The ECU could've been replaced with a rebuilt or used one and not necessarily a bran new one. Even if it was, being new does guarantee that it'll last any length of time, so it could still be bad.

The voltage regulator is built into the ECU and it's an all or nothing replacement.

Try contacting this seller on eBay and see if he'll ship to the UK. Current price is $75.00 US.
http://cgi.ebay.com/ebaymotors/1993-...mZ110479156959

 

I have read on this forum, or another, that the external voltage regulator, must be hooked up with the battery disconnected. It must be grounded to the firewall and fully connected before reattaching the battery cables, or it will fry and cause an overvoltage situation.

In your photo, that does look like a voltage regulator, and the case is not grounded, as far as I can see.

 

hmm thanks for pointing that out. This is something I was wondering about because I moved it as the original location was directly in a 'drip-zone' (see first photo!). It's got open sides, direct to circuitry, which you cant see in the photo. It was screwed into the panel under the hood - you can see the screw hole in the first photo, to the left of the rusty screw at top. It probably was a poor ground as the paint was mostly intact...

I'll disconnect it tomorrow and see if the voltage changes at all.

Alloro, I'll also get in touch with ebay guy - thanks!!!

Wilbo

 

ok, curiosity got the better of me, I've taken off the VR and here's the inside of it.



There's no evidence of frying, I've tested resistance across the + and - and it's about 90 ohms. It's the same resistance between + and F (field?) and when the arm is pulled in towards the coil this connects + to F.

So if this is working, I should see that little arm flicking back and forth when the engine is running?

Should the original field connection (from the PCM) on the alternator be disconnected when using this thing?

oh, and it doesn't look like the case needs grounding as it doesn't connect to anything inside? but should I do this anyway!?

 

Sorry, my knowledge of voltage regulators ends with the little I've read on how they are to be installed. Alloro, help the man out.

 

Yes sir!

Some mechanical regulators are 3-wire and some are 4-wire, with the 4th wire being the case. The easiest way to know is to check for continuity from the case to various points within the (disconnected) regulator. This being a non-factory regulator, I would also be hard pressed to come up with information beyond the basis.

 

I did this test and there's no continuity from case to anywhere so I think I'm safe not to ground

I'll keep you posted guys, but I'm going to try to get a new PCM asap.

thanks