It's damn hot in my truck. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

70 shorty · 01-16-2005, 04:48 PM

I got the heater core replaced this wknd. Obviously it's not an everyday truck or I would have done it earlier. Anyway, you could sit in that thing with shorts on and be warm. In fact it started freezing rain as I was working on it. I did the heater core itself in the garage, but figured I'd better hook the hoses up outside, coolant always seems to go everywhere. Now the only other main thing is to get the dash lights working. The only light at all in the cab is the display on the stereo.

Longhorn Man · 01-16-2005, 04:51 PM

Something I discovered on the 'ole GMC, even thoguh my heater put out a butt load of heat, the cab leaked enough that you were always cold, onless you were putting around town. And that was without any holes in the floor.

Russell · 01-16-2005, 05:33 PM

My GMC is the same way, I've got a bunch of holes in the firewall where gromets are missing / I made holes for EFI wires etc. In my spare time I've collected the gromets / made firewall junction boxes and stuff to seal it back up. If I set it to Heater, it keeps things midly warm, if I set it to defrost, it heats up the top of the cab, but my feet are freezing cold all the time, lol

Tx Firefighter · 01-16-2005, 05:49 PM

Shorty, if you have no dash lights at all, the headlight switch may be bad or the fuse for the instrument lights. It's not likely that all of the bulbs in the dash would be bad.

shuttermutt · 01-16-2005, 10:22 PM

You know, I put a new heater core in my 68 about 14 months ago. It used to blow so hot that you couldn't touch the center outlet (my truck has A/C), but now it's just barely lukewarm. I'd noticed that the truck didn't seem to get up to operating temperature anymore so I figured I had a bad thermostat. I put in a 195 degree 'stat today and let the truck warm up to full operating temperature, but that center outlet still just blows lukewarm at best and the truck just doesn't get warm at all. Sure, it's been hovering right around zero here, but I suspect something more insidious is at play. Anybody have ideas?

ddsmith · 01-16-2005, 10:31 PM

Diverter doors not operating properly maybe. The cable hold downs may be loose allowing the normal operation of the temp control slider without giving the corresponding door movement. The hold downs are what makes the cables function properly. It is also possible that the cable is bent which normally happens when the cables get old and no longer move freely inside the wire sheath. Good luck on figuring it out.

ABHaulR · 01-16-2005, 10:38 PM

my heater works great, 12 deg outside in the mourning when i leave, have to take my jacket off around 5 miles down the road or i'm sweating.
Dwayne

68C15 · 01-16-2005, 10:43 PM

where have you been Greg? it sounds like you have a problem with the temp door or cables like ddsmith said. my truck gets hot enough to roast a turkey. do you have sufficient air flow? (plugged evaporator fins)
as mine is a non AC cab I set the controls between def & heat so that my hair & my feet will spontaneously combust at the same time.
bring it over here in the spring for the meet & we can look at it.

shuttermutt · 01-16-2005, 11:55 PM

Yeah, I'll play with that flap a bit while I'm waiting for the engine to warm up tomorrow morning. I can't think of any reason other than those flaps that it shouldn't be roasting me out of there like it did last winter. Once I get that fixed, I'll turn my attention to the screaming/growling blower motor and the windshield washer that only seems to want to spit instead of spray. Why does it wait until 0 degrees to pull these stunts?

useRc10 · 01-17-2005, 12:12 AM

70 shorty- check the bulbs before you go pulling anything else apart...i found in mine that they are like x-mas lights...one burns out and they all go

72 Cheyenne K20 · 01-17-2005, 12:57 AM

I have a 70 w/air and had the same prob with the heat. There's a valve on the pass side inner fender that only A/C truck have that was gummed up and not letting an circulation thru. I replaced the valve and have more heat than I can stand.

orange72 · 01-17-2005, 01:05 AM

lol i thought i was the only one with that screaming motor...you can hear that thing a mile away.

shuttermutt · 01-17-2005, 01:11 AM

Valve on the passenger's side inner fender, eh? I'll look again, but that doesn't sound familiar. Was it a vac operated contraption, perhaps? Any idea what it's called or what it does?

Oh, and you're certainly not the only one with a screamer, orange72. Mine has a personality. It's either dead quiet (75% of the time), growling (15% of the time) or screaming like a banshee getting its butt hairs ripped out (10% of the time). I've heard it's a bear to replace that motor so I'll probably wait until it fails altogether.

Longhorn Man · 01-17-2005, 01:17 AM

The blower motor isn't hard to remove, but you DO have to remove the hood hinge. After that it's a matter of a few bolts.
To prolong the blower motor's life, drill a small hole in teh center of the metal 'hub' portion, and spray some graphite in there, then a dab of black RTV to cover the hole. I did this on the 'ole GMC the day I bought it, and to this day it works fine...well, at least it did in Oct when i got rid of it.
That valve on the inner fender is a vac operated valve. it turns the coolant flow off all together so when you turn on the A/C there is no heat in the heater core.

