M886 Commo Truck Build

[m38inmaine]

Picked up this M886 from another SS member yesterday, plan is to build it into a commo truck for local ARES events and military shows.

Started today on cleaning up and removing some old parts. Trailer hitch was quite low to the ground so I removed it. The exhaust needs to be replaced and the majority of it also removed. Next project was to move the folding step from the center to the RH side, this way I can get in from the rear having to open only one door. I was able to use the original hardware and it was a simple project. The RH litter support was already removed leaving room for the step. I would have removed it any way as the radio rack will mount over the wheel well area.

Also on the list to do is replace the grill and the roof top needs attention as well as new paint and a lot of small electrical items to run down. I need to track down a LH upper litter and brackets so I can sleep two.

 

[Amer-team]

That is a really a pretty straight looking M886. Nice idea on the step. Mine still has all the stuff back there so that is not an option. You might look at cutting the ends off the hitch you have and welding it inside the frame rails. That gets it up and out of the way. And you will still be able to pull a small trailer with it. Some of the guys told me that they didn't have a hitch so that they wouldn't pull something with them. Also the step would not work hitched to something.

 

[bikeman]

Looks like a 76 grill on a 77 chassis.

I've found success with parts through the various classic Dodge pickup pages on Facebook.

 

[Amer-team]

Is that a 77 truck? If so someone will be very happy to have that 76 grill. It looks very straight. Good thing about the M880's is that you can go to your local parts store and still get most of the parts you need.

 

[bikeman]

It looks like a 77, based on the fact there's no space below the headlights for turn signals... but since I haven't actually messed with one in person I could be wrong.

 

[m38inmaine]

Thank you for the replies, appreciate the support. It is a 77 shows date of delivery 4-77, the grill seems to be cobbled up from various parts, ill post up some pictures of it up close. I also have a M882, when I got it the blackout light kit was installed, I started having problems with the lighting so I removed the kit/harness. So today I removed the harness on the 886, for some reason the wiring on the two trucks is a bit different. I am going to print the schematic and see whats going on. On the 882 it was pretty much plug and play, not so on the 886. Ill get some pictures up showing the difference. Stumped right now on the red and green wire missing from the light switch. The harness branch going to the light switch has the green on the 882 but not on the 886. The red wire on the 882 comes over from the top of the instrument panel, no red that I can find on the 886. Also the 882 has a circuit breaker between the two flashers in the fuse box with some extra wiring going to it, the 886 does not have the circuit breaker or wiring for it. I'll report back tomorrow once I have had a chance to look over the schematics.

 

[Amer-team]

If there is something you need, if you take a picture, maybe I could post a picture of mine to help out. It might lead you on the right wire direction.

 

[bikeman]

Ditto. I have an unmolested 77 M880 and a Fire-Department bubba'd one.

 

[m38inmaine]

I printed off the schematics and found a few interesting things. I don't see any M886 specific wiring diagram like they have for the M1010, I also can't find one for the separate fuse panel the M886 has below the dash or a picture of the fuse panel which I could swear I had seen one which labeled which fuse goes to what item. There is a separate schematic for the parking light circuit which is how my M882 is wired with the extra circuit breaker between the flashers, however the main schematic does not show this circuit and shows the parking lights wired direct with no relay or breaker, whether the parking light relay was omitted by accident or added on I don't know. This is where I see the red wire on the light switch on the M882 which goes over to a relay mounted to the right of the fuse box. I wonder if this parking light relay/breaker circuit was an add on or kit? According to the original schematic I should have a Brown(red on the 882)which goes to the parking lights directly through the bulk head connector and a dark green going to the fuse box. I did locate both of those colors going in to a 3 prong plug, one slot empty, which is floating un hooked, I also don't see what may have mated to this plug. When I get home I am going to trace the green and brown to see if those on the plug are the two I am missing from the light switch. Would be curious if your trucks have the breaker in the fuse box. (The manual does show a crude wiring routing for the 886 box and wire colors for the extra indicator lights for the 886 dash).

Also interesting is in the -20 they show two schematics for the blackout lighting kit wiring, it shows one with a ambulance specific fuse panel location and shows no relay/breaker in the main fuse panel, perhaps the 886 does not have the breaker/relay for the parking lights. Also on the same two blackout wiring schematics they show original and the added harness wiring and relays, on the 886 it shows there are two added relays, on the other it shows they only added one relay for the kit. This would lead me to believe that the floating plug I found, with the correct colors, was added to the two original wires(green/brown) going to the light switch so they could be plugged into the added relay. I am also thinking where the ambulance has no trailer connection an additional parking light relay/breaker was not needed(as shipped from factory) as it had no additional load to carry I/E trailer lights. In order to have a one size fits all blackout harness they just added the additional relay in the kit for 886 applications. When I trace it out will be the proof to my theory.

 

[Super Warrantman]

Thank you for the replies, appreciate the support. It is a 77 shows date of delivery 4-77, the grill seems to be cobbled up from various parts, ill post up some pictures of it up close. I also have a M882, when I got it the blackout light kit was installed, I started having problems with the lighting so I removed the kit/harness. So today I removed the harness on the 886, for some reason the wiring on the two trucks is a bit different. I am going to print the schematic and see whats going on. On the 882 it was pretty much plug and play, not so on the 886. Ill get some pictures up showing the difference. Stumped right now on the red and green wire missing from the light switch. The harness branch going to the light switch has the green on the 882 but not on the 886. The red wire on the 882 comes over from the top of the instrument panel, no red that I can find on the 886. Also the 882 has a circuit breaker between the two flashers in the fuse box with some extra wiring going to it, the 886 does not have the circuit breaker or wiring for it. I'll report back tomorrow once I have had a chance to look over the schematics.

