QuestionRoland, thanks for your advice and very prompt response.
Checked both 50A fuse in PDC and 30A fuse in fuse block - both are OK. Checked voltage at dark green blower motor wire: with ignition ON I get 12.8V and with engine running I get 14.6V - looks to be in order on the hot side at least. Tried to find the resistor block inside cabin near air intake (and every other conceivable interior location in the heater box and ducts) but can not seem to find it. Is it possibly located on the engine side of the firewall, somewhere in the right side of the cowl plenum, underneath the cowl plastic moulding? Looks like there might be something located just behind the w/w washer reservoir on the firewall, but difficult to tell without removing wipers, moulding, etc. Looks to be a perforated metal rectangular object about 1"x1", at least from the end I can see. Do not see any wires coming out on the right hand side, but could be on the left?
On a further note: Although this is not my primary problem right now, the heater output (hot air) seems to have diminished over the last year or so. I have done all the usual checks and services: drain, flush, refill with 50/50 coolant, replaced thermostat (195 degrees), checked temperature of top and bottom heater core hoses (both hot, and about as hot as top radiator hose), fans are NOT running constantly, but cycle normally after warm up (come on at about 212 deg and shut off at about 175 deg as measured in radiator filler neck). Also note that the AC system has been inoperative for some time due to a leak. The reason I bring this up, is that while currently working on the blower, I can look into the heater box and see the face of the AC evaporator. I suspect that the leak is here, as the face of the evaporator is coated with an oily grime, and pretty much obstructed due to accumulation of dirt/dust on the oily surface. Could this be the cause of poor heater airflow/output?? In carefully looking over the layout of the heater box, it appears to me that ALL air entering the heater box to the blower fan, either thru the fresh air cowl plenum or from cabin recirculation inatke at right side of blower housing, MUST first pass thru the AC evaporator to get to the heater core. Is this correct?
Again, thanks for your advice; it is much valued and appreciated!
Steve
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The text above is a follow-up to ...
-----Question-----
Roland, I have a '93 New Yorker 5th Avenue St. Armands Edition with 3.3L engine, and the standard button/lever heater/AC controls. Turned the heater blower on high the other day and ran fine for a couple of miles after startup, then blower speed slowed down, speeded back up, slowed down again for about 3 cycles then just stopped. Blower will not work on any speed setting. Needless to say, I froze on the ride home that night!
Checked blower fuse, 30 amp, No. 10 in fuse panel; not visibly blown. Also checked with multimeter for continuity and resistance; has continuity and no measurable resistance, therefore assume it is OK.
Next, went thru the laborious process of removing blower motor from under dash (should hang the guy who designed this!). Jumped blower motor with 12V battery charger; runs fine as far as I can tell - draws about 2 amps running. From many of the past problems posted, I would guess that my next check should probably be the resistor block, but can problems with the resistor block cause the blower to just up and stop as opposed to defaulting to high speed only? Can you direct me to the location of the resistor block in this vehicle, as my Hayes manual makes no mention of it at all, other than to show a typical schematic. How would I check for correct/incorrect operation of this resistor block once removed from the vehicle? Any other guesses as to what the problem might be?
Thanks much! You have a great site here.
P.S. Do you, or any of your readers, know anything about the St. Armands Edition, particularly the number actually made? I purchased this car used, and it was originally sold in Venice, Florida. Best I can find out after contacting Chrysler, is that this is an aftermarket specialty edition, not done by Chrysler. Also, St. Armands is an actual place - an upscale resort area on the West (Gulf) coast of Florida, not to far from Venice FL.
-----Answer-----
Hi Steve,
Just in case you might also want to check a 50 amp fuse in the power distribution center in the engine compartment position H (middle cartridge fuse in the inner row). If that and the #10 fuse under the dash are o.k. then you should have 12v on the dark green wire that plugs into the blower. So verify that is true.
If it is, then it has to be the blower motor resistor block. That is located in the cabin, above the glove box, positioned on the firewall high up so that the resistors are on the other side of the firewall in the fresh air intake plenum. You have to remove the glove box by removing the screws that surround the door opening which allow you to drop the box. You look thruough the dash opening and up above it you should see a quaisi-rectangular five wire plug at a rectangular plate held to the firewall with two screws.
Remove the plug and then the two screws and the resistor block will come out. Check that you have 12v on the bk/tan wire and then look at the resistor block. The resistance between the pin for the black/tan wire and the other 4 pins will vary (but should be finite). There is one resistor on that black/tan pin which if blown will shut down the blower motor entirely (infinite resistance between the black/tan and all other pins). So that is probably the blown resistor.
If that is not the case then check the slider contact in the HCAC control panel which passes the current from the various resistor paths in the block on to ground, a screw in the left side cowl (the panel to the left of the driver's leg, in front of the door opening).
You may be able to get one from a dealer or certainly from a wreck. Make sure the resistors aren't touching one another when you reinstall it.
I hadn't heard of that model of New Yorker. I think there may be build # information at Alldata.com
Let me know if any problem arrises as you check this through.
Roland
AnswerHi Steve,
I am working with the '92 wiring diagrams and assuming that they are applicable to your '93, the last year of the C-body so I doubt the location changed. I would try to follow the black/tan wire at the plug for the blower motor. It goes to the resistor block. The last place I saw for it was the right side of the cowl plenum, with the resistors sticking through the rectangular hole into the plenum, but the plug socket and base on the cabin side of the firewall, above the glove box. So if the wire goes in that direction that is where you will find it. There should also be 4 solid color wires going into the heater/a.c. control box that come from the block: they are part of a 7-pin plug on the rear of the control, at pin 3,4,5,6, so look for those wires and they too go to the resistor block. It might be mounted on the front surface of the intake plenum, in the engine compartment, as an alternative location with all the wires passing thru a grommet to get into the engine compartment where the plug would fit in the block socket. If that were the case you would see the plug in the upper right corner of the firewall.
On the air path, yes it does appear that the air goes thru the a/c core and then either direct to the cabin or thru the heater core, as controlled by the blend air door in the heater box design shown in my '89 manual, which again I have to assume is the same as in your '93. So if the quanity of air is low that could explain your poor heater performance, and also the blower might be working harder if it is trying to blow air thru and blocked passageway. The servicing appears to require about a 30 step process! to take the entire unit out from under the dash.
Roland
