• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

Fixing the 1998 HMMWV

mrandig

Active member
85
115
33
Location
Houston, TX
Heater / Defroster Duct Removal.

Based on the abject failures of earlier this week and last, I decided to focus less on taking pictures. Why bother if it's not going to work out, am I right?

That being said, one thing led to another, and now all of the heater and defroster ductwork is being replaced. This is a good thing, as the cabin would just fill up with dust (sand) anytime either were turned on.

Any pictures I have then are post-mortem, rather than in-process, but I'll explain the best I can.


The first step is to remove the access cover on the passenger side. The fasteners don't quite match what's shown in the manuals, but mine was two bolts at the top right, and one screw at the lower left.
20250418-084512-004.jpg

Once the cover is removed, you'll have full access to the entire unit, including both duct assemblies and all of the flex ducts. Obviously, I took this picture after the flex ducts were removed.

The bug sprayer is filled with soapy water, as I like to clean as I go.
20250418-084519-005.jpg

The right-hand defroster duct and nozzle are pretty easy going. Just unscrew the lower clamp and wiggle the nozzle out of its channel.
20250418-084546-006.jpg

The large heater duct which bridges across the doghouse will need to be removed. For me, this needed to be replaced anyways. Mine didn't have any clamps, so it was just a slip-on/slip-off situation.
20250418-084606-008.jpg

Once the heater duct is out of the way, there is a body panel and a retaining strip that will need to be removed from under the windshield frame. There's a total of eight screws inside the cabin, and three bolts in the engine compartment.
20250418-084620-009.jpg

Once the body panel is removed, there will be some insulation strips that will also need to removed. In my case, they just fell out, so I didn't need to do much. The question is, how we will put this back together once the time comes to reinstall.

My money is on double sided tape, but we'll see.
20250418-084641-011.jpg.

The left-hand duct and nozzle are almost more trouble than it's worth. From the doghouse side, pulling on the duct will get you a big handful of shredded duct work, but removal of the nozzle requires access from behind the dash.
20250418-084627-010.jpg

You're going to need to drop the steering column for this part. Also, I had already managed to break both my turn signal lever and air restriction gauge during my earlier exploits, so be careful.
20250418-084712-013.jpg

Once the steering column is dropped, you'll be able to access the retaining pin that holds in the left nozzle. It's still pretty tight to get to, but not impossible.
20250418-083636-001.jpg

I ended up using an automotive trim tool and was able to get the retaining pin out, in mostly useable condition, for re-installation.
20250418-084659-012.jpg

Retaining pin removed.

Considering how over-done, over-thought, and over-priced everything else is, it's like they got close to the end of building this truck and just said screw it. "We'll just use the interior trim pieces from a Chevy Cruze".
20250418-083731-002.jpg

Left duct finally removed. It's a funny process getting this nozzle out, as you have to turn, twist, push, and then pull a few times, but eventually it does come out. Supposedly it should be turned clockwise to install, counterclockwise to remove. Supposedly.
20250418-084101-003.jpg

Once everything is cleaned up and organized, we'll start putting in the new parts; hopefully later today. More updates to follow...
20250418-084556-007.jpg
 
Last edited:

mrandig

Active member
85
115
33
Location
Houston, TX
None of this was on my original to-do list.

Actually, it looks worse than it is. With some luck and a little bit of time, this should be all back together by tomorrow.

A few updates to follow shortly...
20250418-124301-016.jpg
 

mrandig

Active member
85
115
33
Location
Houston, TX
Replaced the fuel gauge with a Faria one this evening. This was absolutely one of the issues that was causing problems.

Notice that it's pegged to the far right with power and ground connected, but without the sending unit attached. This is exactly what this gauge should be doing.

It's frustrating however that this gauge is scratched right from the box, but at least it's only cosmetic; we'll deal with that next week.
20250418-202742-017.jpg

The new gauge seems to be reading pretty high, but the tank looked very full also. I'm not sure if this reading is correct, but at least now, if there is an issue, I can focus solely on the fuel sender.
20250418-202940-018.jpg

While I was changing out the fuel gauge, I also replaced the gaskets on the dash lights. I didn't take a picture here, but it definitely makes a difference with the gauge illumination.
20250418-203332-019.jpg

All done with the dash and gauges. We'll get this back in for good once the flex ducts are installed tomorrow.
20250418-203419-020.jpg
 
Last edited:

mrandig

Active member
85
115
33
Location
Houston, TX
For my last item this evening, I want to knock out the brake warning indicator that has been giving me problems. Actually, it hasn't been giving me anything, which is why I need to change it.

Brake warning indicator.

Here's my problem-child. I already removed the air restriction indictor so I could gain access to the lamp wiring.
20250418-203809-022.jpg

Warning light disconnected.

Disconnecting the lamp and testing it is a little tricky, as there's not really room for two hands, but it's possible. Looking for a full 24v on this circuit with the parking brake engaged. Alternately, instead of engaging the parking brake, I could've grounded the switch at the proportioning valve, with the same result.
20250418-204514-023.jpg

Results are in, and they are correct. We've got 24v when the parking brake is engaged, 0v when it's not.

There's nothing wrong here except for a bad light.
20250418-204519-024.jpg

Light Replacement.

This was another piece that was tricky to replace but worked out in the end. The space behind this lamp is really narrow, and it can't just be shoved up and into place.

I ended up sliding the lamp into place from the open dash panel (not shown). There's a channel behind the dash face, and the light can just be slide sideways right-to-left until it's in the correct location. It's just two self-tapping screws that hold it in place.
20250418-211515-025.jpg

Success!
 
Last edited:

mrandig

Active member
85
115
33
Location
Houston, TX
This weekend is going to be lit. As my youngsters would say...

It's Easter weekend and I've got a box of cleaner and radiator paint.
20250418-123108-014.jpg

20250418-123117-015.jpg
They even gave me coupons. I can get ground beef for life, discounts on deodorant and ED pills. Interesting choice of combinations, but I guess I can see how at least two of those go together.

Once the flex ducts are replaced and the interior has been re-installed, we'll come back to this.
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks