C3 Electrical Question

[Don Justham]

While working on my horn relay, with all of the wires unattached I turned the key over (forgot all was unattached). The ammeter (battery gauge) now reads all the way over to the right +40 with the car running. What have I done and what can I do to fix it? Thanks for the help.

[Jack H.]

Re: C3 Electrical Question

You PEGGED da sucka by creating a dead short to ground!

There are two alternatives to this scenario, one is good the other is not so good....

In the first case, you WRAPPED the pointer needle beyond it's frictional damping limits and it's a 50-50 shot you can recover. To attempt a recovery with the gauge in-dash, it's a matter of seeing IF you can 'coax' it back into its normal swing-excursion limits. Try starting the car and once the engine is running, repeatedly (BUT GENTLY) tap on the gauge/cluster. Hopefully, you can 'lift' the needle off its pegged position and normal electrical bias will return it to its proper pointing position. You may have to make multiple attempts (tapping here/there) to free the pointer needle....

If that doesn't accomplish the task, rather bad news... It's time to R&R (remove and re-install) the gauge). These were not high precision, jeweled movement instruments...they were 'el cheapo' needle bearing gauges.

Once the gauge is out of the instrument cluster, you can physically touch the pointer needle. If you haven't done excessive electrical or mechanical damage to the guage when you overloaded it, you can sometimes (now you're down to a 1 in 10 chance) 'free' the pointer needle by physically (CAREFULLY) moving it off extreme excursion and back into it's normal dymanic range.

The remaining possiblities aren't good.... It saw too much excessive excurion for too long a time period that you actually 'blew' the inductive windings of the guage. In this case, you'll free the pointer needle with your fingers, but it will refuse to respond properly when you re-apply it to the controlling circuit. The other catastrophic alternative is the gauge is electrically OK, but the abrupt and excessive overload crippled it mechanically (needle bearing is shot, Etc.). Both of these situations call for sending the gauge to a competent instrument repair shop (look for ads in NCRS Driveline magazine's Services' section)....