Battery Cutoff for Early C4

[Joe C.]

Any recommendations?
I have not seen the knife switch style. Is it available and/or feasible?
What sort of bypass is suggested to power computer, clock, radio preset memory, and other devices?
Thanks in advance.
Joe

[Bill M.]

Re: Battery Cutoff for Early C4

Joe:

I have a Wirth 20128 that is supposed to work on my '92. I haven't installed it yet. All I do now is unbolt the cable.

Don't know about by-pass.

Bill

[Joe C.]

Re: Battery Cutoff for Early C4

Joe:

I have a Wirth 20128 that is supposed to work on my '92. I haven't installed it yet. All I do now is unbolt the cable.

Don't know about by-pass.

Bill

THANKS Bill,

That's what I needed. Now, look at
SIDE MOUNT WITH FUSED BYPASS
#20310

on the following page:http://www.wirthco.com/pdf/Battery%20Switches.pdf

the 20311 fused bypass is sold separately, and will work with the 20128 knife switch. All it is, is a standard 15 ATO fuse, in a fuse holder, soldered to 10" 12 ga wire. No "magic".................it prevents memory loss of devices, but will NOT prevent battery drain due to a "hidden" light that is remaining lit. If you don't mind having your PCM suffer amnesia, with relearning with every disconnect, then there's no point in using the bypass, since you can drain your battery if a bulb is "on" somewhere.

Joe

[Joe C.]

Re: Battery Cutoff for Early C4

Hi Joe.

The 1985 uses a one-year-only ECM, MAF sensor, and PROM. The MAF is extremely expensive, compared to later years, and the ECM is NLA at any price.

Over the years, I've never really had trouble with ECM re-learning, or starting after battery disconnects, rundowns, or replacements. I took the car "through the NCRS system", where the cutoff was used numerous times on the judging field to keep from discharging the battery.

Last October, the car was judged at a Chapter event. The cutoff was used during judging. When I went to start the car to leave the event, it was really cantankerous, ran crappy, and just wasn't happy. I shut it off, and re-started it, and drove it away with no further issues.

I have no idea what the 'problem' was, but I am now being very careful about disconnecting the battery, or allowing the ECM to 'de-power' again. I do NOT want to take chances with 24 year old electronics that are no longer available. At the recent Lake Tahoe Regional, I did not disconnect the battery, or allow it to be run down during a Founder Opps check. The car ran perfectly for 1003 miles, more than it's been driven in the last 15 years.

I would highly recommend the fused bypass, to protect against ECM issues. The interior lights will still illuminate, and the battery can still run down, but it will not crank, which will pass muster with the Fire Marshal for indoor shows.

Looking forward to seeing you in San Jose.

Regards,
Dave

Thanks Dave...........
I have never used a battery disconnect on my '85, and have never benefited from any bonus points attached therefrom, in bringing the car through the NCRS "system". I had no real intention of ever using one. At previous indoor events, I have always simply disconnected the negative terminal at the battery, with unremarkable consequences. However, at this time I must maintain constant battery voltage to power electronics that must be maintained on-board. I must also satisfy the fire marshal at the Convention Center in San Jose, so the switch must finally be installed. I look forward to seeing you, also.

[Bill M.]

Re: Battery Cutoff for Early C4

THANKS Bill,

That's what I needed. Now, look at
SIDE MOUNT WITH FUSED BYPASS
#20310

on the following page:http://www.wirthco.com/pdf/Battery%20Switches.pdf

the 20311 fused bypass is sold separately, and will work with the 20128 knife switch. All it is, is a standard 15 ATO fuse, in a fuse holder, soldered to 10" 12 ga wire. No "magic".................it prevents memory loss of devices, but will NOT prevent battery drain due to a "hidden" light that is remaining lit. If you don't mind having your PCM suffer amnesia, with relearning with every disconnect, then there's no point in using the bypass, since you can drain your battery if a bulb is "on" somewhere.

Joe

Thanks, Joe.

Bill