Singing the alternator blues

Topic: Singing the alternator blues (Read 3157 times) previous topic - next topic

Singing the alternator blues

Reply #30 – January 28, 2009, 09:41:51 PM

Quote from: softtouch;254127

That must an antique Dodge you are talking about. Back to the 6v days.

Well I suppose it may be antique to some of young fellas, but this goes back to the 60s and 12 volt systems.

Rod

Singing the alternator blues

Reply #31 – January 29, 2009, 02:56:08 PM

Well, back to the drawing board. Had to re-hook the ABS wires as they also control the brake boost. But now I think I'm seeing a pattern, especially since I saw some harebrained wiring the previous owner had done.

When I fire up the car, brake booster completely drained, the alternator charges normally. Once the brakes come up, the charge drops rapidly. This brings us to the harebrained wiring I saw. Apparently the high/low pressure switch must have quit working, so the previous owner direct wired the booster.

Sooo, current theory is once the booster comes up to max pressure, the little electric motor on the hydraulic booster starts drawing a pile of current, pulling down the 2G alternator. Any comments on the theory? Any idea how much current that hydraulic booster is supposed to pull?

Rod

Singing the alternator blues

Reply #32 – January 29, 2009, 04:29:38 PM

I like the theory.

Singing the alternator blues

Reply #33 – January 30, 2009, 09:21:47 AM

Quote from: DiamondSCattleCo;254316

Sooo, current theory is once the booster comes up to max pressure, the little electric motor on the hydraulic booster starts drawing a pile of current, pulling down the 2G alternator. Any comments on the theory? Any idea how much current that hydraulic booster is supposed to pull?

Rod

Not a clue on current, but I'd think less than 20A(motor isn't very large)... The motor is controlled by a relay(and the pressure switch) and should only run on start up, after using brakes, or once every 15 minutes or so to keep pressure up in the system... The relay is the front one of the pair that are located on the firewall near the ABS M/C assembly, it's a common problem...

NOTE Relay normally sticks causing the pump to run continually, even with switch off, I assume yours should be working or maybe the PO has it bypassed...

Both radiator fans running, heater blower on max, and the headlights on, will pull close to what a 2G is rated for... If you have some thumpin audio gear no wonder it keeps failing... BTWThe 88TC used a Hitachi 85A alternator because the Ford isn't up to the task... I don't think those swap direct to the '87 without some rewiring... Go with the 130A 3G, thats what I installed on mine...

Singing the alternator blues

Reply #34 – January 30, 2009, 12:00:18 PM

You should probably feel around the bottom of the steering column for heat, too. I've seen the ignition switches in these cars short to ground through the grease inside 'em - the grease builds up copper filings and becomes a conductor. In fact I had one get so hot it melted the aluminum body of the switch (that was in my '87 Sport). Also had one catch fire ('91 T-Bird).