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Anonymous_User
12-11-2007, 03:38 AM
Quick question. My '99 Caravan only provides slightly warm heat regardless of engine temperature... UNLESS I put it on recirculate. Then I get nice and toasty inside. Of course, when on defrost, you can't have recirc active, so it's a pain in the arse to defrost the windshield on icy days.

I've covered all the basics... the waterpump is new this year, the t-stat is new, coolant level good, etc. If the heater core were plugged, I shouldn't get heat even on recirculate so I'm stumped.

BIGBRUDDA
12-11-2007, 09:10 AM
Its the doors on the heater fan box. Check the cable on the hot/cold slide bar( should have slight resistance,and "thunk" when closed). High boost also blows out the checkvalve at the supply line(about the size of a pill bottle. on the brake booster vac line) Check for vac at the control buttons.:thumb:

TurboRon25
12-11-2007, 02:35 PM
I thought the 99ish caravans had electric motors to move the doors. With the key on and everything off, moving the selector from feet to dash to def I could hear this little electric motor sound. For sure on my 2000, I think I also did it on my 97.

Ron

turbovanmanČ
12-11-2007, 05:22 PM
Its the doors on the heater fan box. Check the cable on the hot/cold slide bar( should have slight resistance,and "thunk" when closed). High boost also blows out the checkvalve at the supply line(about the size of a pill bottle. on the brake booster vac line) Check for vac at the control buttons.:thumb:

99 Minivan is turbocharged? :confused:

It could be the core is plugged but in recirc, your rewarming the inside are so it doesn't work so hard. I would confirm the heat doors are closing. Check the temp on the heater hoses, the inlet should be very hot, the outlet should be warm.
i am just going thru this on a customers 95 Grand Prix, soaked the heater core with CLR, now has heat, :thumb:

Anonymous_User
12-12-2007, 02:45 AM
I would confirm the heat doors are closing

I suppose this is the best place to start. Van has split heat (driver/passenger) and both sides when turned to full heat are the same temp. But, no assumption is better than a direct observation.


soaked the heater core with CLR, now has heat

Most likely the course of action I will take over the weekend.