Starter not turning

patkeefe · 07-09-2019, 08:53 AM

The short story is when I turn the key, the starter does not engage...no clicking, no dimming of lights, nothing.

Long version is, everything was ok UNTIL I TOUCHED SOMETHING. I relocated the battery from the smugglers box back to its original location, and I changed the spark plugs. Car is a 78 SC, turbo. As such, it has EFI, and nothing is anything like it was when it left the factory. 14 pin connector is long gone. I figured maybe I knocked a wire loose; can't find anything. I have battery voltage at the starter. I have continuity from 50 at the switch to the 50 terminal at the starter. I assume the 50 terminal simply provides power to the starter solenoid, and it internally makes a switch to rotate the started motor. I put in a new ignition switch I had lying around; no change.

Can I simply jump out 50 to 30 to test the started solenoid? I am thinking I may have a starter issue. Again, everything was OK, UNTIL I TOUCHED SOMETHING.

The last time I engaged the starter, it worked, thankfully. That was last week, leaving the paint shop.

timmy2 · timmy2's Garage

Yes, jump across to engage solenoid to see if if it works

timmy2 · timmy2's Garage

Check for 12 v from start switch when in start position at short yellow wire coming out from 6 pin connector on trunk side of firewall.

patkeefe · 07-09-2019, 09:18 AM

Thanks Dennis. I will check for voltage there, on the trunk side.

T77911S · 07-09-2019, 09:35 AM

use a test light.
compare the light from the battery voltage to the starter signal. they should be the same

it takes a lot of current to pull in the solenoid. you can have 12v but there may not be enough current due to resistance somewhere along the line.

how is the ground connection at the front,
is it a good connection between the battery and the body,

patkeefe · 11:56 AM

Jumped across the solenoid engages the starter and it turns normally Ground connections are OK I’m going to run a jumper from terminal 50 at the switch to terminal 50 at discharge her and see if it changes anythingj.

Edit: Works fine when I jump it

proporsche · proporsche's Garage

the starter is fine...start with the basics...the main problem is usually the ground straps between the trans.and the body.Loosen the 13mm wrench nut clean it and see. Let us know..
this one...........
Ivan

timmy2 · timmy2's Garage

Pat, replied to your PM.
Give me a call.

cabmandone · cabmandone's Garage

Had something similar to my BIL's car while vising him. Ended up being the yellow wire that goes to the starter solenoid coming loose in the connector in the engine compartment.

T77911S · 07-09-2019, 07:03 PM

Quote:

Originally Posted by proporsche

the starter is fine...start with the basics...the main problem is usually the ground straps between the trans.and the body.Loosen the 13mm wrench nut clean it and see. Let us know..
this one...........
Ivan

if he jumped from term 50 to 30 and it worked fine, then its not the ground strap.

timmy2 · timmy2's Garage

After talking with Pat, per his testing, it is a fault in the wiring from front to back of car or in the ignition switch harness. He doesn’t have time to fix it for a while. Other priorities.

cabmandone · cabmandone's Garage

Did he test the yellow wire that goes from the plug in the engine compartment to the starter solenoid? I'd start by pulling the plug in the engine bay and testing continuity from plug to solenoid end then check voltage up to that point.