Moonshine

So for several months now, my battery light has been on. My voltage meter never gets below the "R" on 'normal'. So get this. At an idle, my voltage will be down between the "O" and the "R". At this time the battery light will go away. With higher RPM's, say driving down the highway at 2400 RPM my voltage will be between the "R" and the "M". At this time the battery light will be on. Thoughts?

Secondly, upon first startup of the day, my coolant/fan light will come one for in the thereabouts of ninety seconds and a reciprocating squeaking will sound. Equivalent with the RPM of the engine. Approximately one squeak per revolution. Water pump? Thoughts?

Last but surely not least. My IAC valve is sticky. Thoughts on a delete against a new valve?

Thanks for your help.

PS. 1998 Cobra 70k miles.

MU71L4710N

batt light is more than likely your alternator.

not sure.

deleting the IAC? i didnt think you could delete the IAC??? you can delete the EGR, the IAC is what "adjusts" your idle and ive never heard of anyone deleting it.

Moonshine

Well...my decision to 'wait and see' clearly showed me that it was in fact NOT the alternator. It's seems as if the car thinks there is TOO MUCH voltage? This is odd. I replaced the alternator about two years ago.

You may be correct on the IAC. Would simply cleaning it solve the issue? It seems all too common to purchase another.

uberstang1

With a tune I beleive you can delete the IAC I remember seeing an article on it as well as a block off plate for it.

MU71L4710N

no. ford has stated the IAC is not to be cleaned. cleaning it usually helps, but is only a temporary fix. to completely fix a bad iac, it must be replaced.


and as far as the batt light:
https://mustangforums.com/forum/4-6l...-light-on.html

cliffys post.

JRad405

When you figure it out let me know. I have this squealing sound, that only happens in the winter and I always thought it was the alternator just doing something weird because it is cold out.

It goes away after warm up. Does your squealing sound do the same?

Markus989

I put in my HID's in last christmas and my battery light comes on intermittenly pretty much with no ryme or reason now. Sometimes just cruising, full throttle, idling ****s weird but its been happenin for a year and so far no consequences other than it being absurdly annoying. Ive checked my alternator 3 times under diff conditions, load tested the battery and i keep a close eye on the battery light and nothing out of the ordinary...