1998 Blazer LS-137,000

I have been trying to correct what I think is an improper amperage draw (possibly parasitic, as I have an aftermarket stereo head unit and run power to speaker amplifier-Alpine MRV T-757).

Many variables in this equation. Here is timeline of my awareness of what goes on in the vehicle service/repair centers, symptoms, tests and checks performed, parts replaced, and repairs/modifications made...along with whom performed them.

May 2013:
I know very little about automotive repair.

Fuel Pump failure. Reputable service shop replaces with proper Delphi unit.
Shop says battery needs replaced, new AC Delco battery installed.

Sept. 2013
Still don't know sh*$ about automotive repair.

I install aftermarket radio. While doing so, I incorrectly connect my front right + speaker wire (solid gray) to the illumination wire from the truck (also solid gray)....didn't buy a harness on the basis that this is the last radio that would be installed and I will be the last owner.

Later that week, Girlfriend moves truck out of driveway to get her car out and leaves ignition in ACC position. 2 hours later, I go to start it and it appears that the battery ran down, so I put it on charger without a shut-off/maintain feature, gave it a slow 2 amp charge overnight....don't know if that would overcharge battery or not, charged it for approx. 14 hrs.
Starting and charging system appear to be operating normally after that charge. Don't notice radio problem till I drove at night (dont drive at night all that much, had kids....now im a homer) and had constant noise from front right speaker. All illumination of cluster and elsewhere still operated normally. Found and fixed issue with mixed up wires. Everything operating normally.

Winter 2013
Still clueless.

Starting issues begin.
Temperature seems to be related.I know cold temps affect cranking amps, but anywhere 40 F or below after truck has been parked for 4+ hrs, only get a couple of slow weak turns of starter, then the dreaded click. Either jump it or put it on new charger w/computer shut off/maintain feature for the rest of that year and the winter season of 2014....and 2015. When above 40ish....as I said before, everything seems to be operating normally.

June 2016
Thanks to this site and 200+ hrs. of reading I can say
I kind of know whats up...at least enough to realize how many times my parents or girlfriend or myself have been taken advantage of and in my book, stolen from by some automotive repair shops and in our case, 2 Dealership Service Departments. Now exactly how every component in my 460l works with one another, im still a bit fuzzy, but I now know what a solenoid is.

So I start testing for excessive voltage drop in the big 3. Was losing 1.6 volts from BAT+ to FUSE/RELAY CENTER, so I........

Replaced the BIG 3 and MEGAFUSE. Now only losing just around a half of a volt.

Modified alternator setup with sense wire to +terminal of UH-FUSE/RELAY CENTER. (THANK YOU CAPTAIN HOOK!!!!)

Replaced ignition switch(had intermittent steady SECURITY light and intermittent DTC P0740 and P1860) following book procedure on replacement and SIR DISABLING/ENABLING. As for the DTC's if they continue, I will check circuit continuity and voltage to TCC/PWM solenoid and if no issues there, I will clean the solenoid as I am due for new tranny fluid and filter....need a new seal between transfer case and tranny, as fluid has bled from tranny to transfer case...(had 50 oz. in it when I changed it last month) but that can wait a bit as I have protected my vacuum system with a newer switch for the front axle lock vacuum actuator along with a new "F" check valve plus another inline check valve on the run to the HVAC controller in the vacuum system.
Information suggests that an intermittent security light and/or an intermittent DTC P0740 can be caused by a failing ignition switch. With my starting issues and these two indicators, I thought a new ignition switch was called for whether it was bad or not. Have a feeling that along with the alternator mod the new ignition switch will probably solve my cold start problems. Wont know til it it gets colder i guess.

Replaced every incandescent bulb possible (except headlamps)with LED's, installed resistors on signal bulbs....then found GM flasher EP29 and made fun of myself for installing resistors.....then removed all the resistors.....then made fun of myself some more....then I felt dumb for a while.

NOW FOR THE PROBLEM AT HAND(AND YOU HAVE BACKGROUND OF SERVICE INFO.)
Illumination light in headlamp switch needed replaced (it hasn't turned on for some time). While installing a NEO 4MM LED, I shorted the contacts that receive the contacts from bulb base. It was daytime, my keys were not in ignition, I really didn't think to disconnect BAT-. But then I thought about the fact that that switch assembly has constant voltage on the dimmer wheel for when it is clicked all the way up for courtesy/dome lights.
After the install, all illumination lights inoperable, and turn signal/hazards inoperable only when headlamp system is on (parking lights or all lights). Ext. Headlamps/Tail-Brake/front Ambers all on and normal whether AHLS switches them or manually switched. When headlamp system is off, turn signals and hazards operate properly.
TURN and HAZARD fuses in I.P. FUSE BLOCK have continuity(plus they work when lights are off)

Replaced Headlamp Switch (without fogs by the way).

Illumination lights restored to normal. BUT STILL NO TURN SIGNALS/HAZARDS WITH HEADLAMP SYSTEM ON.
edit: Signal operation was nominal following ignition switch replacement.
High Beam switch works properly.
Cruise and wipers operate nominally.
Hence I dont think it is the multi-function switch and that is an expensive part to buy if I don't need to.

I appreciate you reading this long a&* post, and any information and advice is greatly and willingly accepted. Thank you in advance.....

Regards,

Ryan

 

*EDIT*
Have you tried putting all of the incandescent bulbs back in to see if there is something wrong with the LEDs you swapped in? I missed that you had swapped out everything to LEDs and did a bunch of schematic reviews to see what might be happening, typed out everything below, then decided to reread your post and found the LED swap which I would suspect sooner than a fuse or wiring problem.
*/EDIT*

I took a quick look at a few of my resources and couldn't find a link between the park lamps and the turn signals besides the ground which shouldn't be affected by a problem with the headlamp switch. There are two fuses that you could have blown depending on what you grounded in the switch; the HDLP SW (Fuse #1 - 10A - I/P Fuse Block) and the PARK LP (20A - Underhood Fuse Block). Both are hot at all times.

I would also suggest looking at (or better yet continuity testing) each of the fuses in the stop/turn/hazard/headlamp circuit. There are a lot of them and the lighting schematics are pretty involved so you may find one that is blown and causing some weird things to happen.

If all of the fuses check out properly, you may have wiring damage.

 

I have to ask, has it ever worked with the LEDs?

Have you put the stock bulbs back in, and does it work with the stock bulbs.

I don't have time to look up and analyze the wiring diagrams for the lights on yours now (maybe this evening or tomorrow), but some of these systems reverse the bulb under some conditions. LEDs only light with forward current, if the polarity is reversed, the LED won't light.

 

Thank you for info guys. I will get a hold of the wiring schematic for turn/hazard/tail circuit and will check all the fuses in said circuit, then recheck wiring at headl/front turns, and tails. I ended up having to use heat-shrink butt-spice connectors on tails after installing and uninstalling those stupid load equalizers, so I could have mixed up hots or grounds to top and bottom lamps? That might be my issue and as i type i want to go check it right now. Swartlkk I will check those fuses with my meter as the short I created was not very sparky if you know what I mean, so one of those fuses might be done even though it looks ok. Thank you for your time spent trying to find a possible short path on the schematics, I know how valuable time is and I feel honored that you did that for me. Racer, the turn/hazards were functioning properly after I installed flasher GM EP29, but when I put that in, I didn't have time to immediately remove the load equalizers. Prior to inoperable turns/hazards with the headlamp system on, I removed the load equalizers and as i said earlier, had to use bs connectors on the tails. On front ambers I simply just removed those wire tap type stab connectors, I could possibly be leaking out of one of those hots to the headlamp ground as I believe the headlamps are grounded to cage around radiator? Not sure but cleaning that up is another thing I will do. I used all Sylvania Zevo on exterior so I was able to match up polarity as that line comes with + label on side of lamp.
Last thing is when I have the tails/front turns out, I will swap the old bulbs back in and see what happens.

Thank you again for the info./advice....sometimes just getting other viewpoints helps find the issue and helps me realize what I messed up along the way. I will let you guys know when (or if) I get them flashing with lights on.

Regards,


Ryan

 

All right. Problem corrected, and I believe I can provide details that might help anyone converting their exterior lamp type to led.

