88 r2500 CC, 6.5 retro, 12v lighting gone if running

[Joesince83]

Hello, ive lurked for years but finally created account and am in.

I have a 88 crew cab 2wd Oregon Navy Guard truck. Its been swapped to 6.5 by the govt I was told. Ive been driving it and enjoying it quite a bit. About 6 months ago it stalled at a light. I checked batteries, good. Went thru everything I could on side of the road and am not exactly sure what I did but I got it started and home. It will only start with the black push button compressed. It will run fine, as long as I don't turn on the lights, hit reverse, sometimes the pushing the brake pedal will kill it.

Ive been thru the starter relay, horn assembly and relay, as well as many others. I believe it has something to do with the rubber button switch under the left side of the steering column, which runs to the starter relay and glow plug controller.

Its the oddest thing to me so far, this truck is an 88, 3/4 ton 2wd crew cab, so it does not have the typical blackout set up. If i remember correctly though, before this issue occurred, this button functioned as a blackout on/off. Now it functions as, it must be pressed in order to have any power to start, lighting, blinkers, etc. once the button is released, the truck operates and drives fine, as long as i do not turn on any lighting, hit reverse, blinkers, etc.

Any leads, suggestions, info would be greatly appreciated as I am ready to drive it semi daily again.

 

[richingalveston]

like many trucks, yours has been modified, in stock form there is no black button. you don't have a stock wiring anymore and you will need to post lots of pictures for anyone here to be able to help.

Most likely you have an electrical problem that is causing the Injection pump shutoff solenoid to loose power.

The pink/red wire on the top of the motor is what goes to the injection pump solenoid. If it dies on you and wont start, try running a jumper wire from a 12 volt source (should be front battery + terminal) directly to the IP. then try to start truck. you will have to remove the wire to kill the engine.

Good luck, jacked up wiring can take some time to resolve.

Rich

 

[Joesince83]

Thank you for the reply sir. After further thought, I believe this rubber booted switch might be a manual glow plug switch.

If I hold it in, I get all lighting, glow plugs light comes on, then out, then I can start and drive normally, with or without holding the switch in. However, if I release switch , if I turn on any lighting will cause truck to die and lose Elec power.

Here is some pics

https://ibb.co/b28L0a
https://ibb.co/d2jFYv
https://ibb.co/eSO9tv
https://ibb.co/fs9FYv
https://ibb.co/jtuhDv
https://ibb.co/mLGJmF
https://ibb.co/kpDL0a

 

[Joesince83]

I'm getting no power to anything by simply turning ignition on, I must hold the switch in to get initial power to ignition, start, lights, anything. Once started though, it's drives fine as long as I do not use any lighting , and all dash lighting , brake lighting, etc is non functional, unless I hold the switch in.

 

[richingalveston]

It looks like a civy 6.5 and not a cucv.
it appears you have two glow plug relays, old style and a st85 or the other relay works the starter or something else I cannot tell.

the terminal block pick appears to be missing the 12V feed from the front battery (img 1721). the blank screw on the block should have a large wire from the front battery.
look at the cucv wiring diagrams and compare to what you have.

good luck.
rich

 

[Joesince83]

Yes I think I've figured out it's originally a civi 6.2 built for Navy Guard, retro'd with a 6.5 no egr from 1994. Truck runs great, not a lick of rust anywhere but battery trays, and very unique awesome, couple pics below. I used to have a silver Air Force Guard m1008, and was looking for another when I came across this about a year ago. I was daily driving it for a few months, until this all started up.

At this point I'll be looking into that 12v to block you mentioned, but also the temp switch, or even the ignition switch. If ignition switch, power running backwards thru manual glow plug set up to power ignition. Will report back.

https://ibb.co/fLyCwF
https://ibb.co/h3fEAa

 

[gimpyrobb]

No pics of the motor so we can't tell what IP is in it. Is it a mechanical IP?

 

[Joesince83]

I'll pull it out asap get lots more good pics, there are a few in the links above I took real quick but it was in the back of shop with poor lighting. My guess is its a mechanical 94 IP. I have a spare if i could find it from a early 90's civi truck. Ive only had a 6.2 stock cucv and a 98 6.5 van, which sucked btw.

Truck is a single alternator, two 12v in series. I haven't been underneath it yet because new shop doesn't have lift and this thing nearly sits on the ground. They have added a late model bumper and wired it for modern trailer plug and i think it may be terminated in my problem area, so gonna take a look at that as well. Also gonna go back thru battery terminals again, last time i was on side of road. I have access to starter alternator rebuild shop, so prob end up going through those as well in time. Cannot wait to get it back on the road semi daily. It's definitely more of a custom, but really seems to be all stock so far but the drop, rear bumper, walmart radio, trailer brake box, and the black button.

 

[Joesince83]

I finally got a decent day to pull it out and go back through it again. All batteries, cables, connections good and clean. This is wired civi, so the junction block is wired correctly the best I can tell from schematics. Everything appears to be stock, other than the added manual glow plug set up.

I found it the culprit though, and **** it feels good to have this thing back on the road daily.

All of the power runs through the starter solenoid. There was a bad crimp on the power feed from starter solenoid up to the junction block on the firewall. That's it. The beauty in the whole ordeal is i got a pretty good understanding of the electrics in this rig for any future issues.

Before it was fixed, if manual glow plug switch was engaged, the ignition and power circuits were getting enough extra from the 2nd battery to make of the difference in the shortage of current that was occurring due to the bad crimp.

Put fresh Rotella and filter on and been driving it the last couple of days.

I degreased the engine some, and may be looking at valve gasket replacement at some point. I get a little seepage on both sides it appears.

Thank you all for your input and time.