- Location
- Billings MT/Rapid City SD
On my 89 I just cut the temp sensor wires from the rad. and ran a switch/solenoid from them.
-
Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.
Quick bypass switch for stock aux. electric fan
- Thread starter YELLAHEEP
- Start date
Ralph
NAXJA Member #149
- Location
- Lubbock, Texas
On a 96 model the relay is energized on the ground side. Simply run a wire from the ground side of the relay from under the relay box to a switch and then to ground. When you flip the switch you energize the relay and turn on the fan. No muss, no fuss. Works fine and lasts a long time.
Hellbent
NAXJA Forum User
- Location
- san diego, california
Ralph said:
this sounds good, going to try this when i get home tonight. thanks!
Israel
NAXJA Forum User
- Location
- Spanish Fahrk, Utah
CODevilDog said:
X2. I did this on my 96 for a couple weeks until I was able to replace the fan clutch. There is a wire connected to the back of the AC compressor which I disconnected. After that, if I needed some extra cooling, I would set the interior controls to AC and it would turn on the fan, but not the compressor. Kind of sucked not having AC for that couple of weeks, 'though.
Yeah but I was hoping for some sort of way to keep the stock temp turn on in case someone other than me drove it...i practically need to write an instruction manual on how to drive the damn thing. It turns on with temp right now, but not AC. It's a 98 btw if that helps.Jess said:
- Location
- Houston, Tx
Israel said:
:yelclap: I was just about to ask if I could do this.
Ok fella's here is the deal.
When Troy was having over heating problems I walked up when someone suggested "hot wiring" the fan. The suggestion was to run a hot from the battery to the fan + so it would run at all times. I then said to Troy that there is a fan relay and we could put in a switch so that he could run the fan when ever he wanted. My thought was that I would put a switch in the cab that would supply power to the + side of the coil for the fan relay. This would run the fan any time he wanted but also make it so the fan would run automatically when the switch was off. Troy said it wasn't worth the effort because he was going to fix the real cause of the problem which was a marginal radiator. But he still was having over temp problems. That's when I figured it would be easiest to just pull the relay and jump it so it ran. We did that and it took care of his problem. The only reason that jumper wire was hot was from the under hood temps, not from too much current. Then when in the store I saw the switch and thought it would fit, which it did. That made it much easier for him to turn it off and on durring the week.
I never checked to see how much the fan circuit was rated for but it really didn't matter because this was temporary and it worked just fine. Also, with the size of the relay in there I'm guessing that switch would be no problem at all no matter how long you left it in there.
That said, the problem with this set up really is the check engine light. If pulling the AC relay and running the AC causes the fan to run with no other ill effect that by far is the best solution for a temorary fix. Troy thought it was pretty cool though because it looked so neat and tiddy for a temporary fix.
B
When Troy was having over heating problems I walked up when someone suggested "hot wiring" the fan. The suggestion was to run a hot from the battery to the fan + so it would run at all times. I then said to Troy that there is a fan relay and we could put in a switch so that he could run the fan when ever he wanted. My thought was that I would put a switch in the cab that would supply power to the + side of the coil for the fan relay. This would run the fan any time he wanted but also make it so the fan would run automatically when the switch was off. Troy said it wasn't worth the effort because he was going to fix the real cause of the problem which was a marginal radiator. But he still was having over temp problems. That's when I figured it would be easiest to just pull the relay and jump it so it ran. We did that and it took care of his problem. The only reason that jumper wire was hot was from the under hood temps, not from too much current. Then when in the store I saw the switch and thought it would fit, which it did. That made it much easier for him to turn it off and on durring the week.
I never checked to see how much the fan circuit was rated for but it really didn't matter because this was temporary and it worked just fine. Also, with the size of the relay in there I'm guessing that switch would be no problem at all no matter how long you left it in there.
That said, the problem with this set up really is the check engine light. If pulling the AC relay and running the AC causes the fan to run with no other ill effect that by far is the best solution for a temorary fix. Troy thought it was pretty cool though because it looked so neat and tiddy for a temporary fix.
B
- Location
- Houston, Tx
My a/c compressor is unplugged, and i confirmed yesterday that turning on my a/c now only turns on the e-fan
Ummm ok, didnt read all the posts here but some are over thinking this whole thing...... if you just need the E fan to turn on and off just un plug the ground on your AC pump (just the ground lead on the top of the compressor) and use the AC controls on your dash. As for all the other problems yall are having on fans not turning on and such, all your rigs are diffrent years so sensors, placement of sensors and types of sensors are diffrent.
Renix- uses a temp accuated *on-off* switch in drivers side of radiator to run the E fan
HO- Uses a signaled switch on the thermostat housing that tells the computer to turn the fan on and off.
Pretty much figured all the diffrences between the pre 90 and post 90 because I swapped my pre 90s cooling system (sensors and all) to a post 90 so if any need to know how to upgrade the renix cooling systems, I got the sensor part numbers and list of all parts "needed".
Renix- uses a temp accuated *on-off* switch in drivers side of radiator to run the E fan
HO- Uses a signaled switch on the thermostat housing that tells the computer to turn the fan on and off.
Pretty much figured all the diffrences between the pre 90 and post 90 because I swapped my pre 90s cooling system (sensors and all) to a post 90 so if any need to know how to upgrade the renix cooling systems, I got the sensor part numbers and list of all parts "needed".
Israel
NAXJA Forum User
- Location
- Spanish Fahrk, Utah
Actually, I think the thread started as some good, on the spot, quick thinking to keep a rig going through the rest of it's trip and then suggestions on other ways to skin that same cat were made. All good ideas in my opinion.
I tried unplugging the ground and running it, didnt turn the fan on. Tried neither, and still nothing. Does the jeep have to be running for this to work? Ive been putting it in the on position and i tried unplugged ground and engine on...everything seems fruitless.
I do think the Jeep must be running and not just turned on. Try that and it may help you. I know if my Jeep is running hot enough for the fan to run and I turn off the Jeep the fan stops. If I then turn the key to run the fan does not come on. Then if I start the Jeep the fan runs again. Mine is a '98. So I'm thinking you must have the Jeep running. Plus I think the Jeep must be running for the AC compressor to cycle on so it would stand to reason that the fan won't come on until the Jeep is running.
HTH,
B
HTH,
B
I thought that might work but i tried it with both the ground and power unplugged, then one of each, both while the engine was on. I have no idea, is there a fuse somewhere that could be shot? I know that it kicks in when the temp gets to 220F or so.Bloose said:
