| metalart | -- 08-16-2023 @ 5:39 PM |
|
HI, Can an electric fuel pump with Neg Earth be connected to our early fords with their Pos Earth? If so would the pump power supply connect to the chassis and earth go back to the ignition switch? Thanks in advance. Metalart.
|
|
| JayChicago | -- 08-17-2023 @ 8:10 AM |
|
I had that same question when installing an electric pump on my '37 streetrod. But then it was pointed out to me that the pump has two wires, is not grounded by the mounting base. Since your power supply wire is providing negative, connect power to the - wire on the pump. The + wire on the pump gets attached to the frame.
|
|
| wmsteed | -- 08-17-2023 @ 9:23 AM |
|
A word or two of caution about hooking an electric pump, or any other accessory to the ignition switch. The original Early Ford V8 ignition switch is not designed to carry the load of accessories, just a heater can be marginal. Bill 36 5 win delx cpe
|
|
| 51woodie | -- 08-17-2023 @ 12:55 PM |
|
I installed an Airtex pump on my stock '46 Super Deluxe, which is + ground. The white wire went to ground and the black is fed through a switch from the lighting circuit breaker. I only use it to "prime" the carb after the car has sat for a week or more.
|
|
| alanwoodieman | -- 08-17-2023 @ 4:37 PM |
|
I just finished rewiring an electric pump-remember these push better than pull--used a push button switch with wire for power run thru a fuse and back to the pump push button--this allows priming but not running with this set up
|
|
| metalart | -- 08-17-2023 @ 6:39 PM |
|
Sincere thanks to everyone for your replies. They are all very helpful. I am finding that dealing with Pos earth for the first time is a bit of a mind bender. After years working on Neg earth, I find it hard to believe a manufacturer of any kind would put live power through a car chassis. ( given that power goes from Pos to Neg). It's a wonder that batteries don't go flat from the chassis going to earth with rain water etc. (Or am I on the wrong track here?) So, following on from your posts, I might consider putting a relay between the chassis and the pump and switch it with a push button as suggested. This may help in event of an accident by keeping the pump off and take the load off the ignition switch. Appreciate any further thoughts. Regards, Metalart.
|
|
| Drbrown | -- 08-18-2023 @ 8:12 AM |
|
I have a 12v negative ground system. I agree the ignition switch should not be used to avoid over-loading that circuit, and for safety reasons - ignition switches can fail (tho rarely) in open or closed position. Personally I also avoided using a relay because if the relay switch or relay itself faults and closes, the pump will run constantly - would one know ? So I use an illuminated toggle switch with fuse for complete control of the pump. Mechanically toggle switches are simple devices. I use my Airtex pump only for priming the carb - about 5 seconds. However, once I used it continuously to get home when my mechanical pump seemed to have a failed. In a vehicle accident, as long as the toggle switch is in off position, I believe the pump would be unable to operate. This message was edited by Drbrown on 8-18-23 @ 8:17 AM
|
|
| metalart | -- 08-23-2023 @ 5:21 PM |
|
Thanks Doc and thanks to all other posts. regards, Metalart
|
|
| woodiewagon46 | -- 08-24-2023 @ 3:37 PM |
|
There was an article about using a relay as a safety switch in the V-8 Times, 1999 July/August issue.
|
|
| EFV-8 Club Forum : | https://www.earlyfordv8.org/forum |
| Topic: | https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=16615 |