blower resistor saga

I have another twist on the continuing issues with caravan blower resistors.
Mine went a year ago and I replaced it then with a oem resistor
all worked well until recently now the blower works in low, med low and high.
it does not work on medium high speed.
I replaced the resistor block with an after market one which did not fix the issue -
I returned it.
I've checked all the wiring and all appears good - no melted or corroded parts I can see.
I removed the centre console and spayed contact cleaner into the switch itself.

any suggestions are appreciated.

What year?

If a late model automatic or manual HVAC.

The blower motor is ground side controlled meaning the switch controls ground (older models up to 99/00 or so). So with a test light hooked up to power you can check the wires at the resistor connector. you should find a wire that illuminates for each speed setting. If nothing illuminates for the speed that doesn't work than the switch is bad.

Make sure the connector/connections are not burnt up at the resistor also.

Sorry
2003 Grand Caravan Sport Edition, 3.3, 3 zone controls, manual temp control.

Is it possible the resistor would fail on one speed setting?

low speed uses all three resistors,(works)
medium low - two resistors,(works)
Medium high, one resistor (fails)
high - no resistors (works)


thanks for the help, I'll try the test light approach

You said you replaced the blower resistor and it did not fix it. So that would lead me to believe its not the resistor. If you want you can check continuity of the various pins of the resistor.

If you put one test lead on pin six and check continuity on pins 5 , 3, 2, & 1. There should be continuity between all of those and pin 6 all the time. If one does not show continuity then you found your burnt resistor. Pin 4 is power in for the blower motor and there is no continuity between pin 4 and the other 5 pins.

This might help.

This might help.

it will significantly -----
thanks

Looking closer at the schematic, which is different from an earlier one I looked at, each speed clearly has its own resistor.
It seems from this layout that one speed could easily fail and not impact other speed settings.
It could be that the replacement resistor was defective.
I'll try another one.

jpb53 - Your wiring diagrams look familiar. Are your getting these off the ARRC site? If so how do you copy them to get them here. I've tried the usual copy/paste mode but can't get it to work.

I download to my desktop then upload from there. Yes it is from ARRC. It is available from our state library. You can also access alldata at our county libraries using their computers. ARRC is available to a lot of people from their public library but most people don't or won't try. Google is your friend!!!

for the record - my problem is (was):crying: the resistor.
Seems the replacement I got the other day must be BO as well.
I bought another one at a different supplier (Partsource - a shoot off from Canadian Tire Stores) and things worked ticky-boo now.

thanks for the help.

The resistor I bought little over 12 months ago just crapped out. I'm going to the dealer for my next one.