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Replaced fuel pump, now all electrical is dead?!

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Ajdial31 Aaron Dial
Phoenix, Arizona, USA   USA
1972 MG MGB
Got the fuel pump replaced with a brand new solid state SU pump and it fits perfectly. I had disconnected the battery in order to give myself more visibility and room to work. However, once I replaced the battery, none of the electrical will come on when the key is turned. I checked the fuses and they're fine. The battery is new and was working just fine last week. What the...?

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bencii Ben Colpitts
Mansfield, Ohio, USA   USA
1966 MG MGB
Start by checking voltage at the battery? Do you own a meter?

ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
Put battery back in properly
Made sure you didn't knock ground cable off body mount
Checked charge 12.7v

"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"

"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972

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bencii Ben Colpitts
Mansfield, Ohio, USA   USA
1966 MG MGB
When hooking up the battery make sure the negative post is attached securely to the body. Sometimes that short cable gets replaced with a red cable and owners think it is the positive cable.

gofastandfalldown Avatar
gofastandfalldown Glen Horne
Edmonton, Alberta, Canada   CAN
1970 MG MGB MkII "Miss Pandora Moneypit"
Nothing works when you turn the key?? What about when you don't turn the key? i.e. headlights, hazards, etc. etc. Is it totally dead or only some dead?

Donthuis Avatar
Donthuis Don van Riet
Rijswijk, ZH, Netherlands   NLD
Buy a test lamp if you do not yet own one and check with it the fuse positions one by one, starting on the lowest, which should be hot all the time.
The one but lowest comes up with the ignition switched on and the two top ones are linked to the light switch. Of course one side on the box is unfused, the other fused.

My guess is you somehow missed reconnecting the battery in a proper way.

BTW the pump line is normally unfused, so the connection should light up in sync with the one but lowest fuse position. I myself put a floating fuse before this white line to the back under the hood

PS Once resolved a tip for the next time: there is no need to disconect the battery for anything not linked to "always on" battery lines, the ignition switch sees to that eye rolling smiley
And even a lot of "hot" battery lines can be isolated by temporarily removing the bottom fuse of course (headlights excepted)

Edited 1 time(s). Last edit at 2017-03-21 03:47 AM by Donthuis.

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