'98 Suburban K2500 454ci

I've had this thing for about two years, and posted in the newbie introduction section about it. There's a couple minor dings in the bodywork, it's gonna need a new roof in a year or so, and it's got a couple mechanical/electrical issues, but I still love it.

Still having issues with it not wanting to crank. Either it cranks and starts just fine, or it won't even try cranking, but the radio and everything else works just fine either way. Starter's been replaced, battery's been replaced, and last weekend a friend who works as a mobile mechanic came to visit. He reached down under the engine, loosened a ground wire attached there, scrubbed the end, and reattached it. And while this was happening, I refilled the radiator and coolant reservoir because both had emptied out. Turns out a hose fitting on top of the engine is a little loose and needs to be replaced.

Did that fix-up on the ground wire alleviate the no-start issue, or too soon to tell?

Sounds like your heater hose quick-connect is failing.. I'd address that immediately before it lets go. Just beware they are notorious for breaking off in the intake, making it a headache to deal with. Better deal with it now, than before it lets go and you ruin your engine with a sudden overheat.

Richard

I like the truck - that two tone looks great on these things. I always like how the 4x4s sit a bit more level than the 3/4 ton 2wd like mine. Keep after it, I'm really starting to appreciate how nice these trucks are.

someotherguy said:

Did that fix-up on the ground wire alleviate the no-start issue, or too soon to tell?

Sounds like your heater hose quick-connect is failing.. I'd address that immediately before it lets go. Just beware they are notorious for breaking off in the intake, making it a headache to deal with. Better deal with it now, than before it lets go and you ruin your engine with a sudden overheat.

Richard

Click to expand...

The ground wire fix seemed to work when I drove it Monday with no problems, but it failed to crank Tuesday morning so I just took my Patriot to work like I usually do. Planning on stopping by Autozone to grab the coolant hose connector today.

The failure to crank but radio and other accessories working could be a few different things. I'd inspect the battery cables closely. There's a double positive connection that can be problematic on the Vortec-era trucks like yours.

Originally the cables have a covering over the terminal end and a spacer between them, the spacer gets soft and causes a loose connection, also the coverings can hide a lot of corrosion before you might notice. Often people cut the coverings off and ditch the spacer then pick a shorter bolt to attach the two positive cables. If you go this way, be careful with the bolt length so that you don't damage the battery terminal. Be sure to really clean the terminal ends - CRC makes a good terminal cleaner product you can spray on and rinse off, including one that turns colors if there's still any acid present, so you can clean again as needed.

Starter relay is an inexpensive one to rule out at only about $5.

The two above things are low cost efforts at solving simple problems; beyond that I'd dig into the service manual for testing the following items before simply throwing money at the problem. You can find scans of the factory service manuals available for free download in the "Engine" section of this site; look at the top of the post listings in the "sticky" posts.

If the cables and connections are in good order I'd suspect the starter solenoid next, though they're not as notorious for failure on the mini-starter your '98 likely has, vs. the older large starters. They do still go bad but in my somewhat limited experience, the starter motor itself tends to start dragging long before the solenoid goes bad. The solenoid is serviceable as a separate item for about $50-$60 but vs. $100-$160 for a whole new starter.

Next suspect, ignition switch. Not the key tumbler, but the electrical portion inside the column. A bit involved to go inside the column for replacement but not terrible. About $75-$100 for the switch.

Richard

I switched to a top post conversion setup with the new battery, albeit with the existing side post wire ends hooked up to adapters using lock-washers and new bolts, so that seems ok. And there's actually four wires coming from the positive terminal, two of which are smaller and probably connected in some way to the trailer brake controller that a previous owner would have installed after buying the vehicle.

My mobile mechanic friend has looked at it a bit, made sure the battery connections are VERY tight, cleaned off the ground wire on the bottom of the engine, etc. For a couple weeks, it was working fine, now it's not. Quick connect hose was finally replaced last month, so I could drive it when it started, but for whatever reason it's just not cranking. Maybe it's got a sensitivity to moisture? Been raining kinda heavy here lately, and it didn't really wanna try cranking over the winter with few exceptions. My brother suspects it may have something to do with a safety switch under the hood for a remote start system that I'm guessing is aftermarket. Mobile mechanic is gonna swing by tomorrow evening, Lord willing, and try tracking the power down. Earlier today, he called me and suggested I try starting it in neutral in case that was the issue, and wiggle a wire on the side of the transmission. Neither idea worked. And the ignition tumbler idea was also brought up, idea for a solution being to shove the key in a bit harder to ensure contact when trying to start. That didn't work either.

It finally did the thing while my mechanic friend was standing there. He opened up the fuse box and wiggled the starter relay......that was the issue.

RossoRacer said:

It finally did the thing while my mechanic friend was standing there. He opened up the fuse box and wiggled the starter relay......that was the issue.

Click to expand...

Was any corrective action taken? At minimum, I'd pull the relay and spray some DeOxit in the socket and on the relay pins, and re-install. Or, replace the relay (as well as spray some DeOxit in the socket.)

Richard

He swapped it with the AC relay(was ~85F outside and sunny at the time), and told me to go buy another relay or two for like $10-$15USD each at AutoZone or someplace.