Alternator Startup Delay
Guest
Posts: n/a
Alternator Startup Delay
Hello.
First post for me here.
I have a 1987 XJ6 named Caroline. Love her very much. Yet...she's quirky.
Have a little issue that I can't find the answer for. Maybe it's normal, maybe she's ill, I don't know.
When I turn her on, the alternator doesn't start delivering a charge until I'm down the road a little bit, usually when I hit the main road and the RPMs are raised.
Until then, her gauge sits at 10 volts, but when she "activates" the gauge goes to 13 and all is well, headlights brighten, the whole works.
Is this delay normal, or do I have some relay or something to replace.
Thanks for any info.
First post for me here.
I have a 1987 XJ6 named Caroline. Love her very much. Yet...she's quirky.
Have a little issue that I can't find the answer for. Maybe it's normal, maybe she's ill, I don't know.
When I turn her on, the alternator doesn't start delivering a charge until I'm down the road a little bit, usually when I hit the main road and the RPMs are raised.
Until then, her gauge sits at 10 volts, but when she "activates" the gauge goes to 13 and all is well, headlights brighten, the whole works.
Is this delay normal, or do I have some relay or something to replace.
Thanks for any info.
Joined: Mar 2008
Posts: 2,521
Likes: 71
From: Powell, Ohio U.S.A. 43065
RE: Alternator Startup Delay
There is a single terminal lead (18 gauge, it's a small wire)that plugs into the back of your alternator...it's an "exciter" wire, and if that lead is open circuit the alternator won't start charging until engine RPM's are at least 2000. Check connection at alternator.
Joined: Mar 2008
Posts: 2,521
Likes: 71
From: Powell, Ohio U.S.A. 43065
RE: Alternator Startup Delay
The capacitor is for radio supression, and has nothing to do with nothing. There is a brown/ black color coded wire with a single Lucar female spade connector: that plugs onto a male spade terminal for the alternator field winding, on the back of the alternator. If you follow it back to source, it is routed behind the A/C compressor, tywrapped to the fuel return pipe at the front of the cylinder head (along with the A/C compressor clutch feed wire and the leads to the air pump diverter valve), through the engine wiring harness to CF3 (right bulkhead multiplug), to the battery warning light on the dash.
Veteran Member
Joined: Mar 2008
Posts: 25,525
Likes: 11,716
From: Pacific Northwest USA
RE: Alternator Startup Delay
After you've checked the exciter wire etc to make sure the charging circuit operates don't be too surprised if your voltmeter is still slow to react. Every Ser III I've driven has a lazy voltmeter. Sorta like a morning sickness type of thing 
Joined: Mar 2008
Posts: 2,521
Likes: 71
From: Powell, Ohio U.S.A. 43065
RE: Alternator Startup Delay
The"headlights brighten" comment in the original post precludes a voltmeter inaccuracy.
Trending Topics
Veteran Member
Joined: Mar 2008
Posts: 25,525
Likes: 11,716
From: Pacific Northwest USA
RE: Alternator Startup Delay
ORIGINAL: JagtechOhio
The"headlights brighten" comment in the original post precludes a voltmeter inaccuracy.
The"headlights brighten" comment in the original post precludes a voltmeter inaccuracy.
Good point....I missed that !
Cheers
DD
Thread
Thread Starter
Forum
Replies
Last Post
Chuck Schexnayder
XJ XJ6 / XJ8 / XJR ( X350 & X358 )
33
Oct 24, 2015 10:20 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)