sorry for the long post

hello everyone, i have a 1982 gmc 3500 crew cab dually with a 6.2 diesel. i picked up the truck about 3 weeks ago. the truck is doing good but some issues have recently surfaced.

1. the glow plug light on my dash no longer turns on. the light used to turn on, now it doesnt. the truck still turns on with no problem. does the glow plug relay have anything to do with this?

2. the truck has 2 gas tanks. the left side gas tank had a hole, the tank would leak a little diesel so i thought no big deal, so i had the right gas tank "activated'. well i was driving on the road one day and the truck shuddered and shut off, similar as to when you run out of gas. i put diesel in the right tank and the truck started. i was driving and once again it shut off. after towing the truck home, i thought it was the fuel pump because i had put about 40 dollars of gas on the right tank. i decided to change the left tank for a used one and as i was moving the left tank, diesel started pouring out, needless to say there were about 20 plus gallons in the left gas tank with the hole in it. i'm thinking the reason it felt the truck was running out of diesel was because the diesel was being pumped into the left gas tank when it was running. my problem now is i put the 20 plus gallons back into the right tank. when i start up the truck and have the right tank activated it feels like its starving for diesel then shuts off. i activate the left tank and it runs fine, although the left tank registers empty. what could be causing this. i want to see if its anything i can do before i take it to a shop.

3. i bought this truck to pull a 6000 pound fifth wheel. can i pull it with this truck or did i waste my money??? be honest

thank you for any suggestions..

I think you'll find that you upgrade to a 1985-1993 6.2 electronic glow plug system,you'll be glad you did.There is far less wiring involved than older models and since the controller is simple and reliable,you'll never have to worry about your glow plugs not operating.I can send you a wiring diagram on how to wire things up if your interested.

3- My uncle pulled a 14,000lb fifth wheel with his 6.2 Chevy. Didn't have as much power as he really wanted but pulled it just fine IMO.

2- I'm not completely familiar with the fuel system on your truck, but there should be a 6 port valve underneath, probably near the fuel tank. If the return lines got switched, you'd get fuel from one tank moving to the other. Also, does the right tank starving problem happen right away? If it does could be drawing air from a faulty fuel line or 6 port valve. If it takes awhile try running it with the cap removed to see if the tank is not venting.

1. the glow plug light on my dash no longer turns on. the light used to turn on, now it doesnt. the truck still turns on with no problem. does the glow plug relay have anything to do with this?

2. the truck has 2 gas tanks. the left side gas tank had a hole, the tank would leak a little diesel so i thought no big deal, so i had the right gas tank "activated'. well i was driving on the road one day and the truck shuddered and shut off, similar as to when you run out of gas. i put diesel in the right tank and the truck started. i was driving and once again it shut off. after towing the truck home, i thought it was the fuel pump because i had put about 40 dollars of gas on the right tank. i decided to change the left tank for a used one and as i was moving the left tank, diesel started pouring out, needless to say there were about 20 plus gallons in the left gas tank with the hole in it. i'm thinking the reason it felt the truck was running out of diesel was because the diesel was being pumped into the left gas tank when it was running. my problem now is i put the 20 plus gallons back into the right tank. when i start up the truck and have the right tank activated it feels like its starving for diesel then shuts off. i activate the left tank and it runs fine, although the left tank registers empty. what could be causing this. i want to see if its anything i can do before i take it to a shop.

3. i bought this truck to pull a 6000 pound fifth wheel. can i pull it with this truck or did i waste my money??? be honest


Welcome to the forum! Sounds like you've got a good truck to start with.

I think you will find that if you replace the bulb in the glow plug light, it will work again in most cases where the truck still starts fine. :)

I feel for you on the rusted out fuel tank. That happened to mine, too. I smelled like diesel for days.

As JOAT said, if the return lines got switched that would cause the fuel to be transferred from the right tank to the left when you are running on the right tank. Keep in mind, however, that the fuel will also be transferred from the left tank to the right when you are running on the left tank, and that this transfer will, in either case, take a while. Are you sure that the fuel is being transferred? Are you sure the left tank was empty, or did the gauge just read empty? The gauges can be rather troublesome, and they are sensitive to grounding issues. In addition, the sending unit has been known to fail on occasion, which will cause the gauge to read incorrectly.

You should be able to tow that much fairly easily. Don't plan to break any speed records, but you'll be able to pull it pretty easily. What you will love is the fuel economy. In a reversal of the saying "passes everything except gas stations," I'll say that it will "pass nothing but gas stations." :D

thank your for your responses

i changed the light on my dashboard and the glow plug light still does not turn on. i have noticed that there is no more clicking on the glow plug relay, but the truck still starts up fine. i'll replace that next.

as far as the possible mixed fuel line hoses, how can i tell what hoses go connected where? i know there's 3, but how do i know if i am reconnecting them correctly. i did buy the chiltons cd, but it does not get that specific??