Well guys, I just bought a 91.5 dodge d250 with the cummins diesel and I need some help figuring out my problem: I turn the key on and sometimes my guages(wait to start, water in fuel,etc) don't light up or do anything and the truck wont start, then sometimes it works fine.... any ideas of what it the problem is I am having? The guy I bought it from said he turned the key on and it didnt light up at all, and his buddy was there, and used a jumper wire from somewhere to somewhere and it fired right up, but again he was an old man and didnt know what 2 wires his friend ran one across to touch both together. Again any ideas? I'm a new to diesel owner and any help would be appreciated.


thanks,
Jon

 

Sounding like an ignition switch. The two wires are red and brown. coming off the starter is a small brown wire that leads to a quick connection with that red wire. If your put power to the brown wire you can bump the starter. If the ignition switch will give power to the fuel shut off solenoid (FSS), then it will start and run. If there is no power to the FSS, you can run a wire from the + terminal to the FSS, then start it.

 

What dzl damon said will work...

You can unplug the brown and red plug at the battery and just jump the plug to bump the starter.

But it sounds like a loose connection somewhere is the root of your problem. Check the plug on the heavy black wire about 6" from the positive post. I think it's a 2/0 wire. Don't confuse the 2 slightly thinner gauge black wires bussed in at the positive terminal. These are for your grids.

 

ok guys will do, and thanks for the quick reply.

 

So the + to the fss needs to be live the whole time for the truck to stay running or does it just need an initial power to start the truck? Because if it needs power the whole time or the truck wont stay running I will run a toggle switch to keep it powered on

 

Power to FSS opens the fuel to the injection pump, so it must be energized the whole time. You must DE energize it to shut it off. Don't just shut the truck off with the manual lever on the side of the pump and leave the FSS powered, it draws enough to drain the battery overnight.

I had some major electrical gremlins and I'm rewiring a lot of it now. The previous owner rigged up a push button switch when his ignition switch stopped turning the truck over, but everything else stayed working. Eventually my gauges started going dead and the truck was shutting off. I jumped the FSS while 100 miles from home and watched the gauges jump and the GPS turn on an off (from the cigarette lighter 12v) the whole way home. Turns out I had 2 fried fuseable links, one not as obvious as the other. Both led to the ignition switch.

This black wire with the connector TIMMY22 is talking about feeds the fuseable links. I believe it's a 4 or 2 gauge black wire and it feeds into a little rubber block with 5 fuseable links. The links can either be burned through, or they are partially deteriorated inside. Only way to detect this is gently pull on them. If the stretch at ALL, the copper is deteriorated inside the rubber insulator.

I'm rewiring mine with large Maxi fuses. However you can rewire any toasted links easily enough, they sell them at Napa or any parts store cheap. Just get the same size (I think the colors are all the same for each size as well).

However, if they fry, there is a reason. If they lead to the ignition switch, then the most plausible reason is a bad switch. Good luck man.

 

DZL_damon- can you send me some pics of your wiring job, because I may copy it. Also an update went and put a battery in the truck and it started on the second turn after sitting for about a year!!!! I'm stoked! now I bought some diesel injector cleaner, oil change/fuel filter, any ideas on what coolant to use and thermostat? I want to get that done aswell.

 

check your battery terminals and cables, happens in the boat all the time, no click no nothing, give them a wiggle and it fires right up.

 

My wiring is not 100% done. It's new loose wires that are labeled soldered into the freshly wrapped and wire loomed wire harness. My fuse blocks are mounted, but everything isn't hooked up yet. I will be showing pics when I'm done, sorry it's not much to understand now. There is a write up in the sticky, but he went a little small on his fuses. You'll need maxi fuses cause the smallest one (white fuseable link) is 30 amp. Anyway, the concept is all there, just need to wire a larger sized fuse block (in my case, x2 4 gang blocks).

Definately check you wires and connection first! It's free and you should do it anyway. Shine up terminals with sand paper on the starter and starter wire. Shine up the connections on the battery end with the $3 wire brushes at NAPA. Put some vaseline or dielectric grease all over everything to protect them. I'm still putting my money on a bad ignition switch that may or may not have fried a fuseable link.

 

It is probably the IGN-switch; BUT, as soon as possible, clean up that fusible-link mess and get rid of them, replacing them with either circuit-breakers of fuses.

Like said, follow that fat black wire from the battery HOT back towards the left-side hood hinge.

About twelve inches from the battery, you will run into a connector in that black wire; un-plug, CLEAN inside and out, and coat with Vaseline.

Keep following the fat black wire and you will come to a "duck-foot" that splits the one fat wire into about five smaller wires of various sizes.

The funny looking wires immediately coming out of the "duck-foot" are the fusible-links.

The proper amperage will be printed on them (if you can still read it).

Cut that mess out and replace the fuse-links with fuses or breakers of the appropriate amperage.

By eliminating the fuse-links, 90% of electrical problems will go away.

 

^ thanks for the tip bearkiller, I just got back from getting an assortment of fuses to replace the fusible link problem. I am having my doubts of the ignition switch though after seeing the condition of the battery cable ends and battery I really think that that was the whole problem.

 

It is best, neatest, and easiest to first establish an insulated HOT junction/stud that is NOT ON THE BATTERY.

Connect this HOT stud to the battery HOT via a minimum 4-AWG cable and make all HOT connections, EXCEPT the big cable to the starter, at this HOT stud, instead of on the more corrosion prone battery HOT.

You can then connect your new fuse and breaker circuits at this HOT stud, instead of trying to splice into that fat black wire.

That fat black wire proceeds on across the fire-wall and is the charge wire from the alternator.

You will have to keep that portion of it intact, or replace it with something equivalent or bigger in size.

The fattish GREEN fuse-link completes the alternator charge circuit.

You will need replace it with a big fuse of about 150-amp.

 

I did the same thing BearKiller... I routed a 1/0 to a gold plated power distribution block and off that I'm giving juice to my x2 4 gang maxi fuse blocks, and receiving juice from the alternator through a 150a ANL fuse. Looks nice and neat (or it will when it's finished!).

 

I retract my previous statement about it not being the ignition switch, today it didnt want to start so I smacked the bottom of the steering column and the light came on and it started so it looks like Im buying a new one asap. I got a question thought will a bad ign switch cause your guages to move around? My volt guage was reading fine then would got to 0, then I swear I was hearing a click and it would read fine then got to 0 again....... also my gas guage reads different everytime aswell any ideas?

 

Could also be caused by the bad switch, or a flaky cluster ground connection.