Menu toggle

Electrical woes!

R

rholt

New member
I've recently replaced the fuel tank in my 1976 Carrera 3.0, along with the sender unit, but not the pump. I've been tackling a number of other jobs as well, so it's been a while ( about 12 months)since the battery was connected and the engine last ran. Anyway, I put the battery back in place, but on connecting the earth terminal the fuel pump immediately started to run. The ignition wasn't switched on and I didn't check what else did or didn't work. I've tried a couple of times and as soon as i touch the negative terminal with the earth strap the pump starts running. Wondered if anyone had any ideas as to what I may have done to cause this, or what I can check to try to diagnose the problem.
Many thanks,
Richard
 
Been on hols, so only just read your "cri de coeur"; if you haven't sorted it yet, here's what I would do (although mine is an '81 SC):
Firstly, remove the fuel pump relay (under the bonnet, nearside, without going and looking at mine, I think it is the red relay nearest the front of the car, the identification is moulded onto the Fuse/Relay cover). this should remove the power and stop the pump running.
If I remember, my Targa has an identical relay in the engine compartment under the cover on the nearside, which is also red (i.e. 25amp for the heated rear screen) so if you have one too, try swapping this for the fuel pump to see if it makes any difference.
Also, Fuse 16 feeds the relay, so removing it should stop the pump.
With the K-Jetronic, the airflow sensor contact switch operates the relay, but I think it needs the ignition turned on to operate.
The live feed to the starter solenoid also goes to the pump relay to ensure the pump runs when the key is turned, before the airflow sensor/relay cuts in. There would need a short to live in the ignition switch but then the starter would run as well as the pump, so this sounds unlikely.
Good luck.
Philip
 
Hello Philip,
Many thanks for your reply. I'm away myself at the moment so haven't had a chance to do any more to the car. I'll try your advice when I get back and let you know how I get on.
Thanks again,
Richard
 
You must log in or register to reply here.

Posts made and opinions expressed are those of the individual forum members

Use of the Forum is subject to the Terms and Conditions

Disclaimer

The opinions expressed on this site are not necessarily those of the Club, who shall have no liability in respect of them or the accuracy of the content. The Club assumes no responsibility for any effects arising from errors or omissions.

Porsche Club Great Britain gives no warranties, guarantees or assurances and makes no representations or recommendations regarding any goods or services advertised on this site. It is the responsibility of visitors to satisfy themselves that goods and/or services supplied by any advertiser are bona fide and in no instance can the Porsche Club Great Britain be held responsible.

When responding to advertisements please ensure that you satisfy yourself of any applicable call charges on numbers not prefixed by usual "landline" STD Codes. Information can be obtained from the operator or the white pages. Before giving out ANY information regarding cars, or any other items for sale, please satisfy yourself that any potential purchaser is bona fide.

Directors of the Board of Porsche Club GB, Club Office Staff, Register Secretaries and Regional Organisers are often requested by Club members to provide information on matters connected with their cars and other matters referred to in the Club Rules. Such information, advice and assistance provided by such persons is given in good faith and is based on the personal experience and knowledge of the individual concerned.

Neither Porsche Club GB, nor any of the aforementioned, shall be under any liability in respect of any such information, advice or assistance given to members. Members are advised to consult qualified specialists for information, advice and assistance on matters connected with their cars at all times.

Porsche
Lockton
Pirelli
Officially approved
Oracle Finance
WEX Esso
Collecting Cars
Archant Dialogue
Back
Top