flanders

30V AC is very high and would cause serious problems, are you sure it was not 30mV (0.03V)?
Show a picture on your multimeter if you are unsure.

captb

Reading up on it more, I'm quite sure its a problem with my multimeter. Apparently, this is a common problem with cheap multimeters, where they can't truly read the ACV but rather the peak or RMS. This is one of the threads i read (https://www.garagejournal.com/forum/...p/t-75551.html)

I got mine a few years ago from walmart, so this makes sense. As a test i measured an AAA battery. On DC I get 1.6V but on AC i am getting 3.0V, which is obviously incorrect.

I'll confirm this tomorrow on a good working car.

captb

Ok, I was able to get my hands on a proper multimeter (fluke brand). I believe my ACV is less than 0.1.

The multimeter only has one decimal place (probably not meant for automotive use). Not connected to anything it reads 0.2V, and when I hook it up to the alternator it still shows 0.2V. so I assume the voltage result is less than 0.1V.

If this is the case I believe all my issues are solved. Thank you all for the help!

flanders

Yes sounds like everything is good to go

captb

Checking back in. The car has been running really good, my idle has improved so much in fact that most of the time i think i've stalled.

However, I am still having some bugs unfortunately.
- Every once in a while, the battery light and parking light would flash for just a split second. It usually happens when I let go of the throttle and only occurs occasionally.
- Also, my check engine light does not come on however I am still getting code p0325 (knock sensor). Again, i don't notice any misfiring, rough idle, and no CEL.

I just wanted to confirm that the next step is replacing the knock sensor. I tried to feel around and it seems to be intact but since the headgasket was just replaced there is a chance the mechanic accidentally knocked it to hard (no pun intended).

***Edit***
I just had another thought. While i was diagnosing the alternator/battery I also took out the old viper alarm system. One of the things I did was crimp the main ignition wire together as it was previously bypassed by the alarm system. To make it easier for myself I left portions of the viper alarm wires and spliced those together.. so in essence i had 3 crimp connectors [ -------OEM Ignition wire------ (crimp) -------- wire------- (crimp)------ wire----- (crimp)------ OEM ignition wire----------]. Would that cause enough resistance to cause the odd behavior?

I'll try to solder and shrink wrap this connection and see if i have any luck.

engifineer

It is possible you have a bad connection with the crimps. I would get that fixed up first since you know there can be a potential issue there. I suspect you have some issues around the cluster if it is not displaying a CEL when you know it has one. When you first turn on the key, but do not start the car, does the CEL come on then, or just never at all?

captb

You are absolutely correct. The check engine light does not turn on at startup.

There are a few things that come to mind.
- the wiring for the alarm used lots of in-line spices. The ones that cut the plastic and wedge the wire. Is it possible that one of these wires were cut in the process?
- When i removed the alarm there were 2 wires that i cut that was connected directly to the pin connector and only fed into the alarm unit, nothing else. I assumed these were empty slots used to get a 12v source. These wires looked like they were bigger than all the other oem wires as well. Did these need to be connected to anything? see photo below. this is the connector above all the fuses, just under the start button.
- The only mod to the electronics that I am aware of is the air pump delete. Could this cause any of these symptoms?
- my bluetooth obd2 device still does not pick up any voltage from the control module. is this related to the no check engine light?

the check engine light was working for sure prior to the headgasket replacement and i trust my mechanic that did the work. so i doubt the bulb was simply removed.

I might just get a new ecu to try out. I'm starting to run out of ideas though.



PS: just realized that replacing the ecu is not a simple swap. Have to get the keys reprogrammed as well.

engifineer

Well the electrical diagrams are scattered in various sections of the shop manual. I am adding the pages for the 00-03 gauge cluster here. This can maybe help you check to see if all of the wiring is properly connected to the cluster. Not sure how much help it will be given the wiring is chopped up elsewhere, but hopefully having this will help trace back to it. The diagrams for everything else are broken down more by purpose rather than location in the car.

Unfortunately, the AP1 does not have a gauge cluster self diagnostic mode like the AP2 does or I could share that. The AP2 has this so you can try to determine if the cluster is working properly.

captb

Thanks for the sections in the manual. Comparing to other startups looks like the check engine, maintenance required, and SRS lights do not turn on at startup.

Other than the ECU i dont see anything that links these together.

Also, i was able to confirm that the wires connected to the alarm are indeed blank slots. so not that.

_valtsu_

Looks like only light you mentioned that is controlled by the ecu is "malfunction indicator lamp MIL". SRS light is controlled by SRS unit and maintenance required light is controlled by gauge clusters driving circuit.

My guess is that your gauge cluster is somehow not working properly.

If I understood correctly Obd devices are working properly, but you are just getting error of voltage from ecu? This could be normal. Looks like there is only one 12V pin on obd connector and it's powered from battery.