First of all, this problem was created by me....of course. Lets start with the operation of the side marker lamp. When the headlamp system is off, this lamp flashes synchronically with the front turn signal lamp...(with my 2nd Gen Blazer LS...the front turn signal lamp would also be considered the truck's parking lamp....wonder why GM didn't put a bulb socket on the inner half of the amber assembly....looks too empty in there....maybe those fancy LTs got em....legally only a parking lamp if one was in their Blazer, with the DRL and Automatic Headlamp systems disabled, with their headlamp switch toggled to the parking lamp position. It annoys me when I see vehicles and sometimes even rigs driving with only amber lamps illuminated in the front...to do that is actually a violation and in my state it is grounds for a traffic stop. Parking lamps describe their purpose, (so the other people that payed attention to their Drivers Education Instructor that are driving toward the front of your parked car with the front of their car(oncoming) can somewhat assume that your vehicle is not moving or...um.....eh......oh ya........parked) as fog lamps describe their purpose. (it is not illegal to drive with your fog lamps on when its not foggy just in case you didn't know....(making fun of myself for the longest parenthesized sentence I have written since college (which was a long, long time ago). Back to stuff that matters...side marker and front turn.....those lamps flash at the same time when the headlamp system is off. With headlamps or parking lamps on, these two lamps operate asynchronously. Well......being so busy with my Daddy Daycare duties, I did not remove any of the led load equalizers after popping in flasher GM EP29 (led flasher, up to six bulbs, trailer friendly). All signals functioning as they should. Got cut short of time (damn kids....kidding, my kids are pretty ok dudes and they take precedence over non-critical vehicle stuff) when I was removing the load equalizers so only the 4 in the tails got removed, leaving just 2 in the front....did not install them on the side markers, as after installing them on the front turns (aka...park-ers), the hyper-flash was remedied. So, with tails wired back normally, and load equalizers on front turns, but not side markers, with flasher GM EP29 installed, turn signal and hazard systems operate nominally with or without headlamp system, with led bulbs installed in the respective lamps (the ones that flash when one of the two systems calls for that due to an input (e.g.- driver moves multi-function switch up or down). Whew.....still with me?

So then I park the Blazer for start of this ongoing overhaul....new front hub assemb., new vac lines, ignition switch, egr and pcv valves, oil and filter, transfer case electric switch for 4WD vac actuator, transfer case and tranny fluid drain and fill, some new gear oil for differentials, new battery and cables, clean up some rust, and finish interior led conversion....you get the idea....point is, truck sitting in same spot it was a week ago, doing all this when the kids go to bed and trying to keep the other half happy and grab some sleep in there somewhere...oh, and me being quite distractable (you didn't notice?) I didn't recall that I removed the 2 load equal. in the front....(first thing I did before putting it up on ramps). Also note that all of the led bulbs installed in exterior lamps except side markers were polarized....the side markers were not.

Earlier (11PM CDT) when checking wiring, I noticed a faint flicker coming from side markers with headlamp system on and my left turn signal on, so I pull the bulb and like magic.....left front turn and left tail start flashing....so....do I dare say more? I am going to try polarized 194A's in the side markers to see if they will flash asynchronously with front turns instead of inhibit the flash of the selected side and hazards as well. Will post result of that installation in one sentence. Lastly....if doing led swap....back up lamps need to be the 3056's.....some brands will add compatibility bulb numbers on top right of package, but when installing led, unlike incandescent, have to have 3056, not 3156 or 3057 or 3157 which would all work for back up if incandescent.
Maybe you laughed once while reading? Once? Maybe? Damn.

Thank you again for your time, much appreciated....

Regards,


Ryan

 

Wow I talk way too much. Okay on the whole side marker front turn signal thing. I reinstalled the load equalizers on the front turns and everything is operating normally as long as the bulbs are not I repeat are not polarized. I happened to use the pilot brand of 194 Amber LEDs. Note that if you go to Sylvania Zevo route... that line of 194 Amber's as well as all the other Zevo 194 bulbs are polarized... when using that type of bulb... whether you have or don't have load resistors installed on turns and side markers when the headlamp system is on they will operate properly and Flash asynchronously with each other... that being the side marker and turn signal. With the headlamp system off and using this type of bulb only the turn signal bulb will Flash cannot get side marker to flash synchronically with the turn signal. So my advice would be order unpolarized 194 ambers from super bright LEDs or another vendor who offers the pilot brand. So to summarize one last time retrofitting your Blazer with all LED exterior bulbs make sure that you pick up GM flasher EP 29 at a cost of $15... Pick up a set of load resistors and install them on the front turns only not the side markers... And use the unpolarized in the side markers that being 194 Amber type LED bulb... For backup lamps you must have 3056... 3057 3156 3157 will not illuminate when called upon... Only the 3056 illuminate properly when called upon... I happened to use the Sylvania Zevo line... as I'm sure it's been discussed and many other threads LED light is very wavelength specific... So unlike halogen incandescent s... Which emit the full white light spectrum... You need to use red LEDs in the tail lamps... If you go with white your tails and brakes will appear in between Amber and red and the national highway traffic safety administration says that we're supposed to have a couple of lamps that are red... Not a red blend... Displayed somewhere on the rear of our vehicle. Okay I am done talking finally... Thanks to all that help me out and I hope this information I'll be it time consuming and annoying to read might help somebody who ran into the same or similar issues that I did.


Regards,


Ryan westermark

 

The best color LED to use in the tail lamps is red/orange.

Its really tough to get the side marker lights to work on these vehicles because there is no dedicated ground for them, they are grounded in the flasher unit and work basically as a switching ground (cutting the power on and off)

Thank you for all the information you provided. I just wanted to add to it.