Author Topic: Need help with rewire (batt + and alt. wireing) 1980 Turbo trans am  (Read 477 times)

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Offline jcurrieta

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got this car few weeks ago,,, someone hacked up the loom harness going to the alternator. I also noticed the car isnt charging as well. No wires were hooked to the rear post on the alt. There was also some melted wires so i cut them all out and am replacing them, they basically had all red wires connected, im not sure if the wires burnt on something hot or they got too hot from electrical issue and being hooked up wrong. I have Haynes manual but wire diagram isnt too good. Please someone tell me were too hook this wires too.

Alt
-larger red wire from plug (where do i hook this to harness) ?
-black wire from plug is going to harness (this was not cut) OK
-rear post on alt (nothing hooked to it, guessing its my no charging issue) ?

Harness
-Thicker red wire (where do i hook this)?
-thinner red wire (where do i hook this)?
-thinner red w/black stripe wire (where do i hook this)?
-black wire (uncut going to alt. plug) OK
2 green wires (uncut going to sensors/emissions) OK

Battery + side
-someone added a red wire to go to harness.. is this bad or causing more issues?
'80 Turbo Trans Am Pace Car
'81 Trans Am (Y84 recreation) "SOLD"
'96 Trans Am LT1 "SOLD"
'82 Firebird (Trans am clone) "SOLD"
'81 Firebird (1st car) "Wrote off"
'98 Trans Am Ws6 Ram Air "SOLD"

Offline Stringer

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Re: Need help with rewire (batt + and alt. wireing) 1980 Turbo trans am
« Reply #1 on: June 22, 2018, 07:46:51 PM »
I am not too sure if a 1980 is different than a 1979....but here is a basic overview of the engine bay wiring. I have also attached a crude drawing to help.

  • There should be a ground strap at the back of the engine that runs to the firewall.
  • The negative ground from the battery gets hooked to the engine.  There should be a stud near number 1 cylinder to mount it to.
  • The positive from the battery goes directly to the starter.
  • On the starter, on the same terminal as the positive cable, should be two red 10 gauge wires that run up form the starter along the firewall, to the bulk head, and into the interior.  I think both go to the ignition key with one being the main power wire.
  • There should also be a red (?) 12 gauge wire going to the starter solenoid that also runs up to the bulk head, into the interior and to the ignition.
  • There should be two 12 gauge wires running from the alternator connecting to the main power wire (the same wire coming from the starter) making a connection back at the firewall.  FYI --- Be sure to put a 40-50 amp fuse link in the main power wire after the connection from the alternator, else you run the risk of a fire if the starter grounds out or if you max out the amps when activating other systems due to other wiring problems or bypassed relays.
  • There should be one 12 gauge pink(?) wire that runs from the bulk head to the distributor which connects to the ignition coil on top of the distributor.
  • I believe this wire is also connected to the ignition key. The rest of the wires connected to the distributor come from the ignition module inside the distributor itself and connect to the ignition coil on top the distributor.
  • The tac is a tan wire that is hooked directly to the distributor at the ignition coil as well. (it is not shown on my wiring diagram but connects to the terminal next to the power wire on the ignition coil)
  • There is also the wire to the temperature gage (green?) and oil sending unit (blue?) also not shown in the diagram. Those are in the same loom with the altenator and connect to the bulk head on the firewall.

Hope this helps

Offline jcurrieta

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Re: Need help with rewire (batt + and alt. wireing) 1980 Turbo trans am
« Reply #2 on: June 24, 2018, 03:21:08 PM »
yes I got all that thank you.... I still see only 2 wires going to your alt diagram. I have 3 red wires to hook somewhere... im guessing alt. but I need to know what wires are on the alternator post and plug.
'80 Turbo Trans Am Pace Car
'81 Trans Am (Y84 recreation) "SOLD"
'96 Trans Am LT1 "SOLD"
'82 Firebird (Trans am clone) "SOLD"
'81 Firebird (1st car) "Wrote off"
'98 Trans Am Ws6 Ram Air "SOLD"