Crossflow suspected alternator problem

[Alan.gilford]

Hi, just wondered if anyone could point me in the right direction please.

Problem started on way back from Dunsfold in pouring rain with lights and wipers on, about 3 times car cut out after suddenly losing all power but as soon as switched off and back on ran fine.

Been fine since so I put it down to the rain.

Yesterday on the way back from Brands going through tunnel with lights on car lost all power so quickly turned off and restarted fine. (bit scary in Dartford tunnel)

Car is a 92 crossflow with weber alpha ECU 

I am thinking this probably points to an alternator issue as only seems to occur with an electrical drain like lights or wipers, any thoughts or advice would be welcome.

Thanks Alan

[Jonathan Kay]

1. Check all the relevant wires and connections that keep the ignition working: switch, battery, ECU, coil or equivalent, including earths. Visual inspection, wiggle, disconnect, clean, reconnect.
2. And the same for the alternator.
3. Measure the battery voltage at rest, minimum during cranking and at 3,000 rpm.

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When the car lost power what happened to the lights... unaffected, total failure, dimmed... ?

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Does the ignition warning light behave normally: on with the key, off as soon as the engine's running?

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Any recent work on the car?

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Do you have the appropriate wiring diagram?

Jonathan

[Stridey]

I had intermittent alternator probs early on in Crossflow ownership. Rain exacerbated it.

Do your wires go into a plug, or are the wires more exposed on the terminals? I found wiring the plug for the the 3 wires, then plugging it in with the wire clip to hold it firm protected the area more from the wet. It’s exposed down there!

[Alan.gilford]

Many thanks for the quick replies,

Voltages are 12.8 all turned off, 10.5 cranking and 13.3 at 3000 rpm.

Lights brighten and dim with engine revs when checking in garage so appears to be charging just not sure if that's enough  of a charge ?

When problem occurs not sure of lights behavior as was daylight the first time and panicking in tunnel the next time. although ignition warning light comes on and goes out correctly once restarted.

Will continue checking connections and I do have three separate connections down there that have plastic insulators on but feel very brittle due to heat from exhaust. I will try to remove and clean them up and look into replacing with the plug suggested.

I have recently changed headlight bulbs to uprated ones but that was after the problem first happened and no other work done to car other than oil and filter change.

I do not have a wiring diagram for the car so if there is one available it would be much appreciated.

Thanks Alan

[Jonathan Kay]

Please send me a Private Message with your email address and details of the Seven: model, year, engine etc.

Jonathan

[elie boone]

Also make sure the level in your battery is correct.

[OliverSedlacek]

A sudden loss of power is unlikely to be the alternator as the battery will keep the engine running even when the alternator is playing up (and your voltage measurements suggest the battery is healthy). Problems when raining would suggest the HT should be looked at. The most likely problem though is a dodgy wire somewhere, and I'd start with the earth between the engine and the chassis.

[Alan.gilford]

Thanks for all the tips and I think problem is resolved.

Checked all the earths I could find and I think it was the one on the front offside chassis upright, taken this one apart and cleaned and just been for a run with lights on and all seems fine :-)

Thanks again

Alan

[OliverSedlacek]

Glad it's sorted