Painless (but not for me) wiring harness issues • The Dodge Challenger Message Board

by **Adrian Worman** » 07 Aug 2010 16:23

Hi mates,
Big problems with my car day before Euronats

, need a little bit of help to point me in the right direction.Was out cruising around the public racetrack that is Milton Keynes, everything going lovely then a loud pop from the dash, all electric systems dead.
Inspection at side of road revealed the 70amp maxifuse in the Painless harness had blown quite spectacularly, requiring a lot of effort to remove cos it was in small peices!
I replaceed the 70amp fuse, and looked at the fuse box, I had blown the coil,wiper and gauge fuses, also the heater fan motor stopped. Replaced all the fuses and got power to most everything except ignition circuit, but the wiper circuit blows its fuse as soon as the ign switch is in run position, even with both the motor and the switch disconnected.
Heres the worrying bit, while my car was in my nephews workshop waiting for its mot, it was worked upon by a probably well meaning mate of ours who decided to rewire the charging circuit, cos he thought the alternator was'nt getting power.
He wired the voltage regulator to the ign feed of the ecu ( a chrome box 4pin) and the alt. feild wire straight to the alternator, so the alt. did'nt appear to go to the regulator at any point. I 've rewired it back to Painless wiring diagram but I can't get any voltage to the alt.feld terminals, and the ballast resistor is getting vrey hot after just a few seconds. Looks gruesome doe'nt it?
I've e-mailed Painless tech and got a reply but the guy did'nt really do much more than tell me to start looking at the charging circuit first.
I know I've got an awful lot of work to do, a lot of the system components may have failed as well, I can't imagine I'm entirely right, but I've inspected all my terminals, checked for frayed or damaged wires etc and found nothing.
So, any thoghts me old pals :?:

I'm still smilin' tho, probably been desensitized by Dodge fever :roll:

by **dave-r** » 07 Aug 2010 18:30

To blow that fuse you need one hell of a short circuit. You need to start from scratch and check everything in the charging and ignition circuits.

Make sure the alternator output or field circuit does not have a short.

Don't worry about the ballast resistor. It is supposed to get hot.

by **Adrian Worman** » 07 Aug 2010 19:23

I've been doing some testing at the fuse box and I've found that the same power feed for the wiper is the same as for the alternator volt reg and field, so I left the battery lead connected to the alt but removed the exciter from the ign and volt reg. Switched on the ign and the wiper fuse stayed intact, so at least I may have found a possible cause. Think I've got a spare alt kicking around the garage floor somewhere so I'll rig it up tomorrow and check it out, keep you posted nate, thanks for the reply and congrats on your spoils of victory last weekend :mrgreen:

by **Adrian Worman** » 11 Aug 2010 12:37

Success at last

Installed new ign e.c.u, voltage reg and ballast, new alternator and car started and ran perfect. Checked voltage at most every point and getting roughly 14 v on power circuit and 7 v on coil, just got to take the leap of faith and get it out on the street :roll:

by **dave-r** » 11 Aug 2010 14:01

Bet it was the alternator shorted out. :wink:

by **Adrian Worman** » 11 Aug 2010 14:52

Yeah your right, the field terminal was likely, I still think that the harness being messed with had an adverse effect on the alternator tho'. Never mind, at least I know most everything has been replaced now. Just need to get a new wiper motor switch now and then hopefully I might even make the last summer show at Billing :lol: