[cao88c]

Hey guys, a few months ago, I bought a 99 'burb for my wife. Truck is awesome, and no complaints.

The only thing is that the heater does not work. (no hot air). Hot can I fix this. I was originally from south fla., so I never had a use for a heater, but where I'm living now, we NEED the heater to work.

Another question: what spark plugs are you guys using on your trucks. I have older chevy trucks and always use champion truckplugs with no problem. Just wanted to know if those will work fine with the 'burb (btw its a 350 engine).

The last thing that I wanted to know is: will 31x10.5r15 tires fit on this truck with the stock setup? Gotta change the tires and I'm getting a great deal on 31's. Just don't want them to rub. Its a 1999 2wd.

All info is greatly appreciated!!!

 

[MrShorty]

I don't know what's different on a C1500, but I run 265/75R16's and 32x11.50R15's on my '98 K1500 without any issues. Unless the C1500 is a lot different, I expect 31's should fit fine.

Most people who have any opinion on spark plugs say to stick with the AC Delco's. I've got Autolites in mine.

Can you be more specific on the problem with the heater? When you say it "doesn't work" is it a case of not blowing any air (probably a problem with the blower) or a case of it blows plenty of air, but the air isn't hot?
For the former case, inspect the wiring to the switches and blowers. For the latter case, do you have coolant flow through the heater core? When was the last coolant flush? Does it have a rear heat/AC unit? If so, does the rear unit blow hot air?

 

[cao88c]

Hey, thanks for the response. The blower works, just when its on heat, no hot air comes out, just regular air. The rear does the same thing. Where is the heater core located?

 

[MrShorty]

What does the engine temp gauge read? Is the engine coming up to operating temperature?

If you look under the hood, passenger side of the engine, below the air filter housing, and the AC accumulator, you should see a part with 6 coolant hoses coming off of it. 2 hoses go into the firewall (that's where the heater core is), 2 hoses follow the frame rail to the rear heater core, and to go to the engine. That part is the heater control valve, and regulates the flow of coolant to the heater cores.

The usual 1st "quick and dirty" check is to get the engine hot, then feel those hoses. If the hoses are all equally hot, then there's a good chance you have good coolant flow through the heater cores (so the problem maybe lies in a blend door or other part of the HVAC system). If the hoses going to the heater cores are cold, but the ones going to the engine are hot, that suggests that the control valve isn't opening to allow coolant to the cores. If one hose to a heater core is hot and the other is cold, that suggests that flow through that core is restricted.

 

[cao88c]

Ok, the temp gauge stays right in the middle between 100 and 210. I noiced where the heater hoses are located, and they are blocked off by a crimped piece of hose on both ends.

I figue that the heater core must have been leaking and instead of fixing it the PO must have just bypassed it.

Now, to get to the heater core, do i have to take out the dash board, I was looking for it, but I couldn't find it.

Also, is there some sort of technical write-up on how to do this (I am a member of jeepforum, and they have tons of technical write-ups that make the job a heck of a lot easier). If not, I'll be more than happy to do one and post it with pics.:smile:

 

[MrShorty]

Haynes describes a fairly involved procedure requiring partial dissassembly of the dash.

 

[cao88c]

Ok, thanks! I guess that I have something to do next weekend!

 

[caprice88]

I got on my 96 c1500 31x10.5x15 tires with no problems. I think the 99 is pretty much the same.