NO power to blower 40 amp fuse caravan

[dodge wizard]

Well heres my story and I hope someone can help.

I own a 2003 SXT caravan and the front blower worked fine till yesterday and no nothing.
Does not work on any setting including high.
I have swapped 40 amp fuses, still does not work
I have swapped relay and still does not work.
I removed the resister and it looks fine so I testing for volage on all pins going to the resister and no power to any of them.
So then I removed the 40 amp blower fuse and checked for voltage at either tab and nothing, no voltage.

So my question is : Is the 40 amp CB the first place power enters the circuit?
And how does the IPM get its power?

All other items on the van work, no other problems.

Thanks Kevin

[RIP]

The closest schematic I have is for a 98 and it doesn't show a 40 amp fuse or an IPM (?). Check Alldata, Mitchells, Chiltons, or Haynes. The auto repair guys at About.com can sometimes help. Have you tried an advanced search here? Welcome to the forum.

Hey. We're human. You had the ignition to "on" or "acc" when you checked for voltage right?

[dodge wizard]

Car was running and tried all settings

[Stretch58]

My prints for a 2000, shows the 40 amp front blower fuse in the PDC gets its power straight from the batt.

[hundahunta]

in the pdc remove the blower motor relay. pin 86& 30 are power from the battery pin 85 is a blower motor relay control from the fcm, pin 87 feeds your fuse also make sure the accessory relay is ok.

[dodge wizard]

OK , I have only power to 86 and 30 with the relay out with the relay in half way so I can check voltage I got voltage to 85. I have no voltage to 87 with the relay still plugged in but up alittle so I can check. It sounds like a bad relay but I have swapped it with the defogger relay and accessory relay and it still does not work.? Almost there i appreciate the help.

[hundahunta]

pin 85 should be ground...

[Stretch58]

Originally Posted by hundahunta

pin 85 should be ground...

Agree, if you have voltage on 85 with the relay still making contact there is continuity thru the relay coil but there is no ground. I would remove the relay, making darn sure you are on the front blower relay(there is a pin 85 on almost every relay) verify there is now no voltage on 85 and check to see if you have
continuity to ground with the Ohms X1 function. If not, you need to find it.

[dodge wizard]

OK, I am on the front blower relay and fuse, Ive doubled and triple checked, its printed right on the cover. I checked a good caravan today ( I had access to)and with everything running I had power to 86/30 and 87 and 85 had no power.

Now, mine I just checked to verify what I had and with van running and blower on I have power on 86/30 and 85!! With no power on 87!

I also checked ground from 85 to ground and its open. I checked 87 to ground and theres continuity.

[dodge wizard]

85 goes to #30 in the front control module is that whats giving the problem?

[hundahunta]

ok heres all the diagrams


FRONT BLOWER MOTOR RELAY CAV CIRCUIT FUNCTION
30 INTERNAL B(+)
85 FCM 30 FRONT BLOWER MOTOR RELAY CONTROL
86 INTERNAL B(+)
87 C7 12DB FUSED FRONT BLOWER MOTOR RELAY OUTPUT
87A - -



BLOWER MOTOR RESISTOR C2 (MTC) - BLACK 2 WAY CAV CIRCUIT FUNCTION
1 C70 12DG REAR BLOWER HIGH SPEED
2 C7 12BK HIGH SPEED BLOWER MOTOR

BLOWER MOTOR RESISTOR C1 (MTC) - BLACK 6 WAY CAV CIRCUIT FUNCTION
1 C75 12DB/GY BLOWER MOTOR HIGH DRIVER
2 C74 12DB/WT BLOWER MOTOR M3 DRIVER
3 C73 14DB/VT BLOWER MOTOR M2 DRIVER
4 C7 12DB FUSED FRONT BLOWER MOTOR RELAY OUTPUT
5 C72 16DB/OR BLOWER MOTOR M1 DRIVER
6 C71 16DB/BR BLOWER MOTOR LOW DRIVER

[dodge wizard]

Sorry I dont know what that all means let alone finding it

[Stretch58]

Originally Posted by dodge wizard

85 goes to #30 in the front control module is that whats giving the problem?

Not sure what you are talking about #30, and what front control module?

[dodge wizard]

Ok thank for the help but Im this far Il make it easy from pin 87 of the relay to ground it Ohms out and as I adjust the fan speed the ohms go alittle higher and lower. (this is with everything off) So I believe that whole circuit works fine.(resister, fuse everything in the interior)

What I dont under stand is Im getting voltage out of in 85 instead of 87 thats why its not working. My dodge manual shows pin 30 from the FCM(Front control module) goes to pin 85. On a working caravan 85 had no volts and 87 feed the circuit the opposite of mine.

Any last help?

Thanks

[1thunder]

jump pin 30 and 87 and presto every thing works but you will need to determine why the front control module isnt groundind pin 85