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Heater problem

20K views 8 replies 4 participants last post by  thesanderclan 
#1 ·
I've been having this problem with a heater for a while now and finally decided to fix it. The problem is I am not getting enough heat in the interior. The fan just seems weak and the air coming out is just a little warm not hot like it should be. The rear heater is working fine. Today I took the fan out and checked it and it works fine. I flushed the heater core not too long ago too and I had it rewired so the coolant goes through it first before going to the rear heater(which works fine). The A/C was disconnected completely. I replaced the t-stat recently. The temperature gauge works fine too. Any ideas?
 
#2 ·
Maybe a door or two is not opening all the way or not at all in the A/C System. It may be why the fan seems weak. It is not blowing thur an OPEN system. Check your vacuum lines coming in from the engine to see you ARE getting vacuum to open them. I am not at home so I don't have all my info at my finger tips to check the diagram. Sorry.
 
#3 ·
It is also possible that your blend door is stuck as it is on my 90. Mine is stuck in full heat mode and I am too lazy to worry about it.

If your blend door (that adjusts the mixture between incoming cold and heater-core hot) is stuck in a position away from the heat setting, this could be causing your problem.

Somebody from a newsgroup sent me a message of how to fix it. I will have to look in one of my MANY email addresses to find it.

The other problem I have is that the cable broke off of the slide temp adjuster anyway so I would have to replace that too. Just don't feel like it. :)

Chas :blink:
 
#5 ·
Bringing tis back to the top as it is getting close to winter time and I will be driving the 90' again. I never got it fixed last year. Still didn't find what the problem was. I took off the actual fan that is behind passanger side dashboard and turned it on and it blows fine but air comes out barely warm. On the 97' it blows hot and I have to turn it down at times but 90' still sucks. I think for whatever reason the t-stat won't close after opening.
 
#6 ·
Police Interceptor said:
Bringing tis back to the top as it is getting close to winter time and I will be driving the 90' again. I never got it fixed last year. Still didn't find what the problem was. I took off the actual fan that is behind passanger side dashboard and turned it on and it blows fine but air comes out barely warm. On the 97' it blows hot and I have to turn it down at times but 90' still sucks. I think for whatever reason the t-stat won't close after opening.
That is also possible. It is quite possible that the T-stat is never closing at all.

My 90 (RIP) was stuck open when I got it and DAMM it was cold. :)

Chas
 
#8 ·
Police Interceptor said:
So how would I go about fixing it? I mean I bought a brand new one from Mopar and put it in and it still does that. I even disconnected the 2nd radiator fan so it gets hotter.
If you bought a brand new thermostat from Mopar itself, then I doubt it is sticking open.

I am not sure why it is not blowing hot air unless your front heater core is plugged up or on the way to being plugged up.

Chas
 
#9 ·
Caravan Blower Not Working Good? Here's a Fix It Tip!

http://www.autofan.com/forum_thread.asp?message=11364

Check this out by Headless Horseman on autofan.com
This Sloved my problems... Had to Cut some text out due to 10000 character limit. Refer to link above for Parts Information & installation Tips.

:ThumbsUp:



[Updated with NEW information 05-JAN-2004]...

Does your AC/Heater Blower Motor work in high-speed only or possibly some other speed as well, but NOT all speeds? Does your AC/Heater Blower Motor not work AT ALL? Or does your AC/Heater Blower Motor seem to "growl, run slow or stop altogether AFTER running for awhile, though sometimes it seems by turning it off and waiting awhile the problem resolves itself, but only temporarily? Does your Blower Motor continue to run after you've turned off your Caravan? If so, read on...

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Symptom: AC/Heater Blower Motor works in high-speed only or possibly some other speed as well, but NOT all speeds.

Probable Cause: Bad/Corroded RESISTOR BLOCK.

Solution: Replace Resistor Block.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Symptom: AC/Blower Blower Motor does not work at all.

Probable Cause: Blown FUSE, bad Blower Motor RELAY and/or bad Blower MOTOR.

Solution: Inspect fuse, replace if necessary. If the fuse is OK, I STRONGLY recommend replacing the Blower Motor Relay FIRST - this MIGHT buy you some time. Personally, I would replace BOTH Blower Motor AND Blower Motor Relay at the same time because a bad relay can cause a good motor to behave like a bad one.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Symtom: AC/Heater Blower Motor seems to "growl, run slow or stop altogether after running for awhile. Sometimes, it seems that turning it off and waiting awhile resolves the problem, but only temporarily.

Probable Cause: Blower MOTOR brushes worn, bad bearing in Blower MOTOR, and/or Blower Motor RELAY contacts are burned or pitted.

Solution: Replace Blower Motor Relay, then Blower Motor, if necessary, preferably, both the Blower Motor Relay and Blower Motor at the SAME time.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Symtom: AC/Heater Blower Motor continues to run after the engine is turned off and the key is removed from the ignition.

Probable Cause: Blower Motor RELAY contacts are "welded" in the closed position and refuse to cut power to the Blower Motor.

Solution: Replace Blower Motor Relay.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Anyone who has ever tried to troubleshoot and resolve an AC/Heater blower motor, relay and/or resistor block problem has probably shortened their lives by years. Well, I know *I* have. However, I am NOW sitting in front of my computer... after giving blood and sweat to the task and *successfully* resolving ALL issues related to my 1996 Dodge Grand Caravan LE's AC/Heater Blower problems. Print out this puppy before you attempt to troubleshoot your own problem...

I apologize for the length of this "dissertation," but I hope it covers and/or incites others to cover most common AC/Heater Blower Motor problems.

