TJ blower fan help

[blthomas]

I'm on the struggle bus with anything electrically. I like to try and learn, so I watched a bunch of videos on meter basics, and trouble shooting stuff.

Wife's TJ that I'm resurrecting, was off the road 8 years. Lots of stuff to fix and I'm getting down to the small things.

So no heater fan on any speed.

I printed a diagram from a forum.

Big fuse #11 in the PDC tests good with a meter and test light.

I pulled the fan itself, spins well when directly connected to battery.

Behind glove box, the HVAC relay has 12v coming in, relay clicks when pulled and connected to battery with jumpers. I tried using the meter on it while following a video, appears to be ok using his method.

Went to check the small #8 fuse behind the glovebox, no reading on my meter, no go on the test light.

I did the tests key on engine off, does the motor actually need to be running?

I pulled the controls apart, nothing is melted or burned, apparently that's a big problem on TJs.

I got nothing at the harness going to the switch, key on engine off.

Tried swapping fuses in small fuse #8 slot
and also tested the fuses with the meter, and they appear good. They certainly look good.

Thoughts? Nothing appears chewed, connections look decent. Not sure where to go from here. Thunder storms rolled in, so online to do research.

Edit it's 1998

Thanks

 

[NDCjeepsmith]

Have you tried jumping the 12V in to any of the fan power in wires at the plug on back side of switch?

Kinda sounds like your switch may be non op

 

[TrikeKid]

You didn't mention a year so I pulled a diagram for an 02. You should have 12v key on power at all times on one in of the relay (comes from PDC Fuse 1, 40a) and keyed power on another coming from fuse 8 in the under dash fuse panel. The blower motor grounds through the resistor, and that grounds through the switch. Pull the connector at the blower motor resistor and look for melted shit. The resistor is usually where a fan control circuit will fail, lots of heat and current flow going on.

 

[blthomas]

Have you tried jumping the 12V in to any of the fan power in wires at the plug on back side of switch?

Kinda sounds like your switch may be non op

I just got out to mess with it. Jumped from battery to switch plug, only high works. None others. Plug harness into the switch, nothing happens. Key on engine off as these circuits are only powered with ignition on right?

You didn't mention a year so I pulled a diagram for an 02. You should have 12v key on power at all times on one in of the relay (comes from PDC Fuse 1, 40a) and keyed power on another coming from fuse 8 in the under dash fuse panel. The blower motor grounds through the resistor, and that grounds through the switch. Pull the connector at the blower motor resistor and look for melted shit. The resistor is usually where a fan control circuit will fail, lots of heat and current flow going on.

Its a 1998, sorry about that. I'm using a diagram from a forum. I realized today I don't think I have keyed power on, fuse 8 won't light up on my test light with key on. Cant get a reading to ground either. Figure that should read 12.4+ right?

Fuse looked good yesterday, changed it out too.

I do have power coming in on a leg from the PDC to the relay, fuse in PDC lights up test light too. They all do.

Could I be losing the 12v signal at the ignition switch? Its not exciting the circuit and that's why I can't get 12v at fuse 8 under dash?

I didn't realize so many wires went into the ignition switch, I read that the hazards are on their own so they'll work key on or off, but I have no hazards either.
Or wipers...

I'm gonna go pull the resistor.

 

[blthomas]

 

[blthomas]

Guessing this is worthless looking at it. Wondering if this looks this bad, would I just be ahead buying the switch too. The pins look clean, but betting the inside of the switch looks bad too. Same thing at the ignition. Dunno.

 

[Rockwood]

I just got out to mess with it. Jumped from battery to switch plug, only high works. None others. Plug harness into the switch, nothing happens. Key on engine off as these circuits are only powered with ignition on right?



Its a 1998, sorry about that. I'm using a diagram from a forum. I realized today I don't think I have keyed power on, fuse 8 won't light up on my test light with key on. Cant get a reading to ground either. Figure that should read 12.4+ right?

Fuse looked good yesterday, changed it out too.

I do have power coming in on a leg from the PDC to the relay, fuse in PDC lights up test light too. They all do.

Could I be losing the 12v signal at the ignition switch? Its not exciting the circuit and that's why I can't get 12v at fuse 8 under dash?

I didn't realize so many wires went into the ignition switch, I read that the hazards are on their own so they'll work key on or off, but I have no hazards either.
Or wipers...

I'm gonna go pull the resistor.

It’s most likely the resistor. It’s cooler by the air blowing through the system, but gets clogged with shit, overheats, and lets the smoke out. Usually you get a fun ghosts of electricity smell before it stops.

 

[Rockwood]

Guessing this is worthless looking at it. Wondering if this looks this bad, would I just be ahead buying the switch too. The pins look clean, but betting the inside of the switch looks bad too. Same thing at the ignition. Dunno.

Well shit, yeah. This. Go to Vatozone and get another.

 

[blthomas]

It’s most likely the resistor. It’s cooler by the air blowing through the system, but gets clogged with shit, overheats, and lets the smoke out. Usually you get a fun ghosts of electricity smell before it stops.

