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Wiring Demons...Please Help

Discussion in 'Chevy Trucks' started by guilty1, Mar 24, 2002.

  1. guilty1

    guilty1 Junior Member
    Messages: 29

    I have a 1978 K10 Chevy 1/2 ton, 4 speed. It wouldn't turn over, I tried my battery boost, but no luck, so I caught it in gear, all of the lights worked...thought it was the solinoid. Disconnected battery, removed started...noticed one lead was not connected, looked like wire is black, could this be a ground wire for the left hand terminal on starter? Took to the parts store, tested it, was good. Re installed starter, no lights, radio, nothing. Put jumper wire on bolt set up on fire wall (junction block?). Fan and lights worked. Reconnected starter, with red wire, engine cranked (without key being turned). This red wire that I connected to the right side of solinoid...shows continuity at redwire on back of alternator and on junction block?, There are 3 wires coming down to the starter, the 2 already mentioned and 1 that runs down frame rail. Looks like 3 or 4 wires on the right side of juntion block, and none on the left side. One has a fusible link and that one is the only one I have found. I tried to find continuity with the black wire that was not connected and had no luck finding where it goes. Any help would be greatly appreciated!
  2. CT18fireman

    CT18fireman Banned
    Messages: 2,133

    Are all the connections clean? Just because you show continuity or a hot lead with a meter or test light does not mean the full amps is able to get through. I would check all the connections around the battery and make sure all your grounds are good.
  3. gordyo

    gordyo Senior Member
    Messages: 527

    Fusible links can still "look" like they are good. Pull the wire on each side of the fusible link and if the link is bad it will pull right apart if its good it won't. I had a similar problem with a 1975 Chevy K10 and this was the problem with it. Link looked fine but wasn't.
  4. DaveK

    DaveK Senior Member
    Messages: 420

    Since the starter checked out ok, and assuming that the wire(s) to the solenoid are fine and connected correctly...

    It's possible that it's the starter switch (should be on top of the sterring column under the dash)
  5. guilty1

    guilty1 Junior Member
    Messages: 29

    Wiring Demons....Please Help

    I check some schematics that I found at http://www.cybrrpartspro.com/chiltonautolibrary/root/index.html. I am not sure if the red wire is supposed to be connected to the big middle lug on the starter with the cable from the battery, but I ran a fused hot wire from the battery to this lead and got my lights all on. I also ran a hot wire from the juction block on the fire wall to a switch and back to the right side of the starter (closest to the motor)...That will have to do for now. How do I check that starter swith? The clutch lockout switch...is it closed when it is compressed or when it is pulled open? Thanks! Great Forum!http://www.cybrrpartspro.com/chiltonautolibrary/root/index.html
  6. 75

    75 PlowSite.com Addict
    Messages: 1,382

    The clutch switch should be closed when the pedal is depressed (the switch itself will be "pulled open" but the contacts inside will be closed so the switch can transmit power) and open with the pedal up, this way power can only get to the starter motor with the clutch disenagaged.
  7. guilty1

    guilty1 Junior Member
    Messages: 29

    I found out what it was! It was clutch safety switch! I had no idea it even had one until I saw that schematic last night. The actual switch was not connected to the clutch pedal.:mad: I think I am going to put a jumper across that connecter and remove that switch all together!:D Thanks 75 for the tip on which way the switch was on. I really am quite impressed with this forum, Thanx all!

    Any suggestions on what kind of exhaust manifold studs I should use?