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Help! Electrical Problems

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by bassplayer4x4, Mar 2, 2002.

  1. bassplayer4x4

    bassplayer4x4 Registered Member

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    Ok, ordered a new wiper washer switch as there was not one in my vehicle. Just a hole in the bezel. Installed switch, hooked to motor via lt blue, dark blue, and black wires. Turn on switch and motor begins moving wipers, however switch has no effect on them -- they won't turn off. Take switch out, wipers don't work at all, touch switch assembly to dash and wipers work -- it arcs between switch and dash. I am assuming grounding problem somewhere. I took out my multimeter and touched it to wiper switch and to dash bezel read about 25 volts...I noticed that when my motor was rebuilt the battery is not grounded to frame, but grounded to block? There is a small lead off the neg battery terminal hookup that I could extend and hook to frame somewhere -- any ideas? Also looks like entire dash electronics are grounded to the big brace under the steering wheel. Bad place? Horn does not work either, but I figured that was in the button, some gauges work -- some don't, fuel works but reads backward (reads full when tank is empty) Speedo and tach work, battery/alternator work, niether of the two temp guauges work, oil pressure works. Advice? Ready to pull my hair out. But don't want to take it to the electrical guy in town -- he is expensive...especially if this is an easy fix.

    Also looks like my fuse block was updated too, has fuses for power windows and stuff which was not around on my year vehicle. I am thinking a full wiring harness redo when the restoration was done.

    Phillip Bunton 72 K5 and 4Strings

    But honey its cheaper than car payments!!
    72 K5 - my First First Gen -- 4 K5's to date...
     
  2. Steve_Chin

    Steve_Chin 1/2 ton status

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    The main ground gable does indeed go to the block near the water pump. The factory set up a secondary ground wire to the passenger side fender support, about 6" behind the battery. This was mostly to reduce elestrolytic and galvanic corrosion, though. The cylinder heads should both be grounded to the firewall with flat braided copper cable.

    I'm not sure what to make of your wiper foul-up. The wiper motor should have power whenever the ignition switch is not in the OFF position. The switch merely grounds one contact or the other to select motor speed.
     
  3. bassplayer4x4

    bassplayer4x4 Registered Member

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    I will look for that ground to the firewall -- I don't remember seeing one. Would connnecting that secondary ground from the battery have any effect you think?

    Do you think the switch is possibly bad? Something not grounded in the switch?
     
  4. bassplayer4x4

    bassplayer4x4 Registered Member

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    OK. battery neg is connected to block below water pump - engine has flat brad connected to firewall from intake riser. Battery is not directly gounded to frame or to body. Check this out, when I tried to charge my batt - left the door/dome on all night - couldn't get any load to work until I gounded the charger at the radiator support ?? EVen when I hooked the charger neg clamp to alt support and to block, could not get batt to take a load -- once I hooked to rad support charger read properly and began charging batt. There is a PPPI new fuse block and harness in it, no telling what is hooked up and what is not...I just need wipers and my frigging horn to work so I can get an inspection and be legal...any thoughts on grounding anyone?
     
  5. bassplayer4x4

    bassplayer4x4 Registered Member

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    any body got any advice on this topic? I am stumped...
     
  6. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Phillip,

    I can't say that I know what's going on with your electrical gremlins, but one thing that DID jump out at me was your comment that the battery is not direclty tied to the frame for ground......that's definitely not right.

    The basic way the electricals work (and I'm not trying to be condescending, just want to keep it basic) is that the frame and body are connected to each other with a series of those "woven" ground straps.....since most truck bodies are sitting on rubber body mounts it's pretty well insulated electrically, so they added the straps to ensure that there is a ground path from all areas of the metal body, and the frame.....

    All those ground points need to travel back to the negative side of the battery. At least on my K5.....that means that there is an 18" wire coming off the frame and going DIRECTLY to the negative side of the battery. Also, there is a ground wire from the engine block going to that same frame ground.

    I'd say check to see where the negative side of your battery is wired (That's step 1).....look for signs of corrosion on the battery terminals or wires....that can cause HIGH resistance and all sorts of electrical bug-a-boos.

    The only other thing I can tell you is that there is a MASSIVE plug under the dash that connects to the headlight switch....as mine starting working loose....my dash lights got dim (some went out) and my fuel gauge stopped working. Once I re-seated it.....things got a lot better.

    Just some random ideas....I don't know if that's gonna solve your issue or not.

    I've got some high-res electrical schematics I can e-mail you if you decide to trace things "one wire at a time" /forums/images/icons/smile.gif
     
  7. bassplayer4x4

    bassplayer4x4 Registered Member

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    No wonder you made moderator!! /forums/images/icons/smile.gif

    I will add a wire from my neg side to the frame itself. My problem with the wiring in the first place is that they installed a Painless Products universal kit, its new, but most of the wires don't have the correct color anymore and some they just didn't hook up at all. I swear I even think the guy installed a power antenna, I just thought mast was broken off but while I was diggin under the dash I found a red and green lead not hooked to anything but going in the general direction of that antenna...of course I now have to identify the wires to hook power to my stereo from the PPI block before i can install. Well I bought it to be a project ; ) a daily driving project...

