2nd Gen Non-Engine/Transmission '98.4 2500 - fuse #1 (parking lights) keeps blowing

[HoleshotHolset]

I haven't tried the e-flashers at all... I don't think I've ever tried 'em on this truck.



I replaced the following lamps (with dialectric grease) and checked all of these connections tonight:

1. Front turn/marker lights - replaced with 3057NA... should be less draw than 3157NA
   
2. All 5 clearance lights - 194
   
3. Rear turn/marker/stop lights - replaced with 3057
   
4. Left license plate light - 194
   

Every socket I looked at tonight was perfectly clean - except for one. What I found was the right license plate socket had some corrosion in it... so I took the lamp out and left it out. The left side was clean and had no bulb in it (weird... ) so I put a bulb in it and it was fine.



All seemed to go well... I had the marker lights on the whole time I was swapping out all the lamps and the fuse never blew. I took it for a ride and about 3 minutes into the ride... . POP! There goes the fuse again... I slapped a fuse in it and went back home... the lights were working when I paaahked it.



This is the longest I have been able to make the fuse last... but at $1. 57 per 5 fuses... this isn't the most economical way to keep my marker lights lit.



Under the hood - I found this miscellaneous relay hanging out by the distribution box. Lookie here... it's all corroded - gee I wonder if having it mounted sidways had anything to do with that!!! (Some people haven't yet grasped the idea of mounting relays with the contacts facing DOWN so that water will drain out... ) I'm under the assumption this is some sort of fog light relay (in addtion to the OEM relay in the dist. box?)... because my fog lights don't work anymore and they always used to... This relay setup doesn't look like OEM... but it is well terminated and has wire loom on it...



I had a heck of a time getting the relay out of the connector... everything was corroded up quite nicely. I got it out... and made sure that the fog light switch was off for the rest of my work out there... but the SOB still ate a fuse after everything I did tonight.



Tomorrow's plans are to investigate the fog light relay some more and trace all of that associated wiring/BS.



The saga continues...



Matt

 

[HoleshotHolset]

Well - after I blew the fuse (and replaced it) last night just before I drove home... and after driving it during the day and for 20 miles at night tonight. The lights still work... very odd.



Today must have been my lucky day with wiring... The lights in the basement haven't worked since I first looked at the property... somehow I fixed 'em this afternoon.



I'm not done with the truck yet... as the fog lights still don't work. I'm going to try to dig into it tomorrow...



Matt

 

[JoshPeters]

Ya know Matt... If you were closer, I'd grab my Benz wiring kit, my DVOM, and my ammeter and give you a hand. My suggestion would be this. Take all the bulbs out... and go for a drive. If the fuse pops... guess what... . intermittant short to ground someplace. If it stays good, one by one put the lights back in. It's kind of a slow process, but it should help you. It sounds to me like an intermittant short to ground. How about the HVAC controls... do they go out too? Radio..... you see where I'm going with that. I'd be looking at the dimmer for the Radio... . I've heard of odd ball problems with them.



Josh

 

[HoleshotHolset]

Well - the lights are still working.



Josh: What's in a Benz wiring kit? Does it come with kraut or something?



I did notice the AM/FM radio flickering in an odd way a few times tonight. It was doing that BIG time when the fuse originally started to blow... . hrmmm... What's the deal with the radio illumination? Have other people had issues like this?



When the fuse blows... I loose the marker lights (front/tail, clearance), fogs, gauge cluster, HVAC and radio illumination all at the same time.



I haven't had a chance to dig into the fog light wiring yet... no rush...



Matt

 

[JoshPeters]

My Benz kit has all the different connectors and leads I could possibly need. From the very very tiny needle pins for an Airbag unit to the large flat style like a relay has.



As far as the Radio goes... . I've just had a couple radios cause problems. It gets warm and that's when the problem starts. Next time it pops, try taking the radio out.



Josh

 

[HoleshotHolset]

That sounds like a cool kit, Josh. I need to start stock piling stuff like that... I'm like a fish out of water here in the Midwest compared to when I was leeching off Dad's goodies. :-laf



I'm not opposed to ripping that OEM radio out... I ate one in my '94 and this one is starting to act up with the funky display...



Matt

 

[JoshPeters]

Any issues lately Matt?



Josh

 

[HoleshotHolset]

Nope. The fuse has been intact for almost 5 days now.



Every now and then, the AM/FM display is still flashing very brightly when I hit a good bump in the road. Other than that... no issues at all.



Matt

 

[JoshPeters]

Sounds fishy to me.



That might be your problem... .



Josh

 

[HoleshotHolset]

If it happens again - I'll yank the AM/FM and repeat.



Matt

 

[JoshPeters]

If it happens again - I'll yank the AM/FM and repeat.



