HelmutGTI 5 1 Cars Posted July 17, 2018 My car, which I have renovated, got a new battery yesterday. I switched on the ignition and noticed that I could not hear the fuel pump prime. Measured the current at the plug to the pump 0.3V, then measured the connector to the fuel relay, also there where only 0.3-0.4V I tested the pump directly to 12V from the battery and it worked fine. Nor do I think it's wrong with the fuel relay (tachymetric relay) when the power in is to too low. Where should I start looking? // Also I have 3 dissconected cables in the fuse box, see picture, any idea? Kind Regards Patrik Share this post Link to post Share on other sites
HelmutGTI 5 1 Cars Posted July 17, 2018 Hmm, just read this... And it confused me. According to DamirGTI the phase 1.5 or phase 2 has their tachymetric relays in an other place I sourced mine. Mine is located on the side of the washer fluid resorvoir n the engine bay. Im not shure if mine is a 1,5 or a ph2 modell but its defenitaly not a ph1 modell? Share this post Link to post Share on other sites
jackherer 543 Posted July 17, 2018 I think the tachymetric relay was still in the engine bay of very early phase 1.5 models. What year is your car? If there is no power at the tachymetric relay I would be looking at the ignition switch and any alarm or immobiliser that might be fitted. Share this post Link to post Share on other sites
HelmutGTI 5 1 Cars Posted July 17, 2018 1 hour ago, jackherer said: I think the tachymetric relay was still in the engine bay of very early phase 1.5 models. What year is your car? If there is no power at the tachymetric relay I would be looking at the ignition switch and any alarm or immobiliser that might be fitted. My car is from 1990. It doesent got any alarm, or immobiliser either? Share this post Link to post Share on other sites
jackherer 543 Posted July 17, 2018 A 1990 should definitely have the tachymetric relay in the cabin next to the ECU. It was still in the engine bay until late 1987/early 1988 I think. If power isn't getting to the relay start at the ignition switch, check for power there then work back towards the relay. If it's been dismantled for renovation it might just be a plug not fully seated or something. Share this post Link to post Share on other sites
HelmutGTI 5 1 Cars Posted July 17, 2018 31 minutes ago, jackherer said: A 1990 should definitely have the tachymetric relay in the cabin next to the ECU. It was still in the engine bay until late 1987/early 1988 I think. If power isn't getting to the relay start at the ignition switch, check for power there then work back towards the relay. If it's been dismantled for renovation it might just be a plug not fully seated or something. Ok I will check. This is what I have in the engine companrtment thinking it’s my fuel relay. Oddly it says Hella on it? Could it be a relay for high beam lights then? Share this post Link to post Share on other sites
welshpug 1,622 Posted July 17, 2018 as your car is in Scandinavia is it anything unusual like a Catalytic converter equipped low compression engine or a Motronic engine? Share this post Link to post Share on other sites
welshpug 1,622 Posted July 17, 2018 that image of the AFM confirms it is Motronic, which IIRC used two separate standard square relays not a tachymetric relay? the wiring to the relay in your hand are not large enough to be ignition and fuel pump wiring. Share this post Link to post Share on other sites
HelmutGTI 5 1 Cars Posted July 17, 2018 Found this... Share this post Link to post Share on other sites
HelmutGTI 5 1 Cars Posted July 17, 2018 Also I have this! Share this post Link to post Share on other sites
HelmutGTI 5 1 Cars Posted July 17, 2018 One small thing, since I have no oil in the engine I don’t want to crank it. I just put the ignition to 2nd level. Share this post Link to post Share on other sites
Tom Fenton 1,525 Posted July 17, 2018 I think you are chasing a fault that isn’t there. Put oil in try and start it. 2 1 Share this post Link to post Share on other sites
HelmutGTI 5 1 Cars Posted July 18, 2018 13 hours ago, Tom Fenton said: I think you are chasing a fault that isn’t there. Put oil in try and start it. YES! Start to think so to. I´ll leave the fuel pump untill startup try. But has any one any idea where this 3 cables goes to? Share this post Link to post Share on other sites
Ryan 99 Posted July 18, 2018 AFAIK Motronic ECUs don't prime the fuel pump. A lot of the documentation floating around the internet says they do, but it's wrong. 1 Share this post Link to post Share on other sites
jackherer 543 Posted July 18, 2018 It is normal to have some disconnected plugs like that, they may be either for diagnostics or for optional equipment you don't have. Can you see any wire numbers? On right hand drive UK 205 GTIs there is often a disconnected yellow wire behind the instrument cluster that is only connected on models with carburettors and manual chokes, it activates the choke light on the dashboard. That might be what at least one of your connectors is for, but as your car is probably left hand drive I am not sure. Share this post Link to post Share on other sites