Hello,
I am seeking help with my 1991 Vanagon that has a 2001 Jetta 1.9L TDI engine ALH conversion. With it being colder outside(I live near Philadelphia), I have been having issues starting my engine. With the compartment I have under my passenger seat, I only have space for a battery that is 7"x7"x11.5"(177.8mm x 177.8 mm x 292.1mm). When I got it back from the shop, my mechanic said that when he had it in the garage, it started good but when he tried starting it a couple days later when parked outside, the van wouldn't start. He said that I don't have the correct rated battery to start my TDI engine with it being colder out. The battery I have in it is a Bosche (part number 41-675B) with CCA @ 0F = 650 and CA @ 32F =780 . With the camping that I do, I have an auxiliary battery that I bring with me that operates a fan and I typically recharge it with jumper cables when it needs a charge. I don't typically camp for more than 5 days.

1. If I were to hook up another battery when cold out, would it assist starting my van during colder months?

2. Can I wire it so I can have a kill switch to the auxiliary battery so it charges it and does not overload my current system?

If anybody has done this before or can give me some advice, that would be awesome. Again, this is only an issue when it is cold outside. I thought about putting a bigger battery under the rear bench seat but I feel like that might be a pain.

Thanks

 

I'm curious about your Vanagon as they are only for USA market, you don't show your location in you profile. ETKA doesn't list Vanagon but ElsaWin does.

Manufacturer: VW, Date(s) Used: 08/1988-07/1989, Model: Vanagon, Engine Code: MV, 70Kw, 95PS, 2.1 Ltr, 4 Cyls, Remarks: North American Region (NAR):Type 2 Van, Air Cooled, W.L.E. Digifant
Manufacturer: VW, Date(s) Used: 08/1985-07/1992, Model: Vanagon, Engine Code: MV, 70Kw, 95PS, 2.1 Ltr, 4 Cyls, Remarks: North American Region (NAR):Type 2 Van, Air Cooled, Digifant
Manufacturer: VW, Date(s) Used: 01/1983-07/1985, Model: Vanagon, Engine Code: DH, 60Kw, 82PS, 1.9 Ltr, 4 Cyls, Remarks: North American Region (NAR): Type 2 Van, Air Cooled
Manufacturer: VW, Date(s) Used: 08/1987-07/1992, Model: Vanagon/Syncro, Engine Code: DG, 57Kw, 78PS, 1.9 Ltr, 4 Cyls, Remarks: North American Region (NAR): Type 2 Van, Air Cooled
Manufacturer: VW, Date(s) Used: 05/1979-12/1982, Model: Vanagon, Engine Code: CV, 51Kw, 70PS, 2.0 Ltr, 4 Cyls, Remarks: North American Region (NAR): Type 2 Van
Manufacturer: VW, Date(s) Used: 08/1981-07/1982, Model: Vanagon, Engine Code: CS, 37Kw, 50PS, 1.6 Ltr, 4 Cyls, Remarks: North American Region (NAR): Diesel, Type 2 Van

Manufacturer: VW, Date(s) Used: 11/1998-06/2004, Model: Jetta, Engine Code: ALH, 66Kw, 90PS, 1.9 Ltr, 4 Cyls, Remarks: USA ("USA"): Turbocharged Direct Injection (TDI) Timing belt

You could isolate the auxiliary battery. Jump starting with another battery will aid starting. Get your glow plug circuit checked out.