BACKYARD MECHANIC: Propane heater, just to start?

Hey there, time traveller!
This article was published 31/07/2009 (5917 days ago), so information in it may no longer be current.

QUESTION: I have a five-speed, manual-shift 2003 Jetta TDI with a very annoying problem. When the outside temperature is about 0 C or below, the engine will not turn over. I have had the starter-solenoid assembly replaced without fixing the problem. I had noticed that by directing a source of heat for about five minutes at the clutch safety interlock switch, the engine would turn over and start normally. I had the switch replaced but the problem still persists. Apart from that, the car is a joy to operate and currently has 180,000 kilometres on the odometer. Any thoughts on a better resolution than carrying a small propane heater in the winter?

ANSWER: I had a similar problem back a decade ago and I don’t want to discourage you, but it took me three weeks to fix it. The reason for the long repair time was that the problem would only occur for about three minutes. Then the heat of my body inside the car would warm up the interior enough that it would start. I could only test it one time a day in that three-minute window because I had to let it cool down again.

On your car you have already pinpointed the problem down to the crank circuit, which runs from the ignition switch, through the clutch safety interlock switch and onto the starter solenoid. The problem is inside the car, or adding heat wouldn’t help, so the only remaining item to look at is the wiring to and from the clutch safety interlock switch. There is most likely a break in the wiring inside the insulation and when you add heat, the wire expands and makes a better contact. Then the engine will crank.

A careful inspection of the wiring near the clutch safety switch may identify abrasion or stress areas, but it is probably quicker to install a new wire in parallel to the existing wire and tape it to the harness. That is how I solved my car’s problem. It is a lot quicker and neater than opening up wiring harnesses.

 

QUESTION: I was wondering if you could help me with a huge problem I’m having finding a vehicle that I can drive. I have a rare condition called electromagnetic sensitivity (many people in Scandinavian countries have this) and find that the newer models have fairly high EMF fields. I am looking for a newer vehicle that has low electromagnetic fields in the driver’s seat and was wondering if you might have some advice on which models I could try — or how the wiring and/or electronic devices could be modified.

I have an EMF meter, which does help somewhat in detecting the vehicles with exceptionally high fields (e.g. Subarau Forester) but need to drive the vehicle for some time before I can tell if it is OK for me. Two vehicles that I find suitable are a 1994 Chrysler van (over 300,000 kilometres) which I would like to replace, and a 2001 Buick Century.

ANSWER: After doing a little research into your situation, I find a lot of debate on the subject, but very little research. I do know that some people are very sensitive to the high frequency noises that sometimes emit from electronics, so why not electromagnetic fields?

Any wire on the vehicle carrying electrical current through it will generate an electromagnetic field. The more current, the larger the field. While I have not had to deal with your situation, we do install shielding on some wiring when aftermarket business radios are installed to prevent the EMF from transferring between computer-controlled circuits and the radio signal circuits. Doing this can be as simple as wrapping the wiring harness in metal foil (we have used ordinary tin foil) and grounding this foil to the car body. This blocks the transmission of EMF.

Fibreglass-bodied cars such as the Corvette did this from the factory with their spark plug wiring to block transmissions through the fibreglass body and into the car interior. A metal firewall also blocks the transmissions. As for a newer car that has low EMF, this could be difficult, as most new cars are loaded with electronic controls and wiring. Look for one with as few options as possible. It may even be worth your time to investigate purchasing an older restored car from the 1960s or ’70s, as these had little electrical options and if restored properly can provide years of excellent service.

Jim Kerr is an experienced mechanic, instructor of automotive technology, freelance journalist and member of the Automobile Journalists’ Association of Canada.

kerr.jim@sasktel.net