I probably should have just started replacing all this shit from the get go. It sat in the humidity of Virginia for 8 years. Betting my hazards problem is a rusty pin or some shit too. Same thing with the wipers.

 

[TrikeKid]

I probably should have just started replacing all this shit from the get go. It sat in the humidity of Virginia for 8 years. Betting my hazards problem is a rusty pin or some shit too. Same thing with the wipers.

Yeah TJ multifunction switches really don't do well with moisture. They're surprisingly bad for a rig designed to run with no roof/doors.

 

[cj3a]

On my 2006 the resistor would only last a few years before I changed the blower motor. I was also bad on leaving the fan on low all the time. I now wish I could figure out why my mirror display stop working.

 

[JohnnyJ]

On my 2006 the resistor would only last a few years before I changed the blower motor. I was also bad on leaving the fan on low all the time. I now wish I could figure out why my mirror display stop working.

why bad to use low?

I believe our 2005 TJ has the bad resistor as it only has 3rd and 4th speeds left. Was just looking at some youtube troubleshooting videos last night. I figured I'd load up the parts cannon and start fixing the issue.

Yeah TJ multifunction switches really don't do well with moisture. They're surprisingly bad for a rig designed to run with no roof/doors.

Yeah, this is on the list, too.

 

[cj3a]

why bad to use low?

I was running the blower all the time when not needed since about 2006.

 

[Rockwood]

I probably should have just started replacing all this shit from the get go. It sat in the humidity of Virginia for 8 years. Betting my hazards problem is a rusty pin or some shit too. Same thing with the wipers.

Also: Chrysler. I swear the electrical engineers thought they were sending these things to the Moon with the minimum wire gauge selection for everything.

why bad to use low?

I believe our 2005 TJ has the bad resistor as it only has 3rd and 4th speeds left. Was just looking at some youtube troubleshooting videos last night. I figured I'd load up the parts cannon and start fixing the issue.



Yeah, this is on the list, too.

Bad because the airflow is slowest and resistance (heat) is highest.

 

[JohnnyJ]

Also: Chrysler. I swear the electrical engineers thought they were sending these things to the Moon with the minimum wire gauge selection for everything.


Bad because the airflow is slowest and resistance (heat) is highest.

I guess by the early 2000s I woulda thought they had this figured out, but I guess not. Not like they were only OEM burning up motor resisitor switches.

 

[Gregj50!!!!!]

My 03’s blower motor makes the dying goat noise when turning on/off….
looks like I’ll be tuning up the whole system by the sounds of this thread!!!!!!

 

[blthomas]

So as a update, the resistor was shot, I bought a switch too, but it had the wrong diameter post for the knob to push on.

But we have good hot heat, and four blower speeds.

Next items are, only have defrost, and off, no other positions work.

All the actuators under the dash look like shit. If I move the selector should I feel vacuum at one of those while the engine is running?

Mice did eat the vac line coming through the firewall, I've replaced it when I did the heater core.

Any proper way to test the multi vacuum connection at the back of selector switch? Its not a tight fit, one side has broken plastic retainer. Wondering if that's enough to kill the pull of the vacuum.

Also no wipers at all, no hazards but have full functioning turn signals at all corners, and switch works otherwise for high beams.

Both of those are new as well as the ignition switch.

I'm guessing I need to sort where the voltage stops for the hazards and wipers.

PDC is hot, fuses behind glove box are cold ignition off, hot key on.

On a 98' is there two flasher relays? I only see one.

Thanks for all the help so far.

 

[cj3a]

I have not dealt with that stuff yet. I keep getting a small evap leak check engine light. Plan on throwing some parts at it this weekend. I have already changed the fuel pump and filler neck which had rotted out.

 

[blthomas]

I have not dealt with that stuff yet. I keep getting a small evap leak check engine light. Plan on throwing some parts at it this weekend. I have already changed the fuel pump and filler neck which had rotted out.

My small evap leak code went away after I replaced the canister itself (found a small crack) and a section of soft line on the frame.


So I did a bunch of wire testing and chasing.

I've got 12v at the wiper switch from fuse box. Pulled the cowl and I've got 12v at motor harness, flipping the wiper switch pushes voltage to the corresponding pins for high and low. I think the motor is toast, I can't turn it with vise grips on the stud going to wiper arms.

There is a wire from PDC into the ignition switch, its the direct 12v for hazards if I read the diagram correct. That pin is dead. The pin for switched 12v from the mini fuse block works. So I took apart the PDC, and started in tapeing wire.

I found a swollen section on the hazard 12v wire. Is that a fusible link? Anyway to test other than cutting it out? I really don't want to pull it all from the loom.

Thanks

 

[blthomas]

So I forgot about the fat wire as its under the PDC. I went to put in the battery, I had stripped sheathing on the other side of engine bay, I wanted to see if I had current at the firewall.

Knocked the PDC on its side, and I poked that wire and it popped. Cut It out, repaired, I have voltage now in my other test location. Hoping I have hazards, but column is torn apart, ran out of time tonight.