Rear heat question

General technical discussion and troubleshooting
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SteveTR6
I am merely driving my van
I am merely driving my van
Posts: 15
Joined: Mon Jan 17, 2011 8:42 am
Location: West Chicago, IL

Rear heat question

Post by SteveTR6 »

2003 Astro AWD LT, 156k miles. Within the last 2 weeks, the blower resistor failed, followed (almost immediately after replacement) by the blower motor. Fixed all that, now have perfect heat again in front. For the last few months, the rear heat has not worked. I bypassed the solenoid by routing the manifold (incoming) vacuum hose directly to the heater valve, which worked for a while until the valve failed and started puking coolant. Last week I replaced both the solenoid and the valve with new parts. After install, I get no hot air to the rear. I let the thing run for a loooong time (also driven it 50+ miles), made sure the coolant was full, everything. Front blows burning hot air, rear about 70 degrees. Today, I decided to pull the manifold vacuum line off the solenoid to make sure it's not plugged with coolant from when the valve failed. As soon as I pull the hose, I hear it hissing (good!) and the rear starts blowing hot air. Now I think I messed up somehow.
Can somebody please tell me the CORRECT way to hook up the vacuum lines? As in, how did Chevy do it? I installed the manifold vacuum tube to the top nipple on the new solenoid, and the bottom nipple I connected to the nipple on the valve. Obviously, that's not right....
Thanks
Steve
2003 Astro LT AWD, dark carmine red, newest family member
2002 Astro LT 2WD, pewter -- gone but not forgotten. head gasket at 209k did it in
1994 Astro CL EXT, traded at 150k for the 2002
2000 Jaguar XJ8L, wife's daily driver
1981 Goldwing, naked, my daily driver 8+ months out of the year
1980 Vespa P200, wife's toy
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