1985 CRX Si, with MSII board
The CRX voltage regulator is internal, and it apparently is an early example of pcm controlled voltage regulators. Now, no pcm, only MS.
Had it tuned and running before a voltage spike burned out U5.
Anyone have a suggestion for a simple external voltage regulator solution?
voltage regulator- alternator
Forum rules
Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0).
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0).
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Re: voltage regulator- alternator
Are you saying the alternator was controlled by the original engine ECU? I know some newish cars do this, but didn't know it was around in '85. If so, the easiest way would be to fit a conventional alternator. They're so cheap new it's not worth messing about.
FWIW, MS is pretty well protected from voltage spikes and it would be some spike to destroy U5.
FWIW, MS is pretty well protected from voltage spikes and it would be some spike to destroy U5.
Dave P, London UK.
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
Re: voltage regulator- alternator
Yup, I didn't think a car that old would have a computer controlled voltage regulator either.
Thanks to Megalog, I know exactly how big the voltage spike was- 25.7. The IC voltage regulator on the board is rated to 26.
Think I can return it for not meeting spec? :>
Thanks to Megalog, I know exactly how big the voltage spike was- 25.7. The IC voltage regulator on the board is rated to 26.
Think I can return it for not meeting spec? :>
-
Matt Cramer
- Super Squirter
- Posts: 2951
- Joined: Sat Jul 03, 2004 11:35 am
Re: voltage regulator- alternator
Some of the Hondas had a simple switched voltage - you grounded the pin that ran to the ECU to make the voltage drop down to around 12 volts; you'd get normal voltage without it. If the ECU had a full-blown voltage regulator in it, though, you could use an external voltage regulator from a different source. A good application to ask for at most parts stores is a '76 Dodge Dart - it has a fairly cheap regulator that works with most externally regulated alternators.
Re: voltage regulator- alternator
Thanks, Matt. I checked out the Dodge piece. Not only is it cheap and easily available, so is a wiring harness connector for it.