Electrical problem, 454 Chevy power at dash


bax

New Member
I have an older 1984 class A Revcon with a 454 power plant with HEI ignition system. I replaced the water pump and along the way decided to upgrade the low amp altenator (64-72) with a higher amp guy (94-100). I also replaced a rusty old Solenoid mounted just under the hood, the positive side cable going straight to the positive terminal on the brand new, fully charged battery. New parts in place and now I can't get the key switch to throw juice at the solenoid to crank the engine. No head lights, and nothing at the dash panel, stone dead. I put a jumper wire from the positive side of the solenoid to the opposite side going to starter side. with the jumper in place I got power to the dash and the headlights worked and when I hit the key the solenoid click. There is a black wire that appears to be a ground wire at the solenoid but I can't firgure where it goes. I remember it being attached to the small "I" post but it has a large opening connector? There is a purple wire going to the small "S" and that seems to be connected to the Key switch, then there is a second purple wire with a large connector going to the battery cable post opposite the Positive post connection and it goes to the starter, it is the starter wire. When I jump from the hot side to the starter side the starter cranks and turns the eingine no problem. I have to remove the starter wire from the large post in order to jumper from the hot side so as to keep the starter from cranking, then I can switch the key to start position and the solenoid clicks.
The black wire placement has me baffled, does it really belong to the "I" post? Also, is it possible the new altenator could be the problem? Everything had been working fine before replacing the altenator and the solenoid. When I first attempted to start the engine after the new parts there was nothing, no clicking, no buzzing, nothing, just dead silence. I called the parts counter guy and he says the altenator shouldn't have anything to do with getting power to the key swtich or the dash? Has anyone ever run this same problem? Help if you can, Dan
 

C Nash

Senior Member
Electrical problem, 454 Chevy power at dash

bax, the alt should not cause the problem. Think your problem will be in the way you have connected the wires on the sol. Will it start if you jump from the postive side of the sol to the small s post? think the black wire will go to the postive poat on the sol BUT THAT IS JUST A GUESS. Try having someone hold the ign in start and montarilry touch the black wire to the postive post. maybe someone with a wiring diagram can help.
 

bax

New Member
Electrical problem, 454 Chevy power at dash

Hi Nash, thanks for your input. Here is what I found out. By taking the solenoid out of the equation I was able to get everything to work. Turns out there are several different kinds of solenoids, and while they all look alike they are not. In my searching and my observations, I have dtermined that the solenoid can be cut from the system with no ill effects. It seems there are only two reasons for this solenoid. One, is to break the circuit from the car battery to the fuse panel eliminating any possiblilty of voltage leaks leaving you with a dead battery and two, to assist in the use of the Booster switch at the dash. By eliminating the solenoid, connecting the battery cables together (making a positive connection to the dash panelm fuse box, and the key switch) and by connecting the two purple wires together (completing the circuit to the starter)everything is then controled by the Key switch. What is lost is the Booster switch making it possible to use the house batteries as a booster to a dead car battery. Hey, I know how to use jumper cables. Thanks for you help. Also a big thanks to Mike who has really gone out of his way to help, thanks, to all Dan
 

C Nash

Senior Member
Electrical problem, 454 Chevy power at dash

Thanks for giving the update on the problem Dan. I should have thought to mention that the sol might be the wrong type and still look the same. Senior moment I suppose. having a lot of them lately. Wonder why :eek:
 
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