Vacuum Solenoid problems..
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Cargo Master
Joined: Jun 2003
Posts: 3,292
Likes: 6
From: Ardenvoir, Washington
Vacuum Solenoid problems..
Not getting any vacuum out of the vacuum solenoid when switching to 4X4.. Is there a bench check a guy can do.. like ohm check, etc.. Have vacuum on inlet side only, not on the outlet to the hubs. (Transfer case is working OK.)
Hook it, I'll pull it.
Joined: May 2007
Posts: 15,037
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From: Grand Lake, La.
I don't know how to test the solenoid, but it does sound like it may be bad. I will bump this for you. If I had my truck here and my meter, I would check the connection to see what it has.
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Cargo Master
Joined: Jun 2003
Posts: 3,292
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From: Ardenvoir, Washington
Yes the pump is running OK.. I do have vacuum on the dash side and the defrost is working properly.. I have checked fuse 28 and it is good.. I am pretty sure the solenoid is the problem but wanted to make sure the wiring was working properly before I spent the money for a new solenoid.. I ohm checked the 3 pins on the solenoid and only have resistance on 2 of them..
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
With the conector pulled I got continuity between all three male pins on the PHVS.
As for the pulled connector, with key on and switch in 4x4, the center female connector had 12+ volts once the GPR switched off and the ones on either side had a ground.
As for the pulled connector, with key on and switch in 4x4, the center female connector had 12+ volts once the GPR switched off and the ones on either side had a ground.
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Cargo Master
Joined: Jun 2003
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Likes: 6
From: Ardenvoir, Washington
Hey Robin... that is great info..!! Will check the wiring voltage, but it sure looks like the solenoid is bad if you got continuity on all 3 pins.. thanks !
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
If there is an open it is most likely bad. Couldn't find a schematic for the PHVS or a wiring diagram which showed the PHVS. 
There were different ohm readings between the pins but if you have an open it doesn't really matter.
There were different ohm readings between the pins but if you have an open it doesn't really matter.
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Cargo Master
Joined: Jun 2003
Posts: 3,292
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From: Ardenvoir, Washington
Well. I checked the voltage with the key on at the plug on the 3 pins.. measuring from the center pin to each to the outer pins one at a time, I get 11.0 volts but I get the same reading regardless if the 4X4 switch is on or off.. weird? I would think there would a big difference.. seeing that this valve switches the vacuum on and off to the hubs.. Measuring from the center pin to battery ground, I get about a 1/2 volt higher..with the 4X4 switch on and off.
Robin.. what ohm range were you using when checking soleniod valve pins ? I get almost a dead short from center pin and one outer pin. But I have to put the meter to "2000K" reading to get any kind of a reading from the center pin to the other outer pin..
Robin.. what ohm range were you using when checking soleniod valve pins ? I get almost a dead short from center pin and one outer pin. But I have to put the meter to "2000K" reading to get any kind of a reading from the center pin to the other outer pin..
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Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
Well. I checked the voltage with the key on at the plug on the 3 pins.. measuring from the center pin to each to the outer pins one at a time, I get 11.0 volts but I get the same reading regardless if the 4X4 switch is on or off.. weird? I would think there would a big difference.. seeing that this valve switches the vacuum on and off to the hubs.. Measuring from the center pin to battery ground, I get about a 1/2 volt higher..with the 4X4 switch on and off.
Robin.. what ohm range were you using when checking soleniod valve pins ? I get almost a dead short from center pin and one outer pin. But I have to put the meter to "2000K" reading to get any kind of a reading from the center pin to the other outer pin..
Robin.. what ohm range were you using when checking soleniod valve pins ? I get almost a dead short from center pin and one outer pin. But I have to put the meter to "2000K" reading to get any kind of a reading from the center pin to the other outer pin..
When checkng for battery on the female connector I had the negative lead on the negative batt terminal, and when checking for ground I had the positive lead on the positive batt terminal.
Using 2000K range to get a reading is essentially looking at an open.
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Cargo Master
Joined: Jun 2003
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From: Ardenvoir, Washington
I was on the 200 ohm range when checking the PHVS pins.
When checkng for battery on the female connector I had the negative lead on the negative batt terminal, and when checking for ground I had the positive lead on the positive batt terminal.
Using 2000K range to get a reading is essentially looking at an open.
When checkng for battery on the female connector I had the negative lead on the negative batt terminal, and when checking for ground I had the positive lead on the positive batt terminal.
Using 2000K range to get a reading is essentially looking at an open.
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
I'd do the same. Seems that is the problem.
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Cargo Master
Joined: Jun 2003
Posts: 3,292
Likes: 6
From: Ardenvoir, Washington
Up-date..., I just replaced the Vacuum Soleniod with a new one (p/n 7C3Z 9H465 A)($55) and it fixed the lack of vacuum at the hubs.. The new has continuity at all 3 connections.. Thx again Robin for all your help.. !!
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
I'm sure glad that was the fix.
Thanks for the posting the outcome and the part #.
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