Q: I am reaching out to you as a last resort with a vexing but widespread problem. My problem is what to do when you need to jump-start an antique car (1931 Model A Ford) with a 6VDC system when the contributor auto is a modern 12VDC automobile. This problem is very widespread. There are more than 1,700 Model A owners listed in California with many of them owning multiple cars. If one considers all the antique cars in America, I would think someone has the answer but it has not been publicized. I’m 86 and the car is 83, so we don’t have a heck of lot of time to get on with this problem. (The bumpers on my car don’t match the modern stylish bumpers) so a push is not the answer. I will appreciate your help with the problem.

— G.C. (Jerry) Williams

A: This is a tough one, and I believe your car may be the most mature I’ve contemplated. I performed quite a bit of research and was unable to come up with a jumpstarting adaptor or method that is prudent to use. Connecting a modern vehicle’s 12-volt automobile battery to a 6-volt system causes a huge in-rush of electrical current to the 6-volt car’s battery and electrical system in addition to possibly wreaking havoc with the sensitive electronics onboard the newer vehicle. For about every five people that say they’ve done this successfully (myself included), one hears about one or two incidents of a battery explosion or other malady. Do not try this.

I contemplated construction of a voltage dropping device midjumper cable but was put off by issues of practicality, weight and safety. My best suggestion would be to build a 6-volt jumper pack using an Optima Redtop AGM 6V battery (compact, lightweight, spill-proof and highly efficient) and some robust jumper cables. This will be a bit of a pain to bring along but may be popular at certain times with your friends! If anyone knows of a more useful solution, I’d be happy to learn of it and pass the information forward.

Q: I just finished giving my car a major inside and out cleaning and couldn’t help but notice some of the wiring is of different colors, other than black. I’m talking about the ribbed plastic tubing around the wires. Is this for a reason?

— Jim L.

A: Yes. Orange, yellow or blue wiring looms are a warning that the circuit within is either of higher than typical voltage and/or requires special techniques when servicing. Orange is the most critical of the colors — this indicates potentially dangerous high voltage of up to 650V and should be treated with care. This color would most likely be seen on a hybrid or electric vehicle. Yellow is typically used to indicate SRS (airbag and pretensioner) circuits, connectors and components, and along with blue it may also be used in some 12-42 volt power steering or other systems. A twisted pair of wires or wires shielded with Mylar foil may be seen in certain applications where intruding electrical interference can’t be tolerated. Examples are vehicle system networks and some electronic system sensors.

— Bergholdt teaches automotive technology. Email questions to under-the-hood@earthlink.net.