    Oh yeah, you were kind enought to share your thought on roll bars and soft tops with me -- just thought I would let you know my STC (Kayline) arrived today. I thought I would document the installation process and post the pics in the gallery since I became a member. Maybe I could contribute that way to the site.

    I will keep you posted on my electrical issues. I may end up having to take to an electrical shop to track all this down. Espcially since my gauges are not stock but VDO's.
     
  8. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Phillip,

    WOW! That sounds like a real headache! /forums/images/icons/smile.gif

    What's you're overall objective for the truck? It seems like you might be better off in "the long run" trying to buy an OEM wiring harness and gauge package and starting over. At least that way, you'd have wires that were the correct color, and the folks here could help you more.......

    Unfortunately, with something "aftermarket" it's really hard to guess what's going on.....the typical "been there, done that" experience of the list isn't applicable.

    Fortunately.....we're coming OUT of the rainy season, so it's not going to be as critical of an issue as it would if this were, say, September...... you have some time to evaluate how you want to address those issues.

    A certain amount of the "character" of driving an older vehicle are the little "quirks" it has.....I'm not sure if you find those things endearing or annoying. /forums/images/icons/laugh.gif
     
  9. bassplayer4x4

    bassplayer4x4 Registered Member

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    belive me I have thought about that. I think it would be pretty tough to find the original harness somewhere and probably cost a mint. I have seen the guage clusters in LMC, but for one with a tach and all is pretty high dollar too. Maybe if someone is parting one out. In NC we have to have inspections and wipers and horn is part of that...killing me...
    The gauge cluster now is really cool, polished aluminum and the VDO's if I could get it to work right I wouldn't mind keeping it. I will work with the grounding stuff that has to be the issue and would probably remain the issue even if I switched back to OEM.

    As for my goals, I want a very comfortable yet convertible vehicle to drive to work, drive to my hunting spots and maybe crawl some small stuff. Nothing major here...I will post some pics in a gallery and give you a look see.
     
  10. ntaj*ep

    ntaj*ep 1/2 ton status

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    Just a thought bro, first the grounds in the engine compartment sound like they are fine. As long as your "main" ground is connected to the block/head and you have a braided strap at each head to firewall, and under the core support to the frame your in good shape. Seconed, make sure you don't have a draw on the system (I don't think you do especially if your batt. is charged in the morning) but it's good to check for a parasitic draw. With every thing off, dome lights, switches, everything off, take your multi. meter and set it for amps. make sure its fused internally. Take your negitive batt. cable and loosen the clamp, connect one lead to that and touch the other to the actual negitive terminal. With the leads attached remove the cable end, and read the meter, it should not be more than .5 amps.
    Ok now you said the wipers work with the switch but do not shut off. I would check the wires going to the motor and the switch, The motor could have an internal short to ground, (which may explaine the high voltage reading). I am assuming the switch is new. Hopfully that helps you a little. As far as the horn, I would remove the lead going to the unit itself and connect a test light or meter, and hit the button if it lights up your horn is bad if not you have another issue. Hope you can fix this thing soon and enjoy the good life, that is.....topless cruzin!!
     
  11. bassplayer4x4

    bassplayer4x4 Registered Member

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    Thank you for the suggestions, I checked and I don't have a ground strap coming from both heads, as a matter of fact the only ground braid strap is coming from the intake riser that was added for my Edlebrock carbs. Got it that way.

    I only get the high voltage reading when I touch the wiper switch to the dashboard bezel and what really wierd is I don't get it when I touch it to the rest of the dash (which, as you know, is also metal), with the key turned to on. Its wacked because I pulled the wires and switch to the wiper motor out and just let it hang on the wire, no wiper motor function, touch it to dash bezel (which is polished aluminum) it arcs a bit, and wipers work but switch has no effect, touch it the rest of the dash no function at all. I unplugged checked for continuity and plugged all the wires going to the motor, is there a way to check at the motor (wiper) if it has a short? That thing looks like its a b*tch to remove and I haven't seen any replacement ones available.
    I will try checking for parasitic draw this weekend. I think I maybe have one. It wierd but after I charged my battery this weekend, my guage now reads about 16 when running, and about 13 at idle, I am wondering if its reading the output of the alternator instead of the battery. I also think that since I couldn't get a good charge until I grounded to the frame, the alternator may not be able to charge the battery well either.

    I HATE electricity -- thanks though for your time in helping me. supposed to be 70 this weekend -- I see a top removal party in my near future....
     