For what it's worth, there were 1976 and 77 models. The parts TM has a note of some items that were only used on the 1976 models. Tom Zat sold a few 1976 M880s. Here's a picture of one he had on his web site. I don't think he has any more though. I bought my 1977 model from him in 2011.

 

[m38inmaine]

Yes the manual does point out a few items specific to build date, when it comes to the electrical it would seem you are left on your own to figure it out. Thank you for the input.

 

[combat32]

You got a shiny bumper

 

[m38inmaine]

Yes she is shiny ! It looks like the hood and at least the passenger fender are from a civvy Dodge as is the bumper. As you can see the grill was cobbled up from a pre 77 truck, also has a inside hood release. The radiator support is rotted beyond repair, even the bolts holding it to the frame are gone. The inner fenders are about perfect so it could be worse. Looks like I need to find a parts truck for some front end parts and wiring. Temporarily put on my grill from the M882 just for a photo op.

The wiring is fixed and back to pre blackout install condition, my theory on the missing wires was correct. I do have a picture request, would like a couple of pictures of how/where the ambulance fuse panel is mounted and if it is labeled.

 

[m38inmaine]

The seat cushion for the folding step was broken free from the step, the t nuts had let go and the plywood was tender. Cut a new piece of plywood, new t nuts and 10-24 flat head screws finished the install. When I got the truck the carburetor was off due to a sticking float. The inside was full of white corrosion and dirt, procured a NOS rebuild kit for $10 and dove in. These carburetors are pretty simple inside, cleaning takes time but worth the effort. All back on and ready for the first start. Also noticed when the fuel pump was replaced no fuel filter was installed, just a straight hose, so I installed the correct in line filter. Next on the list is to upgrade to a GM style HEI ignition module and GM one wire 100A alternator.

 

[m38inmaine]

Today I started the GM HEI ignition conversion, this worked great on my M882 so I decided to install it on the M886 as well. I ordered a Powermaster 100A one wire alternator so I eliminated the voltage regulator. I traced out the shape of the regulator on a piece of 1/4" aluminum for a heat sink for the HEI module. All I have left to do is finish a couple of wire connections and it will be done. I knew when I bought the truck the roof skin would need to be replaced, I can see on the drivers side on the back wall where water has been coming in. Knowing I would have to take the wall panel off to check for water damage I figured I would take the box out now. Not much holding it in, they did a poor job at the body co., better for me I guess. I set the radio rack in place and it is going to work just fine, won't secure it until the box is finished.

 

[N1265]

GM ALT and HEI conversion is a good upgrade...

 

[m38inmaine]

Thank you, well not quite a GM alternator but an upgraded 95A one wire by Powermaster, a direct fit, also eliminates the voltage regulator. Seems like it's going to be a one step forward 4 steps back type of build. While replacing the exhaust I found the LH manifold was damaged at the sealing surface and the head pipe mating surface was paper thin. So had to order up a new manifold and head pipe along with the other exhaust parts. Also found a kind person snapped off one of the studs on the EGR block off plate, I am pretty sure I could hear exhaust escaping here and the blown gasket provided the proof. Spent an hour or more drilling and tapping the stud, of course the newly installed carburetor had to come back off for access. Another gift was a rotten heater core, noticed that it was bypassed, now I know why, removed the entire heater box as it was quite nasty inside so might as well clean and service it now. Spent a good amount of time sanding the rear door interior and removing paint from the window gaskets, lots more fun.

 

[Jericho]

Mark. I just wish I had your energy !!! Good job as usual. I would expect nothing less from you. Love your build threads. Have to figure out you financing theory !!

 

[m38inmaine]

Just try and work on it each day, might not be a lot every day but it adds up. Last couple days has been one of those not so fun but must do projects. Pulled the interior panels out of the box, it was a mess in the walls, spared the pictures of the nasty mess. The roof panel for the most part looks pretty good, they welded 4 sheets to make up the roof, the rear section, about 19x75 is what needs to be replaced. I plan on deleting the roof vents so this will also eliminate the vent holes.

 

[m38inmaine]

Super hot here today but a lot accomplished on the 886. Correct gasket for the manifold finally showed up(mis sorted by ups)so I could finish the manifold install. It seems a non emission type is not available so I had to make a block off plate for one end, the manifold came with the other two necessary plugs. I have all the new exhaust in place just need to tighten it all up. Replaced the firewall side of the heater box and installed the new blower motor and fan. Also installed tow bar adapters up front just in case. Next on the list is to sandblast and prime in the box, way too hot to suit up today. Some exhaust part numbers, Y pipe 40405, tail pipe 45656, tail ext. 42499, manifold gasket set MS90460, LH manifold 674-233, muffler 18142. The pipe from the y pipe to the muffler is discontinued, I repaired mine by welding new pieces on each end or you could have one made at a shop. You will also need 2 1/4 and 2 1/2 clamps and my need a couple of universal hangers depending on the condition of them.