Carpokes Porsche Forum

Hi all,

I have an 83 944. It has been off the road for a long while, so we have been slowly recommissioning it over the past year or so. Initially once we got it going after doing the belts, etc., it started fine. However, it has become harder to start - kind of had to hold the key in the start position and then the starter would engage. I replaced the ignition switch suspecting that, but no change in symptoms. Now on most occasions, it won't even engage the starter - dash lights will dim, but no starter turnover. If I lay underneath it and short the terminals on the starter, it will start fine.

Now my main suspect here is a ground situation between the ignition switch and the starter. Is there a decent diagram of where the main grounds are on the 944 to check? Any other hints?

Thanks in advance!

Just adding MY input is to clean ALL THE GROUND locations at least once a year, I’ve included that as basic maintenance on our 40 plus yr old vehicles.. It also allows me to inspect the wiring for age cracks in the insulation too…

Which starter terminals are you shorting? If you’re shorting the main battery-cable terminal to the small solenoid-wire terminal and it cranks normally, that points to the starter-control circuit -- i.e., power to the ignition switch, the switch itself, its connector, the wiring to the solenoid, etc.

I'd (safely) probe the small solenoid terminal with a multimeter while turning the key to start and see if it is getting solid battery voltage. If not, work backwards toward the battery until you find the drop.

I don't have the current flow diagrams for your car. For my similar car...

There is no 'ground' for the ignition switch. I'm all-in on following the guidance for annual all-grounds cleaning, but there is no ground function involved for the ignition switch itself. An incredible number of odd gremlins are magically solved with that ground and terminal cleaning exercise. On older cars, especially ones that have been stored with moisture inside, this gets done as a first PM step when chasing any gremlins. At least in my own limited experience.

Do you hear the starter relay click as you cycle the key to 'start' position when no crank? Do you hear the starter solenoid itself, with maybe a half-hearted movement and noise?

IF you have an automatic gearbox, there is a "neutral safety switch" function where the ground side of the starter relay coil passes through that switch to gearbox ground when the gear selector is in Neutral or Park position. The switch itself plus the terminals and wire connections are suspect. Try cycling the gear selector through all positions a few times, and see if that makes a difference. Sometimes the movement is sufficient to 'wipe' oxidation from the internal contact surfaces.

I don't know if the 944 demands that the clutch pedal is down for cranking on manual gearbox cars. That switch would be in place of the neutral safety switch in the ground side of the relay coil circuit instead of the neutral safety switch. The local ground for that switch has the same importance as the one for the neutral safety switch ground.

928 cars with manual gearbox have a copper jumper in the starter relay socket, and pass the 50 contact on the switch through that jumper to the 50 terminal in the solenoid. No clutch pedal position interlock function.

Else there's a common 53B SPST relay in the starter relay socket. Replace that relay.

If none of this seems to cure or at least help you diagnose your no-crank symptom, next steps go to the starter relay socket, looking for coil ground, and coil voltage with the key in start position. Then at battery voltage at the 30 terminal, and a solid low ohms continuity reading through to the solenoid coil including the wire and lug connection to the 50 pin on the solenoid itself.

HTH!