85 K10 Stepside, Not charging?

[KY..Rob]

Hey Guy's, I have a problem with my 85 GMC K1500 swb stepside. The truck has a swapped in 355 with a 4 speed (Sm465) with I believe a 208 T-case. The truck was born a C1500 with the 305 and Automatic Trans. I bought the truck a couple days ago in Indiana, I live in Kentucky.

I bought the truck under the impression it was a true K1500 but found out otherwise when I checked the VIN. The guy told me it used to be an Auto but not a C1500.

But it is what I have been looking for and the truck is in great shape Body wise and frame are all still solid. sorry for the long rambling.

The problem I'm having is the charging system? I have replaced the Battery, Alternator, starter. and belts. I'm thinking it's a short but I can't find it. Their was a lot of aftermarket stuff hooked up in the truck which I have been tracking down and taking out. (Big ole monster Tach) and aftermarket gauges and toggle switches. and old radio and speaker wires.

I'm trying to get back to using the factory gauges (Is this still Possible) and I'm still not sure what the ECM controlls now? if anything at all. I'm having trouble following the wiring diagrams in my Haynes manual, I'm not electrically inclined..LOL


Sorry for the long post, any and all help will be greatly appreciated..Pics to follow very soon.

Thanks,

Rob..

[VileZambonie]

Do you have the field wire hooked up to anything? What about the gauge is it connected?

[Captkaos]

Maybe I am missing something but an 85 won't have an ECM.  Getting it to work with the factory gauges is possible as long as the connector is there and you have the cluster.

[jaredts]

Food for thought:  When I bought my truck a few months ago it had a new alternator on it but had intermittent charging issues.  No visible wiring problems but when I took the negative battery clamp off it was caked with corrosion all around the cable.  I cleaned it up and put a new clamp on (also added a missing ground wire to the cab).  It now charges perfectly.  I've had similar problems in the past.  Closely check battery clamps and ground connections, it could be that easy.

[KY..Rob]

Thanks Vile, and Capt. I have tracked down all the red wires starting at the battery, their are 3 wires going to the starters main lug and one wire (looks Brown) going to the "S" post on the starter solenoid. Big ground wire off battery going to the alternator hanging bracket. Up on the firewall there is a lug with 2 big red wires going into it, and one of them comes back around the intake and goes to the alternator and then the red and white pigtail that plugs into the top of the alternator.

On the inside I have taken apart the whole cab. I can't find any of the wires that would plug back into the instrument cluster. I do have the fuel gauge and speedo, and they do work. My gauge cluster is all gauges and no dummy lights. I can't find anything in there that looks like it will plug into the back of the clusters gauges (Volt Meter) and (Oil Preasure).

I say ECM because the fuse box has 3-4 openings in it marked ECM. But there is no fuses in them. And under the dash above the glove box is a yellow box with a black top, it measures about 8" long and 6" wide and 2" tall? Maybe this was the spark controll system, I thinks 85 was the first year they used this and Hydro clutches.

The interior lighting has been whacked on as well, but I will tackle that as soon as I get this beast running. I tried to drive it back from Indiana Saturday and thats when she went down hill. The big monster tach just started going haywire and spinning the lights shut down the wipers quit working. no brake lights. Turn on the head lights and then you would have no brake lights..LOL..


Vile, you said in your first post a Field wire? do you mean like a hot wire or a wire from the ignition?

Thanks,

Rob..

[KY..Rob]

Jaredts, I will get under the cab and look around for ground wires, there are some ground wires attached on the inside of the cab. I have cleaned out all the wires I'm comfortable with taking loose and feel they are not part of the original system. Over the years I guess some kids have owned this truck and have wired all kinds of stuff into it and taken loose a bunch of stuff. I did find the plug to the clock..LOL..I just need to find a fuse to plug it into and ground it. My big concern is the charging and the "Temp and Oil gauges.

Rob..

[KY..Rob]

The battery cables are new, and side post. I took the alternator to auto zone and had it tested, the guy it says it is working fine. I do notice a little slop in the belt I'm going to see if I can get it tightened up a little more.

Rob..

[Captkaos]

If your fuel gauge is working the plug to the cluster is already plugged in.  If your other gauges dont work, they I would check your sending units to see if they are plugged in.

If you turn on the interior light, you have something blowing either a fuse or a bulb.  My pickup did this and it ended up being the previous owner put in a radio and tied the illumination light into the factory wiring, but cut the others and you had 2 powered wires connected together

[KY..Rob]

[KY..Rob]

Ok so it's the IMG code on Photobucket.

Here are some pics of the inside as she sits right now, maybe we can Identify some of the components in here..Capt..Yes the cluster was plugged in it has on big terminal in the middle. so I guess with the printed board I just need to track down the sending units wires? I noticed the temp gauge has a small pin in it, on the cluster. Could i take the temp metal wire from the aftermarket unit and hook to it?

This thing here was bolted to the driver side inner fender. I dont know what it is? It had a couple small red wires hooked to the bottom of it and a ground wire up to the front





I think this is the alarm and signal horns and warning bells

[KY..Rob]

This the thing I called the ECM? not sure what it is, but it's buried up in the dash behind all the Duct work.

[VileZambonie]

Where is the white and red wire on the alternator going to? It looks like the white wire is cut and touching your valve cover?

[Captkaos]

I noticed the temp gauge has a small pin in it, on the cluster. Could i take the temp metal wire from the aftermarket unit and hook to it?

I wouldn't.

The thing in the glove box is the ESC.

[Josh454]

What exactly is the issue you are having?  Is the truck not charging (stalling with a dead battery) or is the volt gauge not reading?

[KY..Rob]

The White wire is spliced to a Brown wire, and travels back in the wire loom and up around the fire wall, and ties to a block next to the brake booster. In one of the pics up top, you can see a group of white wires on the drivers side. those are interior lights that have been cut loose. The dome light is cut also and is laying behind the seat, it's orange/white and white.

I did find one interesting wire though. A Blue wire coming from the brake switch, with it was a brown wire, the brown wire runs down the steering along the fire wall and ties into the fuse box with a connector. The Blue wire travels with it, but turns and goes out the fire wall with a rubber grommet attached to it it was cut on the other side. I hooked the battery back up and it was a hot wire? I unplugged the brown one from the fuse box and they both are dead now and the brake lights messed up.

I have the driver side brake light. Turn on the head lights or parking lights and the driver side dies and the passenger side works..Go Figure..LOL..With a little help from you guy's I will get her going again..

Looking for any and all input.

Rob..