help me please

[jayrod1012]

so i have a 94 gmc 2500 with the 6.5, and i keep on popping the glow plug/gage cluster fuse. i put new batteries in it in january, and it’s been doing this since. starts fine hot but takes 15 minutes to start when it’s 60 degrees. any help would be appreciated. thanks!

 

[Will L.]

So isolating the problem is step one. Unplug the glowplug controller and see if the problem goes away. Unless someone hacked into your dash wiring this is the cause more often.

It does not mean go buy a controller- just buying parts and hoping will be crazy expensive by time its solved. Also we have learned there are ok places to buy and to avoid. Ask before wasting money. I can’t remember off hand the testing for the controller.

Are you getting any codes? Remember not all codes make the check engine/service engine soon light come on.

ONLY use AC Delco 60G glow plugs. Tons of info why if you want it. Remember to put a little antisieze on the threads during install.

Disconnecting glow plug wires and ohm them out individually. NEVER use regular wire to replace bad ones- it is a special wire.

There is a procedure for ohming out the glow plugs to see if they are good- however I have learned there is both false positive and false negative results so I only bench test anymore. So I install new set, test the old ones and keep the good and chuck the bad for the next go around.

The more details you can share the better off we are to help.

 

[jayrod1012]

i found the problem. it was a bad ground. cleaned it up, replaced 2 fuses and it fires right up and the gauges work. hell even the a/c works which surprised me.

 

[Will L.]

Awesome.

 

[jayrod1012]

it was really starting to make me angry. i have a lot of money in this truck. between injectors, pcm relocation, turbo, and other stuff. i was tempted to just throw the 454 i have in the garage in it. glad it was something simple. truck runs awesome now.

 

[JMJNet]

The importance of grounds in this truck.

 

[jayrod1012]

they will run like dog shit if it’s not grounded properly. i got a deal on this truck tho. i paid 2 for it and there is not a spot of rust on the whole thing. paint isn’t faded or peeling, it’s 4 wheel drive, and i think it’s as optioned out as you can get them. power seats, cruise, a/c, cassette deck, power windows, the whole shabang

 

[Will L.]

Nice. But don’t ever swap it to gas. People want them bad and if you stick around here you will see 1 per month people saying “HOW DO I CONVERT THIS GAS TRUCK TO A 6.5 DIESEL?”

Sell it and buy a gasser if you ever hit your limits.
Until then, stick around and learn a ton about it to make it better and last longer.
Let us know how ya use it and what you want to improve and we can walk you through so you don’t waste money and time learning like we did.

 

[JMJNet]

If you are in the other forum, first answer will be check the grounds.
As it is, you may still want to clean the other ground.
Take the connectors off, hit them with brake cleaner and wire brush it as needed.

If there is still plastic cover on the battery terminal, peel them off and wire brush the terminal to bare metal.
It is usually full of corrosion/rust.

 

[jayrod1012]

Nice. But don’t ever swap it to gas. People want them bad and if you stick around here you will see 1 per month people saying “HOW DO I CONVERT THIS GAS TRUCK TO A 6.5 DIESEL?”

Sell it and buy a gasser if you ever hit your limits.
Until then, stick around and learn a ton about it to make it better and last longer.
Let us know how ya use it and what you want to improve and we can walk you through so you don’t waste money and time learning like we did.

i plan on using the truck for daily driving, and towing my race car and boat with it. when i bought it the thing would barley pull hills. above 2500 it misfires like hell. still haven’t found that issue.

 

[jayrod1012]

If you are in the other forum, first answer will be check the grounds.
As it is, you may still want to clean the other ground.
Take the connectors off, hit them with brake cleaner and wire brush it as needed.

If there is still plastic cover on the battery terminal, peel them off and wire brush the terminal to bare metal.
It is usually full of corrosion/rust.

i put brand new batteries in it in january. battery terminals looked good.

 

[WarWagon]

and towing my race car and boat with it.

Welcome to the 6.5TD asylum: I am down the hall.

What non GMx turbo did you put on it?

Many mods to get one of these to tow the biggest concern being keep it under 210 on the gauge NO MATTER WHAT! Over 210 rings loose their temper and blowby starts. Hotter starts cracking things like block, heads, cylinder(s), till you scuff a piston or wipe the camshaft.

You got a better fan and a new low temp fan clutch?

2500 RPM misfire? Check for air in the IP return via a clear line. Check lift pump PSI as the OPS, Oil Pressure Switch, likes to fail from the lift pump current. Any smoke, use your mirror, when this happens?

 

[MrMarty51]

i put brand new batteries in it in january. battery terminals looked good.

I found that the battery cable terminal at the starter had some corrosion built up on it. Not like at the battery, a lot lighter than that, more like a bad discoloration. I sand papered it clean along with the starter post nuts and it made quite a difference in how fast the starter cranked over the enjun.

 

[Stoney]

@jayrod1012 what ground do you think was the problem? Or did you clean a bunch of them and not sure which one did the trick? I'm just curious...my truck is a electrical nightmare so always wanting to hear fixs