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AC/heater blower problems

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Old Mar 17, 2020 | 06:55 PM
  #16  
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I try help everyone.... unfortunately helping without seeing the truck is not always easy

I did a modification to my truck where I used a 4 port Heater control valve to control if water enters the heater core as it is hot down here in Texas and I found Vacuum lines were deteriorating in the harness .... I had to do some repairs to make sure the Blend door was working right when Heat or AC was selected ... there is a Vacuum pod that controls it close to the blower fan motor under the hood.

I had to add a Vacuum solenoid to control things when the AC is switched on.

MY truck is a 93 but very similar
 
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Old Mar 17, 2020 | 07:22 PM
  #17  
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Originally Posted by lonewolf_
I try help everyone.... unfortunately helping without seeing the truck is not always easy

I did a modification to my truck where I used a 4 port Heater control valve to control if water enters the heater core as it is hot down here in Texas and I found Vacuum lines were deteriorating in the harness .... I had to do some repairs to make sure the Blend door was working right when Heat or AC was selected ... there is a Vacuum pod that controls it close to the blower fan motor under the hood.

I had to add a Vacuum solenoid to control things when the AC is switched on.

MY truck is a 93 but very similar
You do great job helping you've helped me a ton!

Oh cool I'll have to see if found one those and do the same modification to my truck when it warms up I'm in the Western Montana mountains so it's still cold actually if garnet ghost town in Montana I live on the same mountain as the ghost town

I didn't know they were that similar that's awesome! Thank you is the vacuum pod a black ball?
 
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Old Mar 17, 2020 | 07:35 PM
  #18  
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no the Black Ball is a Reservoir IF you have one .... the pod is a Vacuum Actuator .... it uses vacuum to move a Lever .... I need to look up your specific truck for the location... but anyway it operates the Blend door between the heater core and the Evaporator.
 
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Old Mar 17, 2020 | 07:36 PM
  #19  
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Originally Posted by lonewolf_
no the Black Ball is a Reservoir IF you have one .... the pod is a Vacuum Actuator .... it uses vacuum to move a Lever .... I need to look up your specific truck for the location... but anyway it operates the Blend door between the heater core and the Evaporator.
Oh I gotcha yeah I have one of the black ***** I saw it today thanks again for help
 
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Old Mar 17, 2020 | 07:59 PM
  #20  
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yeah and I need to add a reservoir to my truck as it did not come with one......... it's more important on older trucks that use Vacuum Cruise control ... my cruise is servo controlled no vacuum
 
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Old Mar 18, 2020 | 10:14 AM
  #21  
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Originally Posted by lonewolf_
yeah and I need to add a reservoir to my truck as it did not come with one......... it's more important on older trucks that use Vacuum Cruise control ... my cruise is servo controlled no vacuum
Oh I never knew that I wish mine wasn't controlled by vacuum honestly I hope you can add one easily
 
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Old Mar 19, 2020 | 02:35 PM
  #22  
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shovelhead kid
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I just tested my blower, not sure if its original to the 88 but maybe. After replacing the blower motor resistor my fan pulled 2.6A/5.6A/8.8A/13.0A on Low/Med-Low/Med-High/High. When on high, my lights and voltage in the cab would drop indicating the fan was not getting good power or ground. I installed a relay on the brown wire that goes to the fan, using the brown wire as a 12v signal wire to operate the relay. This was extremely successful and made the fan blow harder when on high. Maybe something to look at if you also get the voltage drop in the cab when running the fan on high.


Relay wired up

blend door location and finished relay

Definitely agree with testing the blower motor directly from the battery, since the limiting factor may be the in-cab wiring.
 
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Old Mar 19, 2020 | 02:58 PM
  #23  
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Originally Posted by shovelhead kid
I just tested my blower, not sure if its original to the 88 but maybe. After replacing the blower motor resistor my fan pulled 2.6A/5.6A/8.8A/13.0A on Low/Med-Low/Med-High/High. When on high, my lights and voltage in the cab would drop indicating the fan was not getting good power or ground. I installed a relay on the brown wire that goes to the fan, using the brown wire as a 12v signal wire to operate the relay. This was extremely successful and made the fan blow harder when on high. Maybe something to look at if you also get the voltage drop in the cab when running the fan on high.


Relay wired up

blend door location and finished relay

Definitely agree with testing the blower motor directly from the battery, since the limiting factor may be the in-cab wiring.
Sweet thank you I'll check that when I get home I don't have internet at home unless I drive out to the back of my property I saved the images you sent me thank you for your help
 
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Old Mar 19, 2020 | 03:39 PM
  #24  
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Originally Posted by shovelhead kid

Definitely agree with testing the blower motor directly from the battery, since the limiting factor may be the in-cab wiring.
yeah this is the point I was trying to make
 
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Old Mar 19, 2020 | 03:44 PM
  #25  
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Originally Posted by lonewolf_
yeah this is the point I was trying to make
You guys rock!
 
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