Electrical Issue - Idle

[Gunny]

1997 Galant ES 2.4 automatic

Yay. Finally got the IAC issue sorted. Everything has been fine for a few weeks.

Then, yesterday, the idle started drooping with the headlights on and a little more with brake pedal depressed.

Went through and checked all the obvious: cleaned and reseated ground points on the firewall, replaced terminal connectors on the battery, checked alternator connection. Battery and alternator are new within the last 7 or 8 months. The negative battery cable itself seemed a little corroded, so I cut off about 2 inches on the end and cleaned it best I could, but I'm sure it needs replacing.

So any ideas? I will stop on the way home today and have the alt/battery meter checked.

And how hard is it to replace that negative cable? Looks like probably the entire intake box and maybe even the fuse box will have to come out. I can't see where the other end hits the frame.

Thanks.

[tamim13]

I had a similar issue with the 8g and I thought it was electric too, but after changing my throttle body, IAC and TPS, it went away, so I would think it's your IAC again. Did you get a new IAC, or was it a used one? I believe the service manual has a way to test the voltage on the IAC.

[Gunny]

I had a similar issue with the 8g and I thought it was electric too, but after changing my throttle body, IAC and TPS, it went away, so I would think it's your IAC again. Did you get a new IAC, or was it a used one? I believe the service manual has a way to test the voltage on the IAC.

I hope that's not it, because it seems to adjust itself just fine when the A/C kicks in, raising the idle to offset the extra load.

It actually did this once before when the negative terminal got corroded. Cleaning everything up helped. Also, The negative cable seems to have corrosion in it even beyond where I cut.

Gonna try to replace that first before I go buying a new IAC. I just didn't want to have to gut the engine compartment to get at the otther end of the negative cable. Looks like at a minimum the fuse box and whole air intake box are going to have to come out.

Anyone done this?

[w/oarctic7g]

Cut the bad section off strip a little and use this cable splice it's quick, cheap, easy and almost foolproof.

http://www.oreillyauto.com/site/c/detail/SS00/08865/N0358.oap?ck=Search_N0358_-1_3106&pt=N0358&ppt=C0005

[Gunny]

Just to update. I replaced the ground cable down to where it bolts into the frame/body on the passenger side. I cleaned that connection up really well and then followed the ground wire on down to the transmission bolt and cleaned that connection as well. Also found that the swivel bolt for the alternator had come loose. Snugged everything back down and idle was rock solid at 850 last night and all the way to work this morning. Still a slight dip in the headlights when I hit the brakes but it only lasts a second before it compensates, so I guess that may be normal, especially on a rebuilt alternator.

Thanks for the suggestions, and man am I glad it wasn't the IAC this time around.

:icon_cool:

[Galanttuner10]

idle dips on all cars the more loads you add especially being an older vehicle. my new 2012 lancer does it. stop nit picking and messing with other things. dont like it raise the idle in park/ neutral to 1000 rpms. all my 7gs when auto in drive lights on etc idled at 600 and had dips etc. unless it stalls out consistently you are fine.

[Gunny]

idle dips on all cars the more loads you add especially being an older vehicle. my new 2012 lancer does it. stop nit picking and messing with other things. dont like it raise the idle in park/ neutral to 1000 rpms. all my 7gs when auto in drive lights on etc idled at 600 and had dips etc. unless it stalls out consistently you are fine.

Good to know. For mine though the lower the idle drops the rougher it idles. It doesn't stay smooth at all.

If it weren't such a gas saver on my commute vs the Hemi, I'd roll it out into the field and shoot holes in it.. lol