Step #1 - DISCONNECT the NEGATIVE battery cable from the battery. If you FAIL to do this, you risk shorting out a number of components that are EXPENSIVE to replace. You might also accidentally deploy either or both of your AIRBAGs which are HIDEOUSLY expensive to replace - not to mention extremely DANGEROUS with your head so close to these explosive devices!

Depending on the SYMPTOMS of your Caravan AC/Heater Blower Motor problem, you may wind up performing more than one problem resolution. Read through ALL of this BEFORE you decide what YOUR Step #2, #3 and so forth will be.

The first thing to remember is that their are at least FOUR main user-serviceable components in the the AC/Heater Blower system:

1.) 30AMP FUSE - located in the Power Distribution Center (PDC) which, for the '96 Grand Caravan, is the third 30amp fuse from the right. The inside cover of the PDC for your Caravan will show you *exactly* where your Blower Motor Fuse is located. Carefully remove this fuse (pliers are OK if you are *careful*) and look at it - if it's bad, the little "loopy" conductor will be burned out - if so, replace the fuse.

2.) RESISTOR BLOCK - located under the hood, passenger-side, above and slightly to the right of the shock tower. You do NOT have to pull this out of the firewall to inspect it. Remove the glovebox/door. You can see the Resistor Block poking through, high up, on the firewall by peering through the hole where the glovebox/door used to be. You will recognize the Resistor Block by several coiled wires (looks like a heater element) contained in a rectantagular arrangement about 3 inches wide and 1 inch high. If you see ANY rust on these coils, I suggest you REPLACE it. Removal is a PITA, but accomplished with the hood up and pulling it out of the firewall. Keep some BandAids handly. I gave blood; you might too.

@#$%&! Dodge Engineers!

3.) BLOWER MOTOR RELAY - I have considered strangling the Dodge engineer who "designed" this device to reside in its installed location. This is by far THE most difficult component to replace, but it is also among the least expensive ($8-$13)... and doing so can resolve one or more of a number of problems. Get your tools out and allow between 1-2 hours for disassembly, replacement and reassembly. No kidding. You'll need a Phillips screwdriver, a 10mm socket and ratchet with a 6-to-8-inch extension.

a.) Remove the plastic facia below the steering column (4 or 5 Philips-head screws).

b.) Disconnect the parking brake cable from the facia (make a note about how the cable is attached - you have to lift the cable up and slide it sideways/outward to remove it from the facia).

c.) Remove the stamped-steel shroud beneath the steering column - it's (the one previously covered by the facia removed in Step b.) held on by about (12) 10mm hex-head screws - make a note of the screw types and their locations, there are 2 types of screws.

d.) Disconnect the hood release latch.

e.) Disconnect the computer diagnostics connector from the U-Channel crossmember.

f.) Uninstall the U-Channel crossmember - removing several 10mm hex-head screws get this job done. Trust me, you WILL need the extra clearance to get at the Blower Motor Relay later.

g.) Remove the Junction Box cover and unbolt the Junction Box (under the dash, driver's side, it contains relays and fuses, it also has the Body Control Module attached to its back) - there are three 10mm screws, each about 3 inches long that must be removed.

h.) GENTLY pull the Junction Box as far forward as possible. Behind the Junction Box, up high and attached to a clip on the firewall, is the Blower Motor Relay. (Now you know why I have considered strangling the "engineer" for this flash of brilliance). You will recognize the Blower Motor Relay as a "black box" with four wires (blue, green, orange/black and black). It's size is about 1"x1"x2".

i.) Carefully unclip/unfasten the Blower Motor Relay with wires attached from the firewall and GENTLY pull downward as far as possible. You will notice that a plastic depression clip holds the wired connector to the Blower Motor Relay... depress it and carefully pull the Blower Motor Relay out of its socket.

j.) You will notice that the OEM part has 4 prongs and your replacement part probably has 5; don't worry, the GP Sorensen, AC Delco and Hella parts work fine - I tested ALL of them to make absolutely sure. Plug your replacement part into the Blower Motor Relay socket.

k.) Wrap a piece of electrical tape completely around the relay and its socket - this prevents dirt and dust from getting into and around the contact points and also makes it less likely that the relay will somehow work its way out of the socket.

l.) Unless you are certified masochistic, do NOT attempt to position the Blower Motor Relay anywhere NEAR its original location. The special housing that came with the OEM relay is probably NOT part of the replacement part anyway (and do NOT attempt to reuse ANY piece of the old part). Keep the relay in view while you reassemble your Caravan and tuck/tape/bind it in any way you see fit after the reassembly is complete. That's what I did. Screw Dodge engineers. Anybody feel like storming Chrysler with torches and pitchforks by now?

Hey, pat yourself on the back - you're halfway home on this one. Get a beer. Or a glass of wine. Or whatever. But only ONE. You still need to remain focused. :)

m.) Starting with Step h., - reassembly is the reverse of disassembly.

NOTE: After you have reassembled the dash, your new Blower Motor Relay should be visible underneath and behind the Junction Box/BCM... make sure it is out of the way of your feet when you drive. At any rate, it will now be a whole lot easier to replace this relay agian, should you ever need to do so.

4.) BLOWER MOTOR - located under/behind the glovebox/door. If the symptoms of your AC/heater blower problem indicates a motor replacement, take heart in knowing this is not THE most difficult task to finish. Still, I write about this because I continue to be horrified by the prices of so-called replacement motor parts - between $130-$175USD from dealers. Gadzooks. Fact is, the motor, only the motor, cost me $45USD (about 1/3 the cost of the OEM unit which also includes the motor housing and fan/cage), but requires a certain amount of "handyman savvy."

Cheers!
Go Here to read on...
http://www.autofan.com/forum_thread.asp?message=11364
 
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