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Thumbing through my book I noticed a few capacitors shown that I do not have inline. Can anyone shed some light on what exactly they do and do I need them?
1.) directional signal
2.) blower motor. I did buy one for this but then my motor did not work so I took it off.
3.) stop lamp switch
Also, there is a filter assembly shown for the distributor. I do have a MSD upgrade. Do I need this too?
The capacitors were for RFI with the optional radio. If you're not hearing radio interference, you don't need them. I'm not sure whether the MSD needs the tach filter.
Last edited by Easy Mike; Mar 18, 2020 at 04:03 PM.
Capacitors are for 'signal smoothing'. They charge up and let current flow at a pre-programmmed rate. Yes, Mike is right they help with Radio Frequency Interference, but they also protect devices.
Spikes, surges and sags are bad for electronic equipment. Bulbs, motors et al.
In My factory, every piece of equipment has a capacitor.
As far as the MSD. I had to remove the Tach Filter since my tach rpm input comes from my MSD-6 box. When transferred to over the MSD-6 box (from Ramjet 350 elec ignition) I initially did not remove the tach filter and the tach would start bouncing quite erratically at about 3500 rpm. Since I removed the tach filter it works like a dream.
Originally Posted by Emeightch
Thumbing through my book I noticed a few capacitors shown that I do not have inline. Can anyone shed some light on what exactly they do and do I need them?
1.) directional signal
2.) blower motor. I did buy one for this but then my motor did not work so I took it off.
3.) stop lamp switch
Also, there is a filter assembly shown for the distributor. I do have a MSD upgrade. Do I need this too?
So I have the MSD HEI Distributor with no separate filter setup now. I’ve never had this out driving any distance on the road. Is this something I need to look into or check within the MSD details?
As for the capacitors, still on the fence. I don’t have a radio now and I would assume the RFI wouldn’t be an issue with today’s radios but am not sure.
The 2 capacitors under the dash fell apart and I never replaced them previously. However now I've gone to HEI and an electronic tach I'm getting some signal noise through the stereo which increases with rpm. Will be replacing the capacitors next time I have the dash out to try and fix it.
The 2 capacitors under the dash fell apart and I never replaced them previously. However now I've gone to HEI and an electronic tach I'm getting some signal noise through the stereo which increases with rpm. Will be replacing the capacitors next time I have the dash out to try and fix it.
You are getting what is commonly called "alternator" whine- that is leftover AC not filtered by the alternator's rectifier or generated by the HEI.
To solve the issue- an in-line noise filter is what you need-replacing the capacitors will not help. All they do is stop the popping noise when applying the brake-and/or turn signals when they blink.
So I have the MSD HEI Distributor with no separate filter setup now. I’ve never had this out driving any distance on the road. Is this something I need to look into or check within the MSD details?
As for the capacitors, still on the fence. I don’t have a radio now and I would assume the RFI wouldn’t be an issue with today’s radios but am not sure.
I'll say this for MOST modern radios -you shouldn't have problem- unless you do a lot of AM radio listening. However -there are some junk radios sold today that are almost impossible to install without getting noise- no shielding is used- cheap cables etc. The Corvette is notorious as the fiberglass does not shield like metal- hence the ignition shields used on many years.
The MSD is just looking for good clean power- IIRC the manual says to power of battery to reduce interference. The battery is the best source for electronics as it stabilizes the voltage and is a great filter. If you are not having any issues - I wouldn't worry about it.
Richard
Last edited by Richard454; Mar 18, 2020 at 09:45 PM.
Capacitors?
