Starter Motor issues

[decgraham]

Hi All,

Well, I've had this annoying issue with my car for a few years now. In the summer here when it's hot if I take the car for a run and then do a few stop starts I come back to the car and it won't start. I then have to leave it for half an hour, return and it will start. I thought that it was a starter motor problem, after all the starter motor is 27 years old! So, I bought a new one and fitted it. (Porsche instructions on how to do it attached) What a job, it took me 6 ½ hours to remove it and get it back in. However, I learnt a lot. Getting to the 2 bolts is a nightmare, the top one is by touch and feel, I had my eyes closed trying to find the bolt. Pretty much the same on the bottom bolt but that was so tight, I thought I'd never slacken it off, there is so little space, but with a ½" drive ratchet I finally got it loose. Once I removed the starter motor, which again is not easy as there so little space even when I dropped the transmission as far as it would go. This was further than the 10mm recommended by Porsche, I supported it on a jack but it was actually sitting on a cross member. Fitting was a real pain, once I lined up the starter motor, I needed a third hand to try and get a bolt in but no joy. I persevered for a least a couple of hours trying to wedge it with a piece of wood so I could get a bolt in but the motor kept dropping out. I then remembered reading on Rennlist about hugging the gearbox (on a manual) so I tried the same and went over the top of the gear box from the RHS as I lay on my back with my feet facing the back of the car. Doing this I found that I could feel the top bolt hole so I was able to support the motor with my left hand and get the top bolt in with my right. It was then a piece of cake to fit the bottom bolt. After a couple of hours struggling, I got it bolted back in within 10 minutes. If only I'd remembered that earlier. I then connected the wires and tried the starter...... nothing but a clicking solenoid when I turned the key. I gave up at that stage but tried the old starter motor by connecting it to another battery with jumper leads and then jumped the power cable to the light cable and the motor turned over perfectly. I though I'd bought a duff 'new" motor. A good nights sleep and this morning I thought I'd check the voltage at the main terminal on the new starter motor, 12.6 volts as it should be, grounding was good too. I then passed a wire up to the motor main terminal and jumped the motor to the light connector as I did with the old motor. The motor turned over like a dream. I repeated the jump about 7 or 8 times and it turned over every time. However, on the key... only the solenoid click.

I now believe that there was nothing wrong with my original starter motor but it is a problem with the ignition switch. The reason I say this is because if I wiggle the key in the switch and turn, it would suddenly turn the engine over and start. I switched it off and tried again, all good, tried a third time and the old solenoid click. Through out the day I tried it at various times, I was doing an oil and filter change, and sometimes it would start and sometimes no joy just the click.

So, my learned forum members, has anyone got an opinion as to whether I'm right or what you might think is the problem? If it is the ignition switch how do I get it out? Any advice, suggestions greatly appreciated.

ATB

 

[Tycho]

I have suffered with lazy starting when the car was warm/hot for several years, no problems from cold. Embarrassing when the car would not start after filling up. I was never stuck but it sometimes took 4 to 6 attempts to start & I did not want to risk this in the future. A new starter motor fitted in September seems to have cured this, I hope I have not now jinxed the car – will find out next Spring as I have just put it on SORN.

 

[A993LAD]

I'm not sure exactly how the ignition switch works. But if you are hearing the solenoid click every time you turn the key then doesn't that mean it's doing it's job and the problem is more likely to be at the starter motor end.

I thought the ignition key simply put a live signal through to the solenoid which then fired up the main power to the starter motor.

But if you want to to pull the ignition switch out to check it it's relatively simple.

The plastic ring around the bit where you put the key in can simply be undone anti-clockwise and removed. Behind it are two Allen bolts and if you undo those the ignition switch is completely free to remove and pull out the bottom of the dash.

It takes a bit of manoeuvring because there is a 6-in bar sticking out the side of the ignition barrel into the steering column to provide the steering lock. But given your experience fitting the starter motor I think removing and replacing the ignition switch will be easy in comparison.

You can pull ignition switch down with all of the wiring connected to it. But I found it easier to reach up first and pull off the electrical connecting block on the back of the switch which just pushes on and pulls off.

I also found it easier to replace the ignition switch and bolt it into place first and then plug the electrical connector block on afterwards.

With the ignition switch removed and the connector block dangling down beneath the dash you can plug the ignition switch back on to the connector block and test it to your hearts content.

I have tried to attach a picture of the complete switch plus the connector block which I removed to work on the the alarm immobiliser connections recently. Actually looking at these pics I'm wondering if it's supposed to have a bolt holding the long arm bit into the steering column?? Mine certainly isn't locked into the steering column but maybe the bolt fell out or someone never replaced it.

 

[Les Richards]

...I've had issues with starters over the past couple of years and reported on here. Currently on a replacement under warranty from ECP and so far seems OK.

The mechanic who services the car said the problem is normally the solenoid but that's not to say you shouldn't check all the other possible likely trouble spots. I toyed with changing the ignition switch but was put off by the cost - if it wasn't that - and the implied difficulty.

 

[decgraham]

Hi A993LAD,

Thanks for your reply :thumb: I understand what you are saying about the ignition switch but when I jump the starter terminals the motor turns over every time. When I do this am I not simply by-passing the ignition switch?

There is a large heavy black wire which comes directly from the battery and then a few red wires of various thickness that connect to the large terminal number 30. There is then a small yellow wire that attaches to the small terminal number 50. It is these 2 that I have jumped to get the starter to spin, and as I have said this process made the starter spin every time. (see attached)

Thanks for the removal advice, the pictures are great too. When you mention the bolt are you saying that your steering lock doesn't work due to the bolt missing or is it just a retaining bolt?

As you have done this your advice is invaluable :thumb:

ATB

I've posted this again as a reply, some how it went as a new post :?: :?:

 

[A993LAD]

Thanks for the removal advice, the pictures are great too. When you mention the bolt are you saying that your steering lock doesn't work due to the bolt missing or is it just a retaining bolt?

yes my steering lock works fine. The steering lock shaft locates in the steering column housing and has a lock that slides in and out of the end. Which I guess locates in a slot in the steering shaft itself. When you turn the key the lock retracts.

I've removed my lock/ign switch a few times and the only thing that holds it in place are the 2 allen bolts either side of the key slot. Once you've pushed the steering lock shaft bit into the steering column it can't really fall out once the allen bolts are tightened back up.

The only reason I thought there might be a bolt at the steering column end was this diagram I found (part 12)....

I'll take a look at mine again this morning to see if there is a hole for a bolt?

Also, don't worry about getting the circular electrical connector block wrongly positioned as the half moon shaped hole in the middle makes it easy to correcty locate when replacing it.

 

[A993LAD]

well I'll be damned, I just went and had a look under the dash and I do have a bolt that goes into the steering lock bit of the ign lock. You can see it out of focus on the RH side of the attached pic.

So I thought, better tighten that up then. Which I did. And then my steering lock stopped working! When I loosened it back down to the position it was in, the steering lock worked again.

So if you do decide tro drop the ignition lock out, my suggestion is just undo the 2 allen bolts on the front face and see if it will drop out without touching this bolt. It looks like it might be for adjusting the alignment in the steering column rather than fastening the lock itself.

 

[decgraham]

Thanks again for the feedback A993LAD :thumb: I've just had a look at my ignition switch and I have shear bolts holding the unit in. Also do you need to remove the VDO unit to get to the back of the switch?

ATB

 

[A993LAD]

Wonder why you have shear bolts? How do you remove those? Perhaps mine once had them and my 5mm allen bolts are replacements?

No I've always managed to remove it around the VDO, although access would be easier if you dropped it down. I could only see the VDO bolt on one side so left it in place.

 

[decgraham]

Hi A993LAD, Shear bolts are quite common on key switches etc. Basically makes it difficult for a thief to rip out your ignition switch quickly and steal your car. If I need to remove the lock I'll just drill them out and fit allen bolts like you. I'll have a closer look at the VDO unit, when I took the picture it looked pretty tight up there. On Rennlist they suggest just unscrewing the 2 screws out of ignition switch and removing it without removing the lock. Its seems you need a short stubby screwdriver and probably the hands of a child with the strength of superman

ATB

 

[A993LAD]

Right ignore all my assertions that removing this is easy!!!

Read this instead.............

http://forums.pelicanparts.com/pors...orum/958346-993-ignition-tumbler-removal.html

I'm guessing mine must have been removed once and then 3 normal bolts used instead.

The original installation seems to be 3 sheer bolts being installed. The 2 you can see being hard to drill out and the 3rd one (in the steering column) nigh on impossible.

My new suggestion for what it's worth is remove just the ignition switch but leave all of the lock mechanism and steering lock in place.

You should be able to pull the electric connector off the back. Then undo 2 screws (red arrow) to split the switch from the lock at the join (black arrow).

I've never done this and as my lock/switch is back in the car I can't easily see if it's doable.

Don't go trying to drill the sheer bolts though.

 

[A993LAD]

You got there before my post. Sounds like a plan

 

[decgraham]

Now I know why they say on Rennlist just to remove the switch mechanism

On the plus side it can't be any more difficult than removing the starter motor in the first place.... that was, as I said, difficult :evil:

ATB

 

[decgraham]

The saga continues,

I did a continuity test between the battery and the starter motor this morning and got a reading of 0.008 ohms with the meter probes together it reads 0.000 ohms so I don't believe it's a earth issue. I then checked the 12v supply at the motor and got a reading of 12.49 volts so all good there. I then run a separate earth cable from the battery to the starter motor, when I tried to start the car ... the same old click, click. I believe I've ruled out all the possibilities and it does in deed point to the switch or the wiring.

I wanted to double check the immobiliser so I cancelled the immobiliser on my key fob and turned the key to the run position. I then got under the car and jumped terminal 30 and 50, the car started up immediately and ran like a Swiss watch.

I have looked at the wiring diagram (see attached)and you'll see that terminal 50 goes all the way back to the ignition switch but passes through a connector X3 in the engine compartment and X28 on the steering column.

As terminal 30 has a +12v supply I believe it can only be terminal 50 wires or the ignition switch connection. I've attached a few pictures of the reading etc, along with my new 993 starting tool....it does the job

I'm thinking or running 2 wires up to the engine compartment from T50 and T30 and adding a switch so I can just start the car from the engine compartment until I fix the problem. A little Heath Robinson but it would work, as needs must

ATB

 

[A993LAD]

The saga continues,

I have looked at the wiring diagram (see attached)and you'll see that terminal 50 goes all the way back to the ignition switch but passes through a connector X3 in the engine compartment and X28 on the steering column.

ATB

Is the wire at terminal 50 the same colour all the way through to the ignition switch?

I would be tempted to pull the connector plug off the back of the ign switch, fix a wire into the contact in the switch that goes to terminal 50 and then run that wire round the car and connect it to terminal 50. Then push the connector plug back onto the ignition switch and try turning the key to start it.

If it works you'll know there is a break in the wire somewhere and start tracking it along it's route. with 2 connectors on the path it should help isolate the break point.

I had to do similar when I had a problem with my front oil cooler fan. ToreB helped identify the likely wire that was broken. We proved the case by joining a new wire into the plug at the CCU and running it right to the end point. With this temporary jump wire the fan worked as it should. Then I just had to track the break in the original wire and patch it across. Interesting your wire runs through 2 connectors as the break in mine was discovered at a big connector under the bonnet. the offending wire had broken off the solder joint at the connector.

Good luck.