better for me - I like the idea of an auto switch with the thermostat but it only turns on at 180 degrees (cold IN line). When I am at 180 degrees on cold line I am 220 on the hot line. I believe from what I have read (not what I know) that ATF starts to degrade at 220+ ... so really I'd like to engage the fan a littler earlier when not locked up. 2) So I am setting my alarm on my edge HOT line sensor to 210. Then with the manual switch - I just flick it on and cool it down until temps back down , or locked up on highway. That way I have both an alarm and a mechanism for turning t off/on whenever I want Let me know if that makes sense and approach ok. Mike - don't quite get that - not because of any reason than I just don't know. So you tapped a 12v fuse similar to the way you tap a fuse for edge (piggy back) ...... and you ran to relay - you mention trigger ? I guess the fuse gives you the power and the relay activates the circuit ? Curious on some basic details of that. thx guys Gonna post two threads soon with some pics - one of my tranny cooler hookup - and the other of my front end detail/paint - both came out pretty good in the end ciao john

[AH64ID]

Why not just find a colder temp switch? Or find a way to locate the temp switch in the hot line. Personally I like the auto idea, I would use a 3 position switch. On - Off - Auto

[Mopar1973Man]

Why not just find a colder temp switch? Or find a way to locate the temp switch in the hot line. Personally I like the auto idea, I would use a 3 position switch. On - Off - Auto

Actually safer yet... On - Auto Skip the OFF idea... Like on my Goldwing Motorcycle if I know I'm going to be trapped in traffic I flipped the coolant fan to ON. But if I flipped the switch the other direction to AUTO then I knew if I forgot the coolant fan would come on if I spaced out and wasn't paying attention to coolant temps...

[AH64ID]

Actually safer yet... On - Auto Skip the OFF idea... Like on my Goldwing Motorcycle if I know I'm going to be trapped in traffic I flipped the coolant fan to ON. But if I flipped the switch the other direction to AUTO then I knew if I forgot the coolant fan would come on if I spaced out and wasn't paying attention to coolant temps...

True.. I still think with the off-road mentality that "OFF" is a good idea on fans.. but with the OE clutch fan you can't turn it off, so stopping fans is a mute point.

[JOHNFAK]

thanks guys - didn't think about the other possibilities (on/auto ....... and on/auto/off). I was worried about the lack of control with just having the 180 degree thermostat - I like those other options. Unfortuantley for now that would mean cutting my lines again (its too tight to pull off) and a bit of a process - so for now think I am going to stick with the on/off option and consier revisting those options later. Given that - is what I said with a two prong toggle the way to do it ? Don't quite get mikes fuse/relay deal - only cause I have NEVER hooked up any type of switch before. So for right now - safest/simplest is best. So .... 1) (+ve) battery-> inline fuse -> first prong on switch in cab -> second prong then continues +ve supply/wire to fan2) negative/ground wire on fan is then just bolted into frame for ground. that work ?

[JOHNFAK]

*bump* Anyone have any more comments ? Is doing that way ok for first approach ?? Don't want to have to cut all my tranny lines to get the thermostat back on until I am somewhere more conducive for working on that (in rv park). So ....1) (+ve) battery-> inline fuse -> first prong on switch in cab -> second prong then continues +ve supply/wire to fan2) negative/ground wire on fan is then just bolted into frame for ground.that work ?

[AH64ID]

Sounds like it will work well for just on/off.

[JOHNFAK]

cool thx mangoing to try it today.I wish I had thought abut the auto/on/off - didn 't even cross m mind. But the cooler is tight up behind the transfer case between frame and driveshaft and to get the tubing off in order to get the thermostat on will probably mean I will have cut and replace the whole line - still might do that - but will go with this first.Just wasn't sure if there was a better way to do the on/off. eg tapping into the a/c switched power or anything - but definately simpler is better right now.will let you know.

