Joined: Sat Mar 25 2006, 07:31PM
Location: Nebo, NC
Posts: 86
70 Newyorker,
Thanks for the diagram; it looks spot-for my system. And the information regarding the differing built-in resistance is priceless. However, you mention an NOS control head. By this, do you mean the plastic pushbutton switch in the dash? Or, unlike mine, does your car have ATC? I can't think of anything else in these systems which would match the description of a "control head". Just curious.
Control head = 5 push button vacuum/electric switch in dash. I do not have ACT either. Glad the info helped. I had a fun time digging thru the service manual looking for anything on why the blower has "two" speeds based on A/C or heat. Never did find anything mentioning this in the operation description, nor a reason for it. As for removing switches from under the dash on these cars, I'd sooner drop a hammer on my foot. It took me an hour to R+R the clock and over fifteen minutes to tighten a screw for the wiper switch.
Joined: Sat Mar 25 2006, 07:31PM
Location: Nebo, NC
Posts: 86
Thanks for the clarification and the photo. And a big "Amen" about switch (etc.) r & r.
BTW, considering that you have a '70, do you know what to do with the headlight rocker/toggle switch when it fails on the '67 - '70 cars (presuming that you don't want to hunt for NOS)? I found that the failure is usually in the switch's integrated circuit breaker and I developed a field update repair for this situation. The repair maintains the original look and operation of the switch and requires no wiring butchery if done properly. If ithis procedure is not common knowledge, I will be glad to post an online article about it on this site.
Guess I'm sort of hijacking my own thread here . . .
<span class='smallblacktext'>[ Edited Wed Mar 29 2006, 07:37AM ]</span>
Go for it! Submit it as an article for the Tech Articles.
Along those lines, but straying as well, I have had a flasher switch fail and was able to fix it by opening it and cleaning off all the old grease and applying fresh dielectric grease.
Joined: Sat Mar 25 2006, 07:31PM
Location: Nebo, NC
Posts: 86
70NEWYORKER, Thanks for the update. My blower output seems to be adequate sometimes, inadequate others with exactly the same equipment load on the system. Go figure. One observation: I have an accessory voltmeter on our car (factory ammeter inoperative: a future project) which shows almost 14 volts with no load (except ignition) but drops immediately to as little as 11 volts when I engage lights, wipers and heater blower. This is not at idle but rather when I am running down the road at 2,500+ rpm. Yet when I shut off all of the accessories, the voltage comes right back up and I never have a problem re-starting the car. I guess my question is: is it normal for a voltmeter to behave like an ammeter? And, if not, what would account for such a dramatic voltage drain?
Get your alternator and voltage regulator checked out. Off the top of my head, I'd say your alternator is going south; not able to put out enough amps.
