pedlar17 Posted June 24, 2015 Report Share Posted June 24, 2015 My 1972 UK PI has a 15ACR alternator. This has just died, and I am looking to replace with either a 17 ACR if I can find one, or an 18 ACR 45 amp unit. I do not have anything extra on the vehicle so would like to keep as close to stock as possible. My question is, can the original ammeter still be used with the 18 ACR.? Many thanks Quote Link to post Share on other sites
RogerH Posted June 24, 2015 Report Share Posted June 24, 2015 The car circuitry will take as much as it needed. EG. If you were using 20amps with the 15ACR then you will continue to use 20amp with anything bigger. A bigger alternator will supply more but only if demanded. Go for the 18ACR 45amp jobby - you may be tempted to go for an 8 track tape deck. Roger Quote Link to post Share on other sites
pedlar17 Posted June 24, 2015 Author Report Share Posted June 24, 2015 Thanks Roger. Can the ammeter still be used as the wiring for the original 15ACR is different to the new 18ACR, and if so how to I connect it? Cheers Quote Link to post Share on other sites
snowric Posted June 24, 2015 Report Share Posted June 24, 2015 I believe you can use the original wiring and I did for some time. I fitted a bigger wire from the alternator to the ammeter and on to the battery for safety when I upgraded from a 45amp to a 60 amp alternator. The lucas ammeter is rated at +-30 amps but can take higher for short time periods (trust me I know). They told me that: alternator output 45amps - bosch fuel pump (10-15amps) and ignition and ancillaries (5amps) = max 30amps available to charge the battery and the wiring and alternator should take it. I probably overdid it. Snowy Quote Link to post Share on other sites
Sapphire72 Posted June 24, 2015 Report Share Posted June 24, 2015 If you take your old 15 ACR alternator to an automotive electric repair shop, it may be rebuildable for less cost then a new alternator. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.