Matt

We all knew you got off on these trucks... but that's just sick! :-laf :-laf :-laf



Josh

 

[HoleshotHolset]

That's okay JohnRV4 was making fun of me at the last GTG about polishing my tailpipe in public. :-laf



Matt

 

[jrobinson2]

Last Friday I spent an hour and a half on the side of the road chasing this problem, on my truck it ended up being the tail light harness right at the RH tail light. The wires to the upper bulb cross the wires to the lower bulb and the tail light wire and ground wire for the reverse lights had worn a hole in each other and shorted together, they had been bouncing together causing an intermittent short for about a month before finally shorting out completely. To find the problem I ended up unhooking the main connector under the front of the cab and all the connectors to the tail lights, park lights, license plate lights, etc, then reconnecting them one at a time until the fuse blew.

Jared

 

[HoleshotHolset]

I don't know why my last reply to this thread didn't go through. Oh well...



The fuse blew last Saturday night on the highway. Once I got to my destination... I ripped the OEM am/fm head unit out... replaced the fuse... and it was fine then and was okay for the trip home.



After that - I drove it during the day on Sunday and it was fine... I haven't driven it since then... but I'll keep ya'all updated.

"... the tail light wire and ground wire for the reverse lights had worn a hole in each other and shorted together... "

That's a good find, man. I'll have to check that out (and hopefully keep that in mind... ) on my truck...



Thanks,



Matt

 

[HoleshotHolset]

I think I found the short!!! Check your truck!!!

The #$&! fuse blew on a trip tonight... 5 minutes from my destination. As usual, I dug into it. I took the tail lights out of the truck again... looking for chafed wires like Jared found on his truck... I couldn't find a darn thing wrong back there... so I climbed underneath and started tracing wires... nothing. All this time... the new fuse was in and it hadn't blown the whole time...



Back under the hood I go... I jiggled the fog light harness again - nothing. THEN - I grabbed the big wire harness underneath the ABS doo-hickeys and gave it a jiggle... ZAP!!! BINGO!!!



With the fuse blown and the headlight switch off I started investigating... and found a short! There's a bracket that holds the whole ABS shebang to the inner fender - the big wiring harness that runs underneath had shorted out right against the bracket... I could see the toasted wires! There was no wire loom or anything on the wires... not for long!



I took some pictures of what I found with my cell phone... the pictures are bad... but give you an idea of where to look on your truck. I'm confident my truck isn't the only one like this...



HUGE thanks to all that have helped me with this over the past month or so...



Go out and check your truck!!



Matt

 

[JoshPeters]

Nice Catch Matt!





Josh

 

[lowboy]

Well this is all interesting. I just got back from Colorado with a 2002 3500. Had the headlight switch get so hot that I was worried about it smoking! Rolled the dash light all the way bright and that cooled it down to the point that I was as worried, but the switch still heated.



I thought I remembered something about a recall on the headlight switch, but I see that it was just up to '97. Looks like they've still got the problem... .



Now this truck has the factory trailer towing package (at least it looks factory, I'm going to have to look at the window sticker) so it should have the trailer/marker light relay to take the load off the switch, right?



Don

 

[HoleshotHolset]

Now this truck has the factory trailer towing package (at least it looks factory, I'm going to have to look at the window sticker) so it should have the trailer/marker light relay to take the load off the switch, right?

The trailer towing package (as far as the wiring is concerned... ) only includes the wiring at the back of the truck that enables you to plug in a trailer... it more or less is just a pigtail that plugs into the existing wiring on every truck.



If I understand the situation correctly: The '97+ trucks do not have the relay that takes the parking light load off the switch itself. They just have an updated headlight switch. The recall kit [#819... I think](or the Summit kit... ) is the only way to take the load off the switch for good.



The heat from the interior lights dimmer is one issue. The heat from the load (from the parking and head lights) across the switch is a whole 'nother issue. Both of these heat producing loads makes for lots of switch/wiring fire inducing heat.



Matt

 

[jrobinson2]

My '99 with tow package did come with a relay for the trailer tail/marker lights. On my truck the key needs to be on to close the relay, the trailer lights dont come on with the tail lights if the key is off, A few months ago I spent about 45 minutes trying to get tail lights on a trailer before they magicly started working when I turned the key on to check the turn signals ...

I looked at a "trailer wiring kit" for a '99 at a dealer once all I can remember it having was the relay, trailer connector, and trailer brake controler pigtail, no wiring at all.

The relay is in the power distribution center under the hood, it's the closest to the fender in the rear row.



Jared

 

[lowboy]

Matt and Jared,



Thanks for the responses! I'm going to have to dig into this deeper. The trailer I was pulling didn't had nearly the running lights that the gooseneck I'm going to buy will have, so... .



Looks like I need to add a relay for the trailer lights, possibly one for the headlights (or certainly one for the fog lights) if I find that there aren't any from the factory.



Then I've just got to figure out the dash light dimmer problem, because I can't stand the dash lights on full bright at night.



Don