[JOHNFAK]

HeyAll worked fine - thx guys Can I do a 'thread request' between you lot - electronics 101 - and make it a sticky. BE good to not allow to many comments on it .............. really just a info page. Things like how to work with switches, sensors, electronics on your vehicle. Voltage - resistance OHms etc Things that I am not 100% sure about - as a starter include 1) Why does grounding complete the circuit - eg why don't you need to take back to the -ve terminal of battery.2) Open ended wire - how do you tell if its 'HOT' or not3) How to use a multimeter properly - eg it has various voltage and resistance settings , 1V,2V,12V,120V etc4) How to measure voltage of wire if its fully connected and you don't want to cut it ?? 5) Same for resistance etc ? 6) How to tell if their is noise/irregularity in the signal7) How fuses work - with regard to Amps - eg I hooked up a 30AMP between my switch - but would 15A been better ? etc

[AH64ID]

Congrats!That would be a great thread, and I can almost see ISX drooling over the opportunity!Just a few quick answers (some take longer)1) Your frame is tied directly to the neg side of the battery, so the whole frame/body/etc is "grounded" just the way the system works. In a DC (Direct Current, like in auto's) the electricity must flow back to the source, so when your reverse lights come on the power leaves the battery (or alternator) and goes thru the switch down the wire to the light, then thru the light into the neg wire, to the frame and back to the battery thru common grounds. 2) With a multi-meter, wiring diagram, or screwdriver style electrical test light. 3).. Those manuals are long! I have been using once since I was a kid and am still learning!4) They make adapters for multi-meters that put a pinhole in the wire to test voltage, small enough for voltage to flow, but not big enough for water. 5) Same for resistance. 6) You will hear feedback in the stereo, otherwise no clue :shrug:7) Fuses work off the fact that electricity makes heat, so the fuse melts and the circuit becomes incomplete it if flows too much electricity and gets too hot.

[JOHNFAK]

Thanks man Any links to these adapters you mention to pierce the wire to get voltage etc ? Fuses - but what determines if you use a 5/10/15A or a 30A ? ....... I wasn';t sure what the rating was on my fan so just went with a 30A as its seems to be around the highest for 12v.

[guesswho512]

Thanks man Any links to these adapters you mention to pierce the wire to get voltage etc ? Fuses - but what determines if you use a 5/10/15A or a 30A ? ....... I wasn';t sure what the rating was on my fan so just went with a 30A as its seems to be around the highest for 12v.

my grandpa always uses needles(maybe for sewing, i don't sew) that are a "T" and claps alligators to that to test wires. you can use a multimeter to see the amperage. or see from the manufacture how many amps the said device is rated for

[AH64ID]

I don't have a link.. been too long to even know what they are called. But I will be trying to borrow the old mans here in a month or so. As for fueses, most things electrical will tell you how much they draw. So for my on board air compressor it draws 19 amps max, I think I put a 30a fuse in to account for minimal jumps in load for motor start. I am sure the fan on your cooler has a rating on the fan and/or box, probably in the 5-10 amp range.

[JOHNFAK]

thx guys

[Mopar1973Man]

6) How to tell if their is noise/irregularity in the signal?

The correct way to check for AC noise is use a oscilloscope to see the noise ride on the DC voltage.

[Rogan]

The mathematical (technical) way to determine fuse size is the Power Formula Wheel:[ATTACH=CONFIG]1741[/ATTACH]but I think 30A is quite large. I usually run the wire-gauge method:16-18g = 10A14-16g = 15A12-14g = 20A<12g = suggested minimum fuse ratingI'd also run a relay, and allow the toggle to trigger the relay, and fuse the relay's input, rather than allow the toggle switch to carry the load, since most switches aren't rated much above 5A-10A load.

[JOHNFAK]

thanks man !! good stuff Someone exaplain relays ??? In a very basic way., I have NO IDEA. I bought a 120V 10A switch from home depot - thats the one I am using http://www.lowes.com/pd_75666-1071-161U_0__?productId=1100285&Ntt=toggle+switch&pl=1&currentURL=%2Fpl__0__s%3FNtt%3Dtoggle%2Bswitch does that mean I only need a 10A as the switch itself is 10A ? I guess I still need to confirm the 'A' of the fan Any drawback to using a 30A fuse when all you need is a 10 A ?? Guessing something to do with it won't break the circuit early enough if their is an issue and result in the thing your trying to protect breaking ?