So if you didn’t know, here at MAKE, we have an old Mercedes Firetruck (it’s actually a hose/ladder truck) that built in Germany during the 1970s. Some of you may have seen the truck in the past, at various events, but for a long time, the firetruck has just been sitting around, in dire need of maintenance. There were several issues we had to overcome to get the truck running again. For one, it would not start and the wiring was pretty bad, so nothing worked properly. We were able to get it working for the Oakland Mini Maker Faire last year and hope to bring it out for more events in the future.
The first thing we did was to get the truck running, which was an interesting task because of the condition everything was in. We checked all the basic things, such as the starter, made sure power was going where it’s supposed to be go, the fuses and the contactor were still intact (which on this truck is used during starting, since the truck starts at 24 volts). After some further testing and bypassing, we determined the reason it was not starting was that one of the two 12 volt batteries had a bad post and would not allow enough current to flow. After replacing the battery, it starts up every time without any issues.
The next thing we did was to get all the lights working. This included the emergency lights, brake lights, reverse lights, fog lights, dash lights, and the lights that are inside the truck. Most of the issues with lighting were due to old fuses which we are slowly replacing with blade fuses. At first, we thought all the emergency lights were broken, but it turned out that the siren had to be switched on to power the emergency light circuit. (The siren is really loud as you can hear in the video). We bypassed the siren circuit, and now, all the emergency lights work even when the siren is not running.
We are still restoring it back to proper working condition and will soon be adding some awesome mods!
Written by MAKE Engineering Intern Brain Melani
[Photos by Gregory Hayes]