Removing the Viscous Heater, Anyone Done It?

LibertyCRD · **Posted:** Thu Nov 04, 2010 7:59 am

Gosh, it's already a LOT smoother this morning. The viscous heater was causing repetitive harsh engagements. Sometimes it would engage so hard it would shake the Jeep....even if my HVAC was turned off. Needless to say, that is extremely annoying. I'm probably going to keep the relay pulled and the viscous heater turned off permanently now. Cabin heated up just like a normal vehicle without it.

Ripster · **Posted:** Thu Nov 04, 2010 10:57 am

The eco tune turns it off after 1/4 heat which is nice in the winter where I live. Also I had Green Diesel just
add the fog lights to the log beams in the computer as in Michigan you can have 4 white lights forward, so
my fogs are on high and low and it was a keystroke when the eco tune was done.

LibertyCRD · **Posted:** Thu Nov 04, 2010 7:56 pm

Apparently I didn't understand how the viscous heater works. Because after I really started paying attention, the cycling on/off of the clutch is still there. I guess that's the AC compressor doing that? But I had the HVAC controls set to "floor only" so I didn't think the compressor was supposed to run in that mode? This is odd....

CATCRD · **Posted:** Fri Nov 05, 2010 12:07 am

LibertyCRD wrote:

Apparently I didn't understand how the viscous heater works. Because after I really started paying attention, the cycling on/off of the clutch is still there. I guess that's the AC compressor doing that? But I had the HVAC controls set to "floor only" so I didn't think the compressor was supposed to run in that mode? This is odd....

The AC automatically kicks on in floor only and the defrost modes, regardless of the AC button.

4sefed · **Posted:** Fri Nov 05, 2010 1:59 pm

yeah I noticed that too, very lame. wish there was an easier fix to stop the ac compressor from coming on in floor mode.

having the heat blowing in your face drying out your eyes isn't really that good.

CATCRD · **Posted:** Fri Nov 05, 2010 5:24 pm

4sefed wrote:

yeah I noticed that too, very lame. wish there was an easier fix to stop the ac compressor from coming on in floor mode.

having the heat blowing in your face drying out your eyes isn't really that good.

There is a way to disable it. I've done it on mine.

http://jeepkj.com/forums/viewtopic.php?t=1265 but the board is down right now.

You can either cut the trace that activates AC or put tape there so contact can't be made with it by the rotary switch. I used tape. Easy fix.

sootyjeep · **Joined:** Fri Nov 21, 2008 12:29 pm **Posts:** 5

MrMopar64 wrote:

With the dealer scan tool, it is possible to enable low beams with high beams in the body control module.

How? By changing the country code? Please elaborate! I work for chrysler and have never tried this or haven't even had anybody ask to have it done. :POPCORN:

Quiksilver · **Posted:** Thu Nov 18, 2010 9:48 am

Hmmm very interesting

always wondered why my feet would freeze on floor mode - is this something standard on chariots? or peculiar to Jeep.

def going to take out the heater till next winter at least - and can't wait for the other board to come up to get going with my tape :POPCORN:

*Edit* just seen the time stamp on this thread - can someone get the info for the "tape A/C fix" as the KJ site doesn't look like it is coming up anytime soon

flash7210 · **Posted:** Thu Nov 18, 2010 5:11 pm

CATCRD wrote:

4sefed wrote:

yeah I noticed that too, very lame. wish there was an easier fix to stop the ac compressor from coming on in floor mode.

having the heat blowing in your face drying out your eyes isn't really that good.

There is a way to disable it. I've done it on mine.

http://jeepkj.com/forums/viewtopic.php?t=1265 but the board is down right now.

You can either cut the trace that activates AC or put tape there so contact can't be made with it by the rotary switch. I used tape. Easy fix.

Quiksilver · **Posted:** Thu Nov 18, 2010 5:30 pm

Hey Flash

Sorry - you going to have to go slower for us noobs.

Is that pic from the back of the controls on the dash?

where do you put the tape?

thnx

Edit - Found it
http://www.jeepkj.com/forum/showthread.php?t=26491

LibertyCRD · **Posted:** Fri Nov 26, 2010 12:13 pm

So I tried to reinstall the relay for the viscous heater while the engine was running and I heard a "zap" sound and now I can't tell if it's working or not. How can you tell? I actually do need the heater now because we're in ice/snow this morning.

Squeeto · **Posted:** Sun Nov 28, 2010 5:01 pm

LibertyCRD wrote:

..viscous heater .. I can't tell if it's working or not. How can you tell?

Good question. I would like to know this too.

As for the 'zap', did it come from the relay or the vh?
The relay carries a lot of current for the vh. I can believe that the contacts could arc while the relay is plugged in.

The current is highest when being energized (kind of like a 60 watt bulb that blows just when you turn it on). Also the contacts will make and break as you push it in to the socket. This could cause arcing.

Not too much of a concern. The relay contacts are engineered to withstand a little burn. Just as long as the vh is still clicking on and off when the engine is cold.

Now to find out how to test if the vh is heating.

LibertyCRD · **Posted:** Sun Nov 28, 2010 8:57 pm

So it's 40 degrees outside and my Jeep had been sitting for a few hours.

I started the engine with the viscous heater relay plugged in, and the face of the pulley was not spinning. It appeared that it wasn't running. I turned it off, pulled the relay, and restarted. Same thing. Plugged the relay back in again, started the engine, cycled through all the modes... same thing. I never saw any change in the viscous heater engagement.

The VH is the one at the upper left, right? And you can tell when it's engaged because the face of the pulley will spin, right? Or am I looking at this wrong?

flash7210 · **Posted:** Sun Nov 28, 2010 9:30 pm

Check the fuses and try a different relay in that socket.
Could be the fuse popped or relay burned up.

LibertyCRD · **Posted:** Sun Nov 28, 2010 9:36 pm

I did. I tried relays that are known to be working. No change. What's up? How can you tell this thing works?

Squeeto · **Posted:** Mon Nov 29, 2010 12:21 am

LibertyCRD wrote:

The VH is the one at the upper left, right? And you can tell when it's engaged because the face of the pulley will spin, right?

Yes, passenger side (U.S.A). It should spin and not spin, repeat.

LibertyCRD wrote:

I did. I tried relays that are known to be working. No change. What's up? How can you tell this thing works?

To check the relay, look for the connector to the v. heater (it should have one) and see if 12volts is being applied on and off while the truck is running cold.

Or pull out the relay and see if there is a diagram on the side or check the FSM wiring diagram. It should energize with 5 or 12 volts (it should say on the relay).
Listen for the click as the voltage is applied. Use an ohm meter to see if the contact side closes.

Check the fuse as flash7210 said.

Tinman · **Joined:** Mon Apr 10, 2006 10:45 am **Posts:** 308

Back to the headlight thing: There's a product call "Brite Box" that will allow the low beams, high beams and fogs to be on simultaneously on high beam. I have one on all our vehicles. Easy install.

striperman36 · **Posted:** Mon Nov 29, 2010 10:41 am

when I look at the fuse box, in the row of 4 relays is # 37 the 2nd from the side closest the windshield or the grill?

Removing the Viscous Heater, Anyone Done It?

Who is online