ISIS, digidash, and Ricardo starter

I've emailed Jay to get his thoughts, but does anybody here have an ISIS, digidash, and a Ricardo transaxle?

I'm running into an unusual quirk in that if I crank the engine (to check for/build oil pressure, not to start), the second i push the starter button and the starter beings to crank, my digidash resets itself (ie., turns itself off then back on). No blown fuses or anything of that nature. It doesn't continually reset itself if I hold the starter down, just whenever I first push the starter. Other accessories (e.g., lighting if on) get a hair dimmer, but do not turn off or on.

Does anybody here have that combo and ran into this (or alternatively, have the above combo and had no issues)? No other electrical gremlins, but this unusual bug I'm trying to sort through.

Alex, it's resetting itself most likely due to low voltage from the cranking event. You should be sure that the cables from your battery are big enough (you did do the resistance calculation when you selected cables, right?), that you have adequate grounds of the same cable size on all loads, especially the starter, and that you have sufficient cranking power in the battery.

I would agree with Will. Most likely there is a threshold there in the digidash where if the voltage drops below X volts, it will re-set. I have a radar detector in one of my vehicles that does the same thing. Sometimes you can start the car and the radar detector will not re-set, and sometimes it does. If the engine is cold, it almost always resets.....if it's only been shut off for a few minutes and starts right up with little cranking, the detector will not reset. It's not losing power......it's just that power temporarily dips just low enough on occasion to reset it.

P-nut said:

Alex, it's resetting itself most likely due to low voltage from the cranking event. You should be sure that the cables from your battery are big enough (you did do the resistance calculation when you selected cables, right?), that you have adequate grounds of the same cable size on all loads, especially the starter, and that you have sufficient cranking power in the battery.

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2ga cable from battery to battery cut-off switch. 2ga cable from cut-off switch to starter, using heavy duty lugs.

2ga frame ground. 2x 2ga engine grounds (on heads), 1x 2ga ground on the starter case

Battery is in the rear of the car, not front, so 2ga should be sufficient.

I havn't checked voltage drop at the battery yet.

I'm using a group 51 battery, which is 500 CCA, 625 CA.

I spoke w/ Jay and John (digidash) and they both said what you and Shane said. Now trying to think if there's anything I can do about it, other than live with a quirk.

I don't run the ISIS but my Digidash never does that. I have the battery in the rear but have 2 ga. wires running to the dash for a master disconnect and back to the starter/engine. That is about 20 feet of wire!

EFNFAST said:

Now trying to think if there's anything I can do about it, other than live with a quirk.

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If all else fails, you might try a Dickfer. [ame=http://www.youtube.com/watch?v=eB8sG4smWbo]Spies Like Us - Whats a Dickfer? Chevy Chase & Dan Aykroyd - YouTube[/ame]

Does the ISIS disable other circuits during cranking like a lot of OEM's do

Simple answer, hehe - charge the battery fuller. It was only about 75% charged and I figured good enough, it wasn't

Let it sit on the tender overnight, fully charged, cranked the engine and no issues, yaaaay.

Since I'm using such a small battery I replaced my test lead acid one with an Optima...it has another 50 cca and provides all the amp right away (instead of having to ramp up like a lead acid), so every little bit helps.

But at least it was something simple and stupid ... I was hoping like hell it wasn't something in my wiring because as far as I could tell I had done it right. So basically, battery idiocy aside, this is the 2nd car I've wired up where everything worked 110% perfectly on the first try, thanks to ISIS/I^2 (I2 being the predecessor to ISIS) ... another one will definately be going in my 917 :thumbsup:

Even if I choose to 'restomod' my friend's 66 Mustang Coupe, I think I'd ditch the entire loom and replace it with ISIS... It might be expensive but I hear nothing but good things about it, the simplicity and the features that can be programmed into it.

Incase anybody is wondering, the smallest battery you can probably get away with in an efi slc with no frills (e.g., radio, etc...) is going to be an AGM group 51(or 51r) (450 cca, 575ca)

It fires up the car perfectly with no low voltage issues.

My test battery was a group 51 lead-acid battery (450 cca, 520ca). Even 100% charged the digidash would blip off and reset itself when cranking the engine. If the battery dropped to about 70% charged I couldn't start the car (fuel pump would die when hitting the starter).

So yea, AGM group 51/51r is probably the smallest/lightest I would go with (AGM also doesn't have to "ramp" up and has all the amps available right away, so that's another plus for it)