| Author |
Message |
wayne1230cars
Samba Member
Joined: April 05, 2010
Posts: 2685
Location: Canada
|
 Posted: Mon May 20, 2019 10:39 pm Post subject: 6 volt coil resistance readings |
 |
|
I am testing some spare 6 volt coils that I have. I am wondering if these resistance readings are acceptable and within specifications.
Coil 1) original short style coil - dated Dec. 1959
Primary resistance 1.5 ohms. Secondary resistance 5.3 k
Coil 2) Bosch silver long style. primary resistance 1.7 ohms secondary resistance 13 k.
Coil 3) unknown manufacturer - long style - primary resistance 1.3 ohms secondary resistance 9 k
I was surprised at the wide range of the secondary resistance readings. What should the optimal reading be?
_________________
1960 beetle
1970 beetle convertible |
|
| Back to top |
|
 |
tasb
The Distributor Distributor
Joined: April 27, 2002
Posts: 6371
Location: Pentwater, Michigan
|
| Posted: Tue May 21, 2019 1:02 am Post subject: Re: 6 volt coil resistance readings |
|
|
I've not encountered any short Bosch coils as early as 1959.
Your readings are fairly typical.
_________________
Roads Scholar &
1957 Kombi low mileage 36 hp governor equipped M 178 Slow Drag Winner 2014, 2015, 2018
1965 hardtop Deluxe Microbus owned since 1990 M 620 factory 12 v 1500cc
1961 (October)Single Cab- Road Trip Workhorse |
|
| Back to top |
|
|
wayne1230cars
Samba Member
Joined: April 05, 2010
Posts: 2685
Location: Canada
|
| Posted: Tue May 21, 2019 7:00 am Post subject: Re: 6 volt coil resistance readings |
|
|
Correction. All 3 coils measure about 4 3/8 inches as shown in pic. So none of these would be considered “short coils”? Bosch Coil is marked 6Q so June 1959? Is that coil within spec?
_________________
1960 beetle
1970 beetle convertible |
|
| Back to top |
|
|
tasb
The Distributor Distributor
Joined: April 27, 2002
Posts: 6371
Location: Pentwater, Michigan
|
| Posted: Tue May 21, 2019 9:13 am Post subject: Re: 6 volt coil resistance readings |
|
|
That one is showing marginally high resistance in the secondary winding but fine in the primary,. If it delivers a blue spark I'd give it a try.
_________________
Roads Scholar &
1957 Kombi low mileage 36 hp governor equipped M 178 Slow Drag Winner 2014, 2015, 2018
1965 hardtop Deluxe Microbus owned since 1990 M 620 factory 12 v 1500cc
1961 (October)Single Cab- Road Trip Workhorse |
|
| Back to top |
|
|
wayne1230cars
Samba Member
Joined: April 05, 2010
Posts: 2685
Location: Canada
|
| Posted: Tue May 21, 2019 7:54 pm Post subject: Re: 6 volt coil resistance readings |
|
|
| tasb wrote: |
| That one is showing marginally high resistance in the secondary winding but fine in the primary,. If it delivers a blue spark I'd give it a try. |
Thanks tasb. Will give that a try then. Good to have a spare coil that you know will work. Although in my 48 years of driving bugs, I’ve only had one coil go bad and that was in 1975 on my new ‘74 love bug with less than 20 k on it.
So, the coil with the low secondary resistance reading of 5.3 k ohms would not be the best choice for a spare. What problems could it exhibit?
_________________
1960 beetle
1970 beetle convertible |
|
| Back to top |
|
|
|
