Need Help: Engine swaps/ No Start/electrical issue.. (Long story)

[rollercoaster]

Been around here for a-while, don’t post much, but now need help from the brain trust.

I recently bought a project car that has obviously led an interesting life. It’s a 1987 Turbo, the previous owner blew the motor, then sold the engine and trans with the intent on buying another, he then sold the car.

The next owner swapped in a modified 3.2 and did one of the worst harness installs I’ve ever seen.. (see pics) It ran and he drove it several years in this manner until a missed-shift grenaded his motor. He couldn’t afford the rebuild the time and traded the motor for a 79 3.0 and had the parts on hand to build a short stroke 3.2 Engine. Motor was built and partially installed when p/o slacked off and the project just sat.
Between cash and some horse trading I acquired the car a few months ago and with the help of a knowledgeable Porsche friend finished the install. However we now have a no-start issue.

1. The engine is fine, turns over by hand w/ no problems. This is an electrical issue that is keeping the starter motor from turning after the solenoid engages the starter gear.

2. Battery, and three different starters are all good. Starters were bench tested prior to install and each kick-out and spins as it should. All ground connections to the care are clean and making contact. Ignition switch has been tested and is good. All other electrics appear to wrk as they should.

3. When the key is turned, the starter solenoid kicks out as it should but the starter motor does not turn. A quick test with a test light at the lug on the starter shows bright when key turned on, then dim when as starter gear kicks out and starter-motor “does-not-turn.”

So, does anybody have any idea what the heck is going on… can anyone provide a picture of the wiring on the back-side of an 87 Turbo fuse box?

Thanks guys!

[rollercoaster]

[redridge]

The circuit maybe complete (enough to turn on the solenoid), but those wire nuts may not be enough to pass enough current to turnover an engine. I would get rid of those nuts and have a more robust method to connect those wires...

[onboost]

Sounds like something is cutting the voltage to the starter.. Looks like most of the mess is centered around the 1st two relays from the right side..

If I'm not mistaken, those would be fuel pump relays on an 87 Turbo chassis.. not sure they would control any current to the starter.

You might want to look for the thick yellow wire in the main harness just under mess pictured and try to test the current there when turning the key.

Good luck!

[bazar01]

The starter circuit is just a +12V thru a 2 or 1 gauge cable, a ground path through the starter body and a control wire for the solenoid. Since you are getting control voltage to solenoid through ignition switch (solenoid kicks out), either you are missing good contacts on the +12V and ground, or battery is weak.