Winkin' blinkin' and 'nod

[smilinsam]

Help!!...I am in desperate need of a wiring guru, cause my shade tree, 1960 knowledge is showing big time...and I'm working on a 1972 truck!...you can extrapolate to current day...well, you get the picture. Okay, here's my problem...the electrical system in my '72 camper special surges, causing the lights to flicker. It's done this since I bought the truck. I replaced the instrument cluster with an F-700 model, but I replaced every gauge with SW electrics. The new voltmeter registers about 13.5 at idle, but pegs 16 volts as you rev the engine (or drive)...it doesn't stay at 16v, but it bounces back and forth...turning the headlights on stabilizes it somewhat, but they flicker slightly...turn signals make the gauge flicker. I completely rewired the instrument cluster but connected it to the stock harness. I by-passed the constant voltage regulator and went directly to the gauges with a common "hot." My reasoning was, I've never had to have a regulator on any of my builds, using aftermarket gauges, so, I didn't think I needed one here. I get a constant reading on the other gauges (oil press., temp, fuel, tach) and the lights on the gauges don't flicker (that I can see). I have replaced the alternator, regulator, solenoid and cleaned every ground that I could see, replaced all funky wires and checked most connectors...still blinkin'!!! By the way, I eliminated all the old looms for the camper, which were not connected, so I've pretty much got it down to basics. So...does anyone have any similar experience, or am I doomed to putting a completely new harness in?....I know that's probably the cleanest solution but a wiring harness ain't cheap!...and I was hoping to save enough to get "Big Red" painted this spring. Will appreciate any and all advice...I'm walking around with a tic!...and people don't have to question whether or not I'm crazy!

[mnkeeking]

I had a similar problem and mine got worse until one night my wife and I were driving home and BAM! no lights at all. Your problem sounds like you need to replace the dimmer switch for your headlights, which is located on the floor near your left foot. Your headlight power runs through that switch and if it's bad it causes lighting problems. The PO of my truck drilled two small holes just above the e-brake warning light in the dash, so I bought and installed an on-off-on three pole switch and moved my dimmer off the floor mostly because I'm an above knee amputee and drive with my left foot. Can't hit the dimmer switch without taking my foot off the brake so I moved it. No more lighting issues. Original floor dimmer switch is about $9 at Oreilly's if you want to keep it on the floor.

Take care,
Joe
http://www.oreillyauto.com/site/c/detai ... mer+switch

[tbone6]

Also, be suspicious of the headlight switch. That switch has a lot of current running through it and it is probably pretty old. If it turns out to be the headlight switch, you may want to consider adding a 40 amp relay to handle the load.

[smilinsam]

Hey, thanks all for advice...it may have something to do with the light or dimmer switch, as I have not replaced either of those...but the gauge (ammeter originally in stock cluster, and a SW voltmeter in new F-700 cluster) fluctuates whether lights are on or off. I'm going to try a new constant voltage regulator as the old one may have been defective, and I'll run the "hot" wires thru it. Does anyone know if Ford was the only one to use this regulator on early alternator setups? I've had a number of 60's Ford cars and trucks and never run into this before...of course, they all had a stock dash and mostly stock wiring, so this problem never presented itself. A good mechanic I talked to said it's a bad ground somewhere, and the current is trying to find a way out...so, more detective work soon as The Lone Star state gets warm again!

[bluef250]

If you are getting 16 volts from the alternator, I would investigate this first. Where are you measuring this voltage? The voltage suggests a bad alternator diode but the voltage regulator could also be the culpirt. Check the alternator belt tension. Is the belt slipping? The alternator should put out 14.2 to 14.6 volts but is capable of putting out much more. The voltage regulator maintains the output.

The 16 volt output also is not good for the battery.

[Art]

x2 on the voltage regulator