  12. BobK

    BobK 1/2 ton status

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    I've got ground going from neg. side of battery to block(by the water pump).Ran another ground from block to frame.Another from head to body.Also saw a factory ground strap from passenger wheel well to frame.No electrical gremlins for me.I made the battery to block, block to frame and head to body grounds from 2 gauge welding cable. ARG,ARG,ARG(Tim Allen grunt).
    Good luck.Electical prob. are a real PITA (pain-in-the-@ss).
     
  13. Skigirl

    Skigirl 1/2 ton status

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    I had the same wiper problem. It wasn't the switch. There was a short at the connection between the washer pump and the wiper motor. Check those plugs in the engine compartment and see if there's a problem there.
     
  14. bassplayer4x4

    bassplayer4x4 Registered Member

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    my washer pump and wiper motor are the same thing. I wish it was separated on mine like on gen 2's. At least it would be easier to figure out the problem. And its wierd to have a tube coming from outside the firewall carrying wiper solvent to the motor/pump inside the firewall then two tubes running back outside the firewall to the squirters. Engineer must have been hitting the LSD "back in the day"
     
  15. Skigirl

    Skigirl 1/2 ton status

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    LOL, yep, that's bizarre. Well, if it's not a switch, there's got to be something creating a circuit for it to run constantly. Hmmmm....
     
  16. bassplayer4x4

    bassplayer4x4 Registered Member

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    AUGGGGH

    Ok, this just plain sucks now. I spent the evening running two new grounds to the frame and to the body from the battery. 8ga wire, sanded the areas down for complete metal to metal contact. Same frigging problem with the wiper motor --- and now my gas gauge reads differently. I guess I am going to have to break down and get the ol gal to a electrical specialist. Unless any of you guys have other thoughts. Anyone know where I could find a wiper/washer motor if mine is shot (shorted)? LMC doesn't carry them apparently...
     
  17. Triaged

    Triaged 1/2 ton status

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    I got a universal wiper motor for mine. It is a electrical motor that goes "in-line" with the hose that runs form the tank to the squrters. I like the electrical kind better than the stock ones any way. I still haven't gotten it in...but at least I never run out of wiper fluid:) Most of the time I just use a sports bottle over the windshield because I never use the top.
     
  18. bassplayer4x4

    bassplayer4x4 Registered Member

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    hmm that sounds like what is in mine, on mine the hose from the tank comes through the firewall and into the wiper washer motor/pump then back out to the squirters, is that not how the stock ones worked -- but my seemingly stock plug works with this one...? Where did you buy yours?
     
  19. Ryan B.

    Ryan B. 3/4 ton status GMOTM Winner

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    This sounds a little like a problem i had...
    Now that you mention your gas gauge going weird...

    When I first bought my camaro, I had no dash lights, the gas gauge would only read if the lights were off, as soon as i turned on the headlights my gas gauge would go all the way full i think.
    IT turns out it was a ground from the gauges to a hard ground. I ran a ground wire from a screw on the back of the fuel gauge housing to a good ground and fixed the problem.

    Looking at a wiring diagram for the blazers windshield wiper/ pump circuit...
    It looks like there should be a yellow wire that runs to the windsheild wiper/washer motor. This is your B+ When in Run OR Acc.
    Get a test light and probe this yellow wire to make sure it is only HOT when in Run Or Acc, and it goes to 0 volts when the key is off.
    It also looks like the whole circuit is grounded by a case ground through the switch on the dash. This would explain your arc-ing you're talking about when you touch that switch...
    I'd say tighten up how that switch is secured to the dash since it appears that it's getting a case ground.
    Or you could try a jumper wire from a known good ground to the case of the switch and see what that does! /forums/images/icons/smile.gif/forums/images/icons/cool.gif/forums/images/icons/laugh.gif
    If you find that hooking up a ground jumper wire makes it work, but the switch has no effect it just continues to run, the Black, Dark blue, and Light blue wires are probally crossed and hooked up wrong.
    If that jumper ground fixes your problem you can always figure a way to hook up and run that redudnant ground. You can never have too many grounds. /forums/images/icons/smile.gif


    Good luck and lets hear what this does!/forums/images/icons/smile.gif
     
  20. bassplayer4x4

    bassplayer4x4 Registered Member

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    Yeah I checked the wiring diagrams in my book, didn't know what a case ground was though - thanks. What if I grounded the whole dash bezel to a good ground? Think that might fix the problem with my other guages? I get no reading on either of the temp gauges -- and I swear my amp gauge cannot be right, it reads close to 16 when I am accelerating! The whole instrument cluster is grounded to that big brace under the steering wheel, wonder if I ran it back to the firewall if that would help. Don't really know what that brace is hooked to on the frame-
    There is also so much paint on the frame from the resto I had to sand out some places to make my ground points.
     

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