Fuel /electical problem

[zanman]

I bought a M884 and wanted to use as a plow truck.I ended up hooking up a Fisher hydro plow up to it.When I bought the truck none of the gages worked and still do not, by the way had a 12v battery in it.Anyway the problems I have is 1) when I turn ther lights on there is a clicking in the dash that will dim then shut lights off and 2) I cannot put gas in it because it will back up and pour out the fill tub.It is vented3) gages do not work .Is there something i need to investigate regarding t hese problems.ZANMAN

 

[M725]

I want to welcome you to the M880 and all the neat problems that come with it . I 4 of them , I can only fill them with gas at a slow rate. I have had the tank out of 2 of them. I found nothing they just fill slowly. With the gages you need to start at the fuse box and go from there. Sorry I can't be more help.

 

[M725]

I just did some checking, you got me wondering again about the slow fill of gas. I was just told the cause is the 90 degree on top of the tank.

 

[M880 GC]

Zanman,

I'm new at this also, just got my M880. I sincerly suggest that you somehow get a look at the ammeter connections on the instrument panel. If you see corrosion and discoloration, that's resistance at these terminals creating heat and it is the power connection for the trucks electrical system. I am finishing up having pulled the entire dash wiring harness out and looking for and repairing any bad connections that I could find and bypassing the ammeter. See the post further down in M880 forum about wiring around it. For the clicking, check your dash near the fuse box for a headlight relay. When I started hooking mine up, it was clicking also, looks like I'm going to re-wire around it. You may also have a second relay (see TM in resources) located near the headlight switch. The headlight switch on mine was also a problem area. According to my local dealer, the plastic insulator and special locking spade connections are no longer available. In the TM there is a section specifically for the blackout switch wiring.

Good luck.

 

[N1265]

Just so you know....

The clicking in the dash is usually :

1 ) parking lamp relay, This is bolted in the dash next to the fuse panel. It is easy to get to if removing the plastic glove box liner. It has three wires going to it and only effects the " running lights " ( wich include the tail lights ) head and break lights are not effected by this relay. The clicking noise is normal for the stock relay.

2) The military 3 lever switch has an internal relay that will make a clicking noise when it trips, when it does you loose everything that has a light bulb in it. I have never known them to go dim, then out. Just a big click and then no lights.

There is a third relay under the dash ( if your truck has blackout lights ) that is suppose to be mounted by the emergency brake relese lever. It only effects the horn.

I just replaced my relays with BOSH ISO relays. you can get them at any car stereo instilation place for $10. ea. and work great.

Keep us posted on your progress, any other questions just ask. There are a couple of us here that just went threw similar problems.

 

[N1265]

As far as the gages.....

on the instrument cluster there is a silver box that plugs into the back, If it is bad or missing none of your gages will work.
( except for the ALT gage, If it has not been re wired from a PO )

I will try to post a lint to another forum that explains what I am talking about.

 

[N1265]

Here is a link that will show the relays I am taking about,

http://www.powerwagonadvertiser.com/forums/showthread.php?t=9028

 

[N1265]

Also with the dimming light, Be sure to check all of the grounds...

 

[M880 GC]

N1265,

Thanks for the additional information about the relays. I have the one by the fuse box, but not the one by the parking brake. I found them in the TM, but didn't come up with an explanation of the circuitry. For right now, I reverted back to parking lights and headlights being powered by the normal headlight switch.

Merry Christmas.

 

[N1265]

The one By the fuse box is a Mopar part that was put on at dodge, they can also be found on some of the civilian trucks.
( I think the ones that came with a towing package, to help protect that circuit with the extra lights on the trailers)

The one by the brake release ( horn relay ) was part of the blackout light kit that was usually installed at the depot or unit level. Your truck might not have had the Blackout lights installed, or if it was, PVT Smuck might have mounted it in a difrent location.So it is no big deal if it is not there.

Also, Just so you know, these relays need to be grounded threw their case. if having trouble with a circuit that they control. you might want to make sure they are grounded good where they mount to the dash
( by sanding any rust or paint off between the case and the dash )

Come to think of it, you might want to check to see if your Dash itself is getting a good ground, This might also explain why your gages do not work, because they are also grounded threw the metal portion of the dash....

Also, I Just re read your first post, the electrical system on these these trucks are 12 volt so a 12v battery is correct.

good luck, Merry Christmas and keep us posted !

 

[zanman]

Thanks for the great replys I will be looking into the dashboard issue Monday,holiday has me busy I also have a third problem, when slowing the truck to a stop the truck will stall out.It is definitely a carb issue I will clean it out initially after this I will need assistance.I am not familiar with carb it is 4 barrell Holly 360.Stay tuned Dave.

 

[M880 GC]

N1265,

Good additional information about the relays and other electrical gremlins. I will put a status update on my truck's progress under M880, Begining. Got some good news to report.

 

[Bob H]

Fuel fill backups are generally due to a clogged vent hose, mudwasps love to build in them.