Charging issue with Check engine light

[lawsoncl]

the Renix era ones, will show a huge voltage drop when you turn up the fan, but it's a quirk of the voltmeter circuit.

I think that voltage drop on the Renix is real. It's just the cumulative drop through the wiring, ignition switch, C101 connector, ground, etc. Ideally though you want the voltage measured at the battery and not at the instrument panel like the Renix dash gauge does. So yeah, the dash gauge sucks and just gives you a rough idea of whether you have a problem (like turning on the a/c makes it drop way down)

 

[Matthew Currie]

I think that voltage drop on the Renix is real. It's just the cumulative drop through the wiring, ignition switch, C101 connector, ground, etc. Ideally though you want the voltage measured at the battery and not at the instrument panel like the Renix dash gauge does. So yeah, the dash gauge sucks and just gives you a rough idea of whether you have a problem (like turning on the a/c makes it drop way down)

The voltage drop is real, but very localized and by itself it has nothing to do with the charging system, which is my point. Once you're used to it you can always monitor it for unusual readings, but on my 87, for example, 9 volts was a "usual" reading for fan on high and all other systems working correctly. If it had suddenly dropped to 6, I'd have been worried, but when it said 9, I knew I was getting the usual 14 at the battery.

 

[SanDiegoOverland]

Ok, just an update. Swapped in a new (rebuilt w/ new slip ring, brushes, bearings, terminal posts, copper windings, etc.) alternator from a nice-looking local electric's guy that my mechanic recommended. He was very helpful and had one sitting all pretty and shiney for me when I came to pick it up.

Spent last night swapping it in, and though it was more involved than I thought it would be, just like any other install on my Cherokee, it was very doable.

I test fired it last night and drove it to work this morning. Same result:

1. No check engine light
2. Volts come up to 13.8-14.1 immediately with no funkyness.
3. lights are way brighter and engine has a different, healthier note.

So far so good! yay!


P.S. My mechanic is John at Elite Auto in Santee off of bradley. The alternator shop is Broadway Auto electric. Rick is the gent I talked to there.

 

[SanDiegoOverland]

Ok, just an update. Swapped in a new (rebuilt w/ new slip ring, brushes, bearings, terminal posts, copper windings, etc.) alternator from a nice-looking local electric's guy that my mechanic recommended. He was very helpful and had one sitting all pretty and shiney for me when I came to pick it up.

Spent last night swapping it in, and though it was more involved than I thought it would be, just like any other install on my Cherokee, it was very doable.

I test fired it last night and drove it to work this morning. Same result:

1. No check engine light
2. Volts come up to 13.8-14.1 immediately with no funkyness.
3. lights are way brighter and engine has a different, healthier note.

So far so good! yay!


P.S. My mechanic is John at Elite Auto in Santee off of bradley. The alternator shop is Broadway Auto electric. Rick is the gent I talked to there.

boy oh boy does this post sound gay. I wasn't intending to sound like the "guy" was nice looking, only to say that the shop was very modern/welcoming/tidy. I could see why my mechanic recommended them.

that is all. haha!

P.s. no offense to gay people. Just wanted to be clear.

 

[austinaubinoe]

hahaha That was funny.


Just wanted to add that you can get Grand cherokee alternators, etc rebuilt at autozone for about $120 W/ a $30 core. My stock 2000 is 117amp, so even that could be an upgrade.

How much did the rebuild end up costing you?

Oh and another tip: If you ever go through mud, flush the alt with a bottle of water. Sand and dirt kill alternators very fast!

 

[SanDiegoOverland]

hahaha That was funny.


Just wanted to add that you can get Grand cherokee alternators, etc rebuilt at autozone for about $120 W/ a $30 core. My stock 2000 is 117amp, so even that could be an upgrade.

How much did the rebuild end up costing you?

Oh and another tip: If you ever go through mud, flush the alt with a bottle of water. Sand and dirt kill alternators very fast!

it was 120 + 20 core charge. Bout the same as chinese crap at Vatozone and a rebuilt "?" brand at the dealer actually. This was for a freshly built Denso unit. Very shiny.

good tip on the flush. :thumbup:

 

[sbxj]

P.s. no offense to gay people. Just wanted to be clear.

no worries here, gays don't drive XJ's...only Liberty's, Patriots and Commanders

 

[joe_peters]

Don't ask, don't tell.