Alternator Vauxhall 2 L HPC

[Reiver]

The alt. looks to be original as it has the same wiring as the diagram in the build book.  It is a Motorola  9rc 7042, obviously a Euro unit and strangely it comes up as often used on boats.... it is a big heavy lump.  The issue I have (it is working) is replacement when/if the time comes..... also I wouldn't mind a smaller more efficient unit.

The wiring is strange to me...4 wires from the unit.  I've never seen that kind of wiring before...one or two wires being the norm.

The real puzzler is the wire to the fuse box.

Has anyone replaced this booger with something else and perhaps a description of your wiring.  Thanks.  The pic is an exact copy of the Cat 7 2L carburetor type wiring diagram 

alternators.pdf

Edited May 17 by Reiver

[MV8]

The warning lamp and voltage sensing are normally the same lead. A single, heavy gauge lead is normal instead of two, thinner leads.

 

[Reiver]

Electricity is magic to me....how would you wire up a one wire unit?  A two?  It appears you'd lose the ign warning light.

[MV8]

No need to lose the warning lamp. A standard, oem ALT can be wired to be "one-wire". If there is no clearance to the header issue, I suggest a similar sized case replacement versus a mini. The GM CS series ALTs are very good but any domestic oem, internal regulator ALT that fits the bracket and belt would be fine. They can have up to four small wires, usually three, but only one is required and it can be for a warning lamp. The geo metro ALT (an oem mini, low output) is popular.

 

Post a pic of the ALT installed. Header clearance?Tensioner or slotted arm? Vee or flat 4 or 6 groove belt? Distance between pivot center and center of adjustment slot if equipped? 

Edited May 18 by MV8

[Reiver]

the header is on the driver/opposite side...for a good pic I'd have to remove one of the carbs.  V belt.  I'll remove the front and get a pic but it will not show the wiring.

[MV8]

Never mind. I missed the part where it is still working so I assumed it was coming off. The hard part if finding one that will bolt-on and for that you will probably need to take it off to measure. Also check the clocking of the attachment lugs (usually on the front half of the case). The rear half with the electrical connections can be reclocked relative to the lugs if needed for wiring clearance to the block. Pulleys can usually be swapped for different belt types.

[CarlB]

I tried one of the GM CS alternators and the case broke. Most race cars use Denso alternators. That is what I have now and have had good luck

[Reiver]

I'll take a look but wonder if 55 amps is enough... what motor are you running?

[MV8]

I assume you are talking to Carl about his motor.

CS alts are not crack prone.

Alts are rated for temporary max output, not continuous, so if you don't have efi and a high output cooling fan, 55amps is probably ok, but not optimal if you try to drive with a dead batt after a jump start. Any other time it is sufficient and the alt life should be ok.