72 Cheyenne K20 · 01-17-2005, 01:21 AM

the valve is vac controled. Looks like the book is calling it a shut-off valve. If I can get a pic I will post it.

wanted · 01-17-2005, 01:59 AM

Mine would only blow warm air. I idled the truck with radiator cap off for awhile to get the air out and now the heater is baking hot.

Americanrider · 01-17-2005, 03:57 AM

Once had an old CJ5 Jeep with a firewall that looked like swiss cheese. Got mad one day and plugged them all with plain ol' bathtub caulking, (the only thing I had at the time) it's easy to remove if I wanted to run another wire and no more engine fumes. You can paint it over too!

01-16-2005, 04:48 PM	#1
70 shorty Where's my beer? Join Date: Oct 2004 Location: Glen Allen, VA Posts: 1,772	It's damn hot in my truck. I got the heater core replaced this wknd. Obviously it's not an everyday truck or I would have done it earlier. Anyway, you could sit in that thing with shorts on and be warm. In fact it started freezing rain as I was working on it. I did the heater core itself in the garage, but figured I'd better hook the hoses up outside, coolant always seems to go everywhere. Now the only other main thing is to get the dash lights working. The only light at all in the cab is the display on the stereo. __________________ 70 C10, shortstep, .30 over 250,Hurst shifted 3 spd parts hauler. Holley 390, Clifford Intake, Header, ported cylinder head, unknown bigger cam. 79 Corvette L82, 4 spd, black, red interior, headers, flowmasters, and unkown bigger cam. '03 Grand Cherokee Laredo, 4.0 4x4 daily driver. 165K miles, and runs great '08 Tahoe LTZ 4x4 155K

01-16-2005, 05:33 PM	#3
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	My GMC is the same way, I've got a bunch of holes in the firewall where gromets are missing / I made holes for EFI wires etc. In my spare time I've collected the gromets / made firewall junction boxes and stuff to seal it back up. If I set it to Heater, it keeps things midly warm, if I set it to defrost, it heats up the top of the cab, but my feet are freezing cold all the time, lol __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

01-16-2005, 05:49 PM	#4
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Shorty, if you have no dash lights at all, the headlight switch may be bad or the fuse for the instrument lights. It's not likely that all of the bulbs in the dash would be bad. __________________ I'm on the Instagram- @Gearhead_Kevin

01-16-2005, 10:22 PM	#5
shuttermutt Don't say "Oops!", Doctor Join Date: Nov 2003 Location: Houston, TX Posts: 677	You know, I put a new heater core in my 68 about 14 months ago. It used to blow so hot that you couldn't touch the center outlet (my truck has A/C), but now it's just barely lukewarm. I'd noticed that the truck didn't seem to get up to operating temperature anymore so I figured I had a bad thermostat. I put in a 195 degree 'stat today and let the truck warm up to full operating temperature, but that center outlet still just blows lukewarm at best and the truck just doesn't get warm at all. Sure, it's been hovering right around zero here, but I suspect something more insidious is at play. Anybody have ideas? __________________ 'Mutt 1968 CST LWB: R.I.P. 1967 Chevelle: TPI 454 beast 1967 C10 SWB: Claimed when Bumpster didn't put it on his list

01-16-2005, 10:31 PM	#6
ddsmith Glowing since 1978 Join Date: Mar 2001 Location: Lusby,MD,USA Posts: 532	Diverter doors not operating properly maybe. The cable hold downs may be loose allowing the normal operation of the temp control slider without giving the corresponding door movement. The hold downs are what makes the cables function properly. It is also possible that the cable is bent which normally happens when the cables get old and no longer move freely inside the wire sheath. Good luck on figuring it out. __________________ 66 Chevy C30 Stakebody Dump, PS,PB, 327cu in 71 Corvette Coupe 454 4 speed 69 Chevy C20 Custom Camper

01-16-2005, 04:51 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Something I discovered on the 'ole GMC, even thoguh my heater put out a butt load of heat, the cab leaked enough that you were always cold, onless you were putting around town. And that was without any holes in the floor.

01-16-2005, 10:38 PM	#7
ABHaulR Registered User Join Date: Jun 2003 Location: West Valley City, Ut Posts: 311	heat my heater works great, 12 deg outside in the mourning when i leave, have to take my jacket off around 5 miles down the road or i'm sweating. Dwayne __________________ 72' GMC Suburban 10 1/2" of Lift, 40" Tires! Waiting for restoration 67' Chevy, What to do??? And Bad Ass American Bulldogs!

01-16-2005, 10:43 PM	#8
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	where have you been Greg? it sounds like you have a problem with the temp door or cables like ddsmith said. my truck gets hot enough to roast a turkey. do you have sufficient air flow? (plugged evaporator fins) as mine is a non AC cab I set the controls between def & heat so that my hair & my feet will spontaneously combust at the same time. bring it over here in the spring for the meet & we can look at it. __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card

01-16-2005, 11:55 PM	#9
shuttermutt Don't say "Oops!", Doctor Join Date: Nov 2003 Location: Houston, TX Posts: 677	Yeah, I'll play with that flap a bit while I'm waiting for the engine to warm up tomorrow morning. I can't think of any reason other than those flaps that it shouldn't be roasting me out of there like it did last winter. Once I get that fixed, I'll turn my attention to the screaming/growling blower motor and the windshield washer that only seems to want to spit instead of spray. Why does it wait until 0 degrees to pull these stunts? __________________ 'Mutt 1968 CST LWB: R.I.P. 1967 Chevelle: TPI 454 beast 1967 C10 SWB: Claimed when Bumpster didn't put it on his list

01-17-2005, 12:12 AM	#10
useRc10 Registered User Join Date: Feb 2001 Location: Mechanicsville, VA, 23111 Posts: 1,138	70 shorty- check the bulbs before you go pulling anything else apart...i found in mine that they are like x-mas lights...one burns out and they all go __________________ -'02 Chevy Avalanche, 5.3L, 4x4... needing a small lift and bigger tires -'72 Chevy C-10(350, bored 60 over)dual flowmasters, 3 on the tree -'85 K5 Blazer,305 NO MORE...350 is in,2" lift,33" Mickey Thompson Baja Claw Radials -dads '70 burb (red, 5-7 drop, 350...) www.geocities.com/userc10/truckhome.html AIM: Auntjoedadda

01-17-2005, 12:57 AM	#11
72 Cheyenne K20 Registered User Join Date: Feb 2003 Location: Staunton, Virginia Posts: 554	I have a 70 w/air and had the same prob with the heat. There's a valve on the pass side inner fender that only A/C truck have that was gummed up and not letting an circulation thru. I replaced the valve and have more heat than I can stand.

01-17-2005, 01:05 AM	#12
orange72 Registered User Join Date: Sep 2000 Location: huntington,texas,united states Posts: 399	lol i thought i was the only one with that screaming motor...you can hear that thing a mile away. __________________ 1972 chevy long bed. Currently under construction!! Bagged, 383/700r4.

01-17-2005, 01:11 AM	#13
shuttermutt Don't say "Oops!", Doctor Join Date: Nov 2003 Location: Houston, TX Posts: 677	Valve on the passenger's side inner fender, eh? I'll look again, but that doesn't sound familiar. Was it a vac operated contraption, perhaps? Any idea what it's called or what it does? Oh, and you're certainly not the only one with a screamer, orange72. Mine has a personality. It's either dead quiet (75% of the time), growling (15% of the time) or screaming like a banshee getting its butt hairs ripped out (10% of the time). I've heard it's a bear to replace that motor so I'll probably wait until it fails altogether. __________________ 'Mutt 1968 CST LWB: R.I.P. 1967 Chevelle: TPI 454 beast 1967 C10 SWB: Claimed when Bumpster didn't put it on his list

01-17-2005, 01:17 AM	#14
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	The blower motor isn't hard to remove, but you DO have to remove the hood hinge. After that it's a matter of a few bolts. To prolong the blower motor's life, drill a small hole in teh center of the metal 'hub' portion, and spray some graphite in there, then a dab of black RTV to cover the hole. I did this on the 'ole GMC the day I bought it, and to this day it works fine...well, at least it did in Oct when i got rid of it. That valve on the inner fender is a vac operated valve. it turns the coolant flow off all together so when you turn on the A/C there is no heat in the heater core.

01-17-2005, 01:21 AM	#15
72 Cheyenne K20 Registered User Join Date: Feb 2003 Location: Staunton, Virginia Posts: 554	the valve is vac controled. Looks like the book is calling it a shut-off valve. If I can get a pic I will post it.



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01-17-2005, 01:59 AM	#16
wanted Registered User Join Date: May 2003 Location: duluth, mn Posts: 63	Mine would only blow warm air. I idled the truck with radiator cap off for awhile to get the air out and now the heater is baking hot.

01-17-2005, 03:57 AM	#17
Americanrider Registered User Join Date: Dec 2004 Location: NW, WA. Posts: 1,421	Holes in firewall Once had an old CJ5 Jeep with a firewall that looked like swiss cheese. Got mad one day and plugged them all with plain ol' bathtub caulking, (the only thing I had at the time) it's easy to remove if I wanted to run another wire and no more engine fumes. You can paint it over too!

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