GBowman

What are the odds of both IAC's going bad within 3 hours of each other??? Reason I ask is that I recently replaced the dash panel so all wiring underneath was disconnected/reconnected. Soon after the dash work (say 2 hours run time) the Port side IAC went bad (melted the plastic part of the housing) and I got a 2 beep every 60 sec alarm which can be 100 different things but thank God I have the scanner. Easy fix...fast forward 3 hours over two weekends and the Starb side does same thing. I am 100% sure we got the wiring correct under dash but the timing of these has me wondering, I did change both batteries immed prior to the Starb IAC going bad but can't see that having any effect. Both IAC's had melted housings, maybe its just a coincidence??? I usually replace both of anything once one side goes bad as a precaution but didn't here, shame on me I guess.

BUP

iTrader: (9)

when the plastic melts you have problem as the IAC is running at higher duty cycles creating higher heat levels of the IAC itself. So hot that you can not touch it.

Adding info for both engines to have failed almost at the same timeframe sounds like possible lack or missed maintenance for the IAC system. Or possible voltage issue. Just saying and a word of heads up. There is a lot more to it than just changing the IAC's out.

Also 2 beeps every 60 secs is only for sensor and or sensor circuit related issues for ECM 555 and PCM 555 so its not as many as one would think.

GBowman

BUP-I did notice that the previous owner was running batt's on "Both" so parallel, do you think that could have something to do with it? I have always run ea engine on its dedicated batt and used "both" if one batt was down and immed switched back once both engines were running.
Thx

BUP

iTrader: (9)

Not seeing your wiring nor you battery system set up nor the battery selector switch (Perko or whatever brand) hard to say.

BUT have to add NEVER and I mean NEVER turn a battery switch when the engine is RUNNING at any rpm levels nor turn the engine off at the batter switch nor turn from battery 1 to 2 or both while the engine is running . NEVER do this period. . Even for carbs apps.. MPI even worse to do so.

speicher lane

The Medium and heavy Perko Selector's are a "Make-before-break" battery switch where you can select between batteries when running in any position other than "Off" - statement direct from PERKO... Switching to "off" when the engine(s) is/are running - well, you you went looking for the outcome.....