Heater stuck on max heat. :( - Diesel Truck Forum - TheDieselGarage.com
Thread Details Posted by bmoeller, this thread has received 7 replies and been viewed 1388 times.

 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old 06-06-2010, 10:27 PM Thread Starter
Senior Member
 
bmoeller's Avatar
 
Join Date: Dec 2008
Location: NW IL
Posts: 4,827
Points: 67,599
Thanks: 158
Thanked 392 Times in 331 Posts
Garage
Heater stuck on max heat. :(

Need a bit of help guys. Did a search and came up dry.

Got a '92 in Feb, and the heater is still stuck on. This is my first 1st gen, so I'm in new territory.

Don't know how the controls work for sure. Fan works, and the "off" button turns the fan off, but that seems to be it. Blend door moves freely, and no functioning A/C (yes it is charged, so good there).

There is a vac operated valve of some sort on the one heater hose. No vac on that line, and no change in temp with a hand operated vac pump is hooked up (and no leak down on the pump gauge). Either the valve is stuck open or,..........

Any ideas?

TIA.

"Some people are educated beyond their intelligence."

'93 W350 CC, LE, 5spd, HTT modded H1C, 4" DE

Sold- '99 3500 Q/C, SO CTD, 4x4, 5spd.

Traded off- '97 3500 C/C, 4x4, CTD

'92 W250, LE, CC, CTD w/ tweaked pump (SOLD)


"Obama = Hoax and Chains"

If Obama is the answer, it must have been a stupid question.
bmoeller is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old 06-07-2010, 03:12 AM
Senior Member
 
Join Date: Mar 2007
Posts: 1,836
Points: 19,198
Thanks: 69
Thanked 134 Times in 130 Posts
Best solution for the heater is shutoff valves - the same as a big truck, the vacuum valves often leak.

If it did not shift with vacuum - it is stuck. Turn the gauge to the control line and see if there is vacuum in the heat position of the controls, there is a plug for the vacuum supply line on the firewall above the heater blower that seems easy to unplug.

If the heater valve line switches vacuum with the control, then run a jump wire to the clutch wire on the compressor. Check for magnetic with a wrench or something, if it is tap the armature to see if the air gap is to much. If the compressor turns, then check the charge.

93 Dodge /CTD, IC, 518, club cab LE, BHAF, KDP fixed, kelderman air ride
81 Isuzu /C223na, 5spd
keydl is offline  
post #3 of 8 (permalink) Old 06-10-2010, 12:20 AM Thread Starter
Senior Member
Threadstarter
 
bmoeller's Avatar
 
Join Date: Dec 2008
Location: NW IL
Posts: 4,827
Points: 67,599
Thanks: 158
Thanked 392 Times in 331 Posts
Garage
Thanks for the help.

I already figured on getting shut off valves. Bought the fittings at the KW dealer today. Just need to pick up the valves.

Given this truck was a builder, I'm not sure what all is right or not yet. Still have a few other things to figure out.

"Some people are educated beyond their intelligence."

'93 W350 CC, LE, 5spd, HTT modded H1C, 4" DE

Sold- '99 3500 Q/C, SO CTD, 4x4, 5spd.

Traded off- '97 3500 C/C, 4x4, CTD

'92 W250, LE, CC, CTD w/ tweaked pump (SOLD)


"Obama = Hoax and Chains"

If Obama is the answer, it must have been a stupid question.
bmoeller is offline  
post #4 of 8 (permalink) Old 06-13-2010, 09:18 PM Thread Starter
Senior Member
Threadstarter
 
bmoeller's Avatar
 
Join Date: Dec 2008
Location: NW IL
Posts: 4,827
Points: 67,599
Thanks: 158
Thanked 392 Times in 331 Posts
Garage

"Some people are educated beyond their intelligence."

'93 W350 CC, LE, 5spd, HTT modded H1C, 4" DE

Sold- '99 3500 Q/C, SO CTD, 4x4, 5spd.

Traded off- '97 3500 C/C, 4x4, CTD

'92 W250, LE, CC, CTD w/ tweaked pump (SOLD)


"Obama = Hoax and Chains"

If Obama is the answer, it must have been a stupid question.
bmoeller is offline  
post #5 of 8 (permalink) Old 07-07-2010, 09:51 PM
RJC
Junior Member
 
Join Date: May 2010
Posts: 14
Points: 19,251
Thanks: 0
Thanked 0 Times in 0 Posts
Same Problem

I have the same problem with my 1993, Heater is stuck on hot also notice when i first run the truck I can see little steam coming out of the vents and windsheild fogs a little. After a while it would clear up no more steam but still blowing hot air. The previous owner had the heater core replaced about 1 1/2 year ago. Shouls i go with the valve set up like Bmoeller or is there another fix?

Thanks
RJC is offline  
post #6 of 8 (permalink) Old 07-08-2010, 12:28 AM
Senior Member
 
Join Date: Mar 2007
Posts: 1,836
Points: 19,198
Thanks: 69
Thanked 134 Times in 130 Posts
The pair of valves are used on HD trucks so that the heater core and hoses can be shut off in case of a leak and one can be turned off to stop heatin the core in warm weather.

If the steam is not from A/C condensate then there is a leak in the heater core.

That it is not spilling coolant means the leak is small - it might be cured with stop leak.

Most of the factory heater valves leak a little so adding a valve to stop coolant flow is a plan, A second valve is really not wasted - old trucks seem to use more parts than new ones. That way there is no wasted time when a heater hose or core leaks, just turn the valves.

93 Dodge /CTD, IC, 518, club cab LE, BHAF, KDP fixed, kelderman air ride
81 Isuzu /C223na, 5spd
keydl is offline  
post #7 of 8 (permalink) Old 07-08-2010, 05:10 AM
RJC
Junior Member
 
Join Date: May 2010
Posts: 14
Points: 19,251
Thanks: 0
Thanked 0 Times in 0 Posts
So is this valve available any hardware stores or is there a dealer that carries them. Looking at picture. looke like it it installed between heater hoses?

I will try stop leak but still will like to add valves?

Do you know if heater control is operated via cable?

Thanks
RJC is offline  
post #8 of 8 (permalink) Old 07-09-2010, 06:28 AM
Senior Member
 
Join Date: Mar 2007
Posts: 1,836
Points: 19,198
Thanks: 69
Thanked 134 Times in 130 Posts
Valves are 1/4 turn ball valves in 3/8's or 1/2 inch with 5/8 hosebarb adapters, I think that the ones on a Detroit are 1/4 turn 1/2 male pipe to 5/8's inverted flare.

The stock heater valve is vacuum actuated. There are cable operated valves so the amount of flow can be set but you would need a cable to work it.

Make sure the system is clean if you use stopleak.

93 Dodge /CTD, IC, 518, club cab LE, BHAF, KDP fixed, kelderman air ride
81 Isuzu /C223na, 5spd
keydl is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Diesel Truck Forum - TheDieselGarage.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
block heater and magnetic oil pan heater DZL BULL 2003-2007 6.0L Power Stroke 3 12-14-2009 01:20 PM
sometimes heat sometimes no heat WTF Superstroker 2003-2007 6.0L Power Stroke 24 02-10-2009 02:17 PM
how to check for heat stuck on defrost or 4x4 auto lock inop imported_cb44473 2003-2007 6.0L Power Stroke 3 04-17-2008 05:35 AM
Heater stuck on defrost? danktank6.9 1994-2003 7.3L Power Stroke 9 01-23-2008 04:12 PM
Little heat Birchwooddiesel 7.3L and 6.9 IDI (Pre 1994) 6 04-12-2007 02:47 PM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome