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Posted by: Sprout Aug 12 2019, 01:28 PM

A little guidance, please...I've replaced the ignition switch in my '73 1.7 FI twice now with Meistersatz parts, and the car is dead again. Has only been started a couple dozen times between these two switches. When I turn the key, I have lights on the dash and can hear the fuel pump engage, but the engine does not crank. Battery is at 12.5 and just installed a reman Bosch starter/solenoid. It can be push-started.

From what I've read the switches seem to fail fairly often, but only starting the car a dozen times per switch seems pretty ridiculous. Are the genuine Porsche switches that much better?

Do you think I could have something shorting out the switch? The 914 key is the only thing on my keyring, so I know it's not an extra weight problem.

When it's running, it runs great!

Posted by: Superhawk996 Aug 12 2019, 01:36 PM

China is a funny place.

I've seen amazing high quality come out of that place and I'd seen absolute crap.

I ordered a "914" replacement from a site I've honestly forgotten since it was such a low dollar part ($12 ish?). Didn't even fit. I "made it" fit for purposes of proving out my starting system for a neighborhood drive before I disassembled my car.

It will get replaced with Porsche part when my rustoration is completed.

Posted by: 76-914 Aug 12 2019, 01:51 PM

I bought a used OEM switch from @Bdstone and keep it in my glovebox. Heard too many bad things about the aftermarket switches. You might check the voltage on the yellow wire going to the starter solenoid. Disconnect it and turn the switch to read. Does tapping on the starter with a hammer make it work. Or does jumping the terminals on the solenoid make it work?

Posted by: nditiz1 Aug 12 2019, 02:37 PM

I have 2 new in box ones for sale. Can't tell if they are german, but they are cheap. I had a push button start to bypass sending the current over the switch. Sometimes I would forget and use the switch, but never had any issues.

Posted by: framos914 Aug 12 2019, 02:45 PM

Had same problem, went through a few switches. Problem turned out to be an intermittent short on the fuel pump wire, had a bare spot that would sometimes rub against metal. Found it when it completely shorted out, not sure why the fuse didn't go before that.

Posted by: sixnotfour Aug 12 2019, 02:46 PM

is the yellow wire under pass seat , bypass mode,,connected directly together..


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Posted by: Mark Henry Aug 12 2019, 03:25 PM

My ford solenoid mod takes the load off of the ignition switch. I don't know if it helps with the aftermarket switches.
Link in my signature below.

Posted by: orthobiz Aug 12 2019, 04:35 PM

I did a thread on this in the Parts Vault:

http://www.914world.com/bbs2/index.php?showtopic=109146&hl=

Paul

Posted by: RoadGlue Aug 12 2019, 07:39 PM

I had the exact same problem with my '74. Sometimes it would crank and rather frequently you'd hear the pump run but the starter wouldn't engage. I pulled the ignition switch, and wouldn't ya know it, the back of the housing was cracked.

Purchased a new switch, installed it, seemed to work fine and then shortly after had the same issue. Pulled it out, and hey, it's slightly cracked again. WTF.

Installed a second new switch and it had the same behavior. This time I decided to hunt around and found that if I wiggled the relays under the passenger seat while holding the switch to "START" I could get it to crank.

Do exactly what "sixnotfour" posted. Bypass all the seatbelt interconnect BS and I bet you'll be on your way. If not, it could be a bad starter solenoid. I'd say ignore any cracks in the ign switch housing for now until you confirm nothing else is causing the issue.

Posted by: Amphicar770 Aug 12 2019, 08:01 PM

Does having a gear reduction starter reduce the load on the switch versus the old Bosch units?

Posted by: Chris914n6 Aug 12 2019, 08:48 PM

How worn is the cam that turns the switch?

Mine wore enough that it wouldn't turn the switch enough to connect the start tab.

I've used a few Uro switches with the white 'quality control' dot that are quality. Replaced the Uro green dot that was so bad I made a demo video.

Posted by: Mark Henry Aug 13 2019, 06:57 PM

I'm not sure, I should measure it on my 3.0 10.5 CR /6 conversion. I just left my solenoid on but thought to myself the same question.
It sure spins the engine faster, even with my small lawn tractor size Odyssey 680 battery.

Posted by: 914Toy Aug 13 2019, 07:17 PM

Unless you are maintaining originality, consider installing a push button start switch, which takes the torque off the key switch and minimizes it’s failure.

Posted by: Sprout Aug 14 2019, 05:11 PM

Thank you, everyone, for the replies and ideas! I had been reading quite a few threads in various places about things to try. The starter and solenoid are good. I don’t have the seat belt sensor under the passenger seat, since it’s a ‘73.

I called the local Porsche dealer to see if they happened to have a switch in stock since Porsche Classic is offering more parts all the time. They didn’t have it in stock, but ordered it and was the same price as online vendors, plus I don’t have to pay shipping. To my surprise, they are working on classic Porsches as well! I never expected them to be interested in touching a 914.

Posted by: sixnotfour Aug 14 2019, 06:25 PM

is that confirmed

Posted by: Mblizzard Aug 14 2019, 07:38 PM

It is just a fact of time and entropy that the efficiency of the starting system degrades over time. With a car that was designed to last 10 or less years there is no question that the resistance in the system has increased dramatically in 50 years.

Go only with the German part you can still get at the dealer and install either the Ford or modern relay to increase the effectiveness of an old and tired system.

Posted by: Sprout Aug 19 2019, 03:36 PM

Well, easy come, easy go. I picked up my OEM ignition switch from the local dealership. Parts guy was SUPER nice! There were several posters of 914s on the walls around the dealership. Great to see that!

Then, I tried to talk to a service guy about working on it, since the parts guy was confident they would. He shut me down immediately and said there was nobody there who could work on a 914, only old 911s. Wasn't the technology pretty much the same in '73? I asked if they were planning to learn, since Porsche is taking a direct interest in classics, and he said "not at your expense."

I looked down at the Originale parts book, the new Christophorus magazine with 914s on the cover, and the 914 poster hanging over his head...and left.

At least I have a local source for parts if needed!

Posted by: Superhawk996 Aug 19 2019, 04:09 PM

Welcome to the modern version of Porsche

Translated you 914 Guys are cheap SOBs and we don’t want your kind of business.

Posted by: Highland Aug 20 2019, 11:44 AM

Since I'm a cheap 914 SOB I just wanted to make sure "genuine" ignition switches are the only way to go. Looks like there's roughly a 5 times price difference compared to the aftermarket switches. (I do plan on using the relay.)

My switch was working but I found this when I took it out.