Running a mk1 alternator on a mk2

[FD3Si]

Morning all,
Anyone have any info about this swap and the wiring needed? Long story short I want to run the mk1 alt on a 1998 mk2 1.6.

It seems like I may need to swap pulleys, but I can't find much about the wiring?

Any help much appreciated

[beeblebrox]

Can't offer any advice about the wiring, but you shouldn't have to swap the pulleys AFAIK.

Early Mk1 1.6s had a v-groove pulley+belt but the 1.8 Mk1 onwards use a multi-ribbed design instead.

[FD3Si]

Ah cool, so 1.6 MK1 should see me on that front, ta

Now just bracket checking and wiring! Pretty sure that the mounting is the same as when people swap the MK2 block into a mk1 they just swap the alternator over AFAIK.

[Richyvrlimited]

What ECU?

The MK1 alternator is internally regulated, the MK2 regulator is regulated by the ECU.

The MK2 ECU won't take kindly to not being able to regulate the alternator.

[beeblebrox]

FD3Si said:

Ah cool, so 1.6 MK1 should see me on that front, ta

Now just bracket checking and wiring! Pretty sure that the mounting is the same as when people swap the MK2 block into a mk1 they just swap the alternator over AFAIK.

No - the 1.6 Mk1 was the only one with a v-groove belt. All Mk2s use a multi-ribbed design.

[FD3Si]

Sorry, misunderstood. I get it now, Ta.

The ecu is stock mk2, and that's the root of the issue. It's a very early mk2 Eunos 1.6, no ABS. Basically its overcharging horrifically. I changed the alternator but to no avail.
As you say, the regulator circuit is buried in the ecu. So I'd Luke to Rey another ecu, but the only one I found was asking for ridiculous amounts of money. I was hoping to run a mk1 alt and just using a 12v live for the regulator feed.

[Richyvrlimited]

If your that way inclined you could just build an external regulator and cut out the stock ECU's regulator.

It's a pretty simple circuit if your interested.

[NeoVR]

FD3Si said:

Sorry, misunderstood. I get it now, Ta.

The ecu is stock mk2, and that's the root of the issue. It's a very early mk2 Eunos 1.6, no ABS. Basically its overcharging horrifically. I changed the alternator but to no avail.
As you say, the regulator circuit is buried in the ecu. So I'd Luke to Rey another ecu, but the only one I found was asking for ridiculous amounts of money. I was hoping to run a mk1 alt and just using a 12v live for the regulator feed.

Have you checked the grounds? if your handy with a multimeter it might be worth trying to find out what voltage the ecu is "seeing" by prodding the 12v pins. Ive heard the main ground that goes to the PPF at the back of the car can corrode away causing various issues.

I have an Adaptronic ECU running off the stock harness and have noticed it sees about 1v less than battery voltage. 13.9v at the ecu when running is almost 15v at the battery.. im assuming the same 1v "drop" is what the stock